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Diffstat (limited to 'shell/hush.c')
| -rw-r--r-- | shell/hush.c | 4749 |
1 files changed, 4749 insertions, 0 deletions
diff --git a/shell/hush.c b/shell/hush.c new file mode 100644 index 0000000..4212729 --- /dev/null +++ b/shell/hush.c @@ -0,0 +1,4749 @@ +/* vi: set sw=4 ts=4: */ +/* + * sh.c -- a prototype Bourne shell grammar parser + * Intended to follow the original Thompson and Ritchie + * "small and simple is beautiful" philosophy, which + * incidentally is a good match to today's BusyBox. + * + * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org> + * + * Credits: + * The parser routines proper are all original material, first + * written Dec 2000 and Jan 2001 by Larry Doolittle. The + * execution engine, the builtins, and much of the underlying + * support has been adapted from busybox-0.49pre's lash, which is + * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> + * written by Erik Andersen <andersen@codepoet.org>. That, in turn, + * is based in part on ladsh.c, by Michael K. Johnson and Erik W. + * Troan, which they placed in the public domain. I don't know + * how much of the Johnson/Troan code has survived the repeated + * rewrites. + * + * Other credits: + * o_addchr() derived from similar w_addchar function in glibc-2.2. + * setup_redirect(), redirect_opt_num(), and big chunks of main() + * and many builtins derived from contributions by Erik Andersen + * miscellaneous bugfixes from Matt Kraai. + * + * There are two big (and related) architecture differences between + * this parser and the lash parser. One is that this version is + * actually designed from the ground up to understand nearly all + * of the Bourne grammar. The second, consequential change is that + * the parser and input reader have been turned inside out. Now, + * the parser is in control, and asks for input as needed. The old + * way had the input reader in control, and it asked for parsing to + * take place as needed. The new way makes it much easier to properly + * handle the recursion implicit in the various substitutions, especially + * across continuation lines. + * + * Bash grammar not implemented: (how many of these were in original sh?) + * $_ + * &> and >& redirection of stdout+stderr + * Brace Expansion + * Tilde Expansion + * fancy forms of Parameter Expansion + * aliases + * Arithmetic Expansion + * <(list) and >(list) Process Substitution + * reserved words: select, function + * Here Documents ( << word ) + * Functions + * Major bugs: + * job handling woefully incomplete and buggy (improved --vda) + * to-do: + * port selected bugfixes from post-0.49 busybox lash - done? + * change { and } from special chars to reserved words + * builtins: return, trap, ulimit + * test magic exec with redirection only + * check setting of global_argc and global_argv + * follow IFS rules more precisely, including update semantics + * figure out what to do with backslash-newline + * propagate syntax errors, die on resource errors? + * continuation lines, both explicit and implicit - done? + * memory leak finding and plugging - done? + * maybe change charmap[] to use 2-bit entries + * + * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. + */ + +#include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */ +#include <glob.h> +/* #include <dmalloc.h> */ +#if ENABLE_HUSH_CASE +#include <fnmatch.h> +#endif + +#define HUSH_VER_STR "0.91" + +#if !BB_MMU && ENABLE_HUSH_TICK +//#undef ENABLE_HUSH_TICK +//#define ENABLE_HUSH_TICK 0 +#warning On NOMMU, hush command substitution is dangerous. +#warning Dont use it for commands which produce lots of output. +#warning For more info see shell/hush.c, generate_stream_from_list(). +#endif + +#if !BB_MMU && ENABLE_HUSH_JOB +#undef ENABLE_HUSH_JOB +#define ENABLE_HUSH_JOB 0 +#endif + +#if !ENABLE_HUSH_INTERACTIVE +#undef ENABLE_FEATURE_EDITING +#define ENABLE_FEATURE_EDITING 0 +#undef ENABLE_FEATURE_EDITING_FANCY_PROMPT +#define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0 +#endif + + +/* Keep unconditionally on for now */ +#define HUSH_DEBUG 1 +/* In progress... */ +#define ENABLE_HUSH_FUNCTIONS 0 + + +/* If you comment out one of these below, it will be #defined later + * to perform debug printfs to stderr: */ +#define debug_printf(...) do {} while (0) +/* Finer-grained debug switches */ +#define debug_printf_parse(...) do {} while (0) +#define debug_print_tree(a, b) do {} while (0) +#define debug_printf_exec(...) do {} while (0) +#define debug_printf_env(...) do {} while (0) +#define debug_printf_jobs(...) do {} while (0) +#define debug_printf_expand(...) do {} while (0) +#define debug_printf_glob(...) do {} while (0) +#define debug_printf_list(...) do {} while (0) +#define debug_printf_subst(...) do {} while (0) +#define debug_printf_clean(...) do {} while (0) + +#ifndef debug_printf +#define debug_printf(...) fprintf(stderr, __VA_ARGS__) +#endif + +#ifndef debug_printf_parse +#define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__) +#endif + +#ifndef debug_printf_exec +#define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__) +#endif + +#ifndef debug_printf_env +#define debug_printf_env(...) fprintf(stderr, __VA_ARGS__) +#endif + +#ifndef debug_printf_jobs +#define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__) +#define DEBUG_JOBS 1 +#else +#define DEBUG_JOBS 0 +#endif + +#ifndef debug_printf_expand +#define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__) +#define DEBUG_EXPAND 1 +#else +#define DEBUG_EXPAND 0 +#endif + +#ifndef debug_printf_glob +#define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__) +#define DEBUG_GLOB 1 +#else +#define DEBUG_GLOB 0 +#endif + +#ifndef debug_printf_list +#define debug_printf_list(...) fprintf(stderr, __VA_ARGS__) +#endif + +#ifndef debug_printf_subst +#define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__) +#endif + +#ifndef debug_printf_clean +/* broken, of course, but OK for testing */ +static const char *indenter(int i) +{ + static const char blanks[] ALIGN1 = + " "; + return &blanks[sizeof(blanks) - i - 1]; +} +#define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__) +#define DEBUG_CLEAN 1 +#endif + +#if DEBUG_EXPAND +static void debug_print_strings(const char *prefix, char **vv) +{ + fprintf(stderr, "%s:\n", prefix); + while (*vv) + fprintf(stderr, " '%s'\n", *vv++); +} +#else +#define debug_print_strings(prefix, vv) ((void)0) +#endif + +/* + * Leak hunting. Use hush_leaktool.sh for post-processing. + */ +#ifdef FOR_HUSH_LEAKTOOL +/* suppress "warning: no previous prototype..." */ +void *xxmalloc(int lineno, size_t size); +void *xxrealloc(int lineno, void *ptr, size_t size); +char *xxstrdup(int lineno, const char *str); +void xxfree(void *ptr); +void *xxmalloc(int lineno, size_t size) +{ + void *ptr = xmalloc((size + 0xff) & ~0xff); + fprintf(stderr, "line %d: malloc %p\n", lineno, ptr); + return ptr; +} +void *xxrealloc(int lineno, void *ptr, size_t size) +{ + ptr = xrealloc(ptr, (size + 0xff) & ~0xff); + fprintf(stderr, "line %d: realloc %p\n", lineno, ptr); + return ptr; +} +char *xxstrdup(int lineno, const char *str) +{ + char *ptr = xstrdup(str); + fprintf(stderr, "line %d: strdup %p\n", lineno, ptr); + return ptr; +} +void xxfree(void *ptr) +{ + fprintf(stderr, "free %p\n", ptr); + free(ptr); +} +#define xmalloc(s) xxmalloc(__LINE__, s) +#define xrealloc(p, s) xxrealloc(__LINE__, p, s) +#define xstrdup(s) xxstrdup(__LINE__, s) +#define free(p) xxfree(p) +#endif + + +/* Do we support ANY keywords? */ +#if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE +#define HAS_KEYWORDS 1 +#define IF_HAS_KEYWORDS(...) __VA_ARGS__ +#define IF_HAS_NO_KEYWORDS(...) +#else +#define HAS_KEYWORDS 0 +#define IF_HAS_KEYWORDS(...) +#define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__ +#endif + + +#define SPECIAL_VAR_SYMBOL 3 +#define PARSEFLAG_EXIT_FROM_LOOP 1 + +typedef enum redir_type { + REDIRECT_INPUT = 1, + REDIRECT_OVERWRITE = 2, + REDIRECT_APPEND = 3, + REDIRECT_HEREIS = 4, + REDIRECT_IO = 5 +} redir_type; + +/* The descrip member of this structure is only used to make + * debugging output pretty */ +static const struct { + int mode; + signed char default_fd; + char descrip[3]; +} redir_table[] = { + { 0, 0, "()" }, + { O_RDONLY, 0, "<" }, + { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" }, + { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" }, + { O_RDONLY, -1, "<<" }, + { O_RDWR, 1, "<>" } +}; + +typedef enum pipe_style { + PIPE_SEQ = 1, + PIPE_AND = 2, + PIPE_OR = 3, + PIPE_BG = 4, +} pipe_style; + +typedef enum reserved_style { + RES_NONE = 0, +#if ENABLE_HUSH_IF + RES_IF , + RES_THEN , + RES_ELIF , + RES_ELSE , + RES_FI , +#endif +#if ENABLE_HUSH_LOOPS + RES_FOR , + RES_WHILE , + RES_UNTIL , + RES_DO , + RES_DONE , +#endif +#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE + RES_IN , +#endif +#if ENABLE_HUSH_CASE + RES_CASE , + /* two pseudo-keywords support contrived "case" syntax: */ + RES_MATCH , /* "word)" */ + RES_CASEI , /* "this command is inside CASE" */ + RES_ESAC , +#endif + RES_XXXX , + RES_SNTX +} reserved_style; + +struct redir_struct { + struct redir_struct *next; + char *rd_filename; /* filename */ + int fd; /* file descriptor being redirected */ + int dup; /* -1, or file descriptor being duplicated */ + smallint /*enum redir_type*/ rd_type; +}; + +struct command { + pid_t pid; /* 0 if exited */ + int assignment_cnt; /* how many argv[i] are assignments? */ + smallint is_stopped; /* is the command currently running? */ + smallint grp_type; + struct pipe *group; /* if non-NULL, this "prog" is {} group, + * subshell, or a compound statement */ + char **argv; /* command name and arguments */ + struct redir_struct *redirects; /* I/O redirections */ +}; +/* argv vector may contain variable references (^Cvar^C, ^C0^C etc) + * and on execution these are substituted with their values. + * Substitution can make _several_ words out of one argv[n]! + * Example: argv[0]=='.^C*^C.' here: echo .$*. + * References of the form ^C`cmd arg^C are `cmd arg` substitutions. + */ +#define GRP_NORMAL 0 +#define GRP_SUBSHELL 1 +#if ENABLE_HUSH_FUNCTIONS +#define GRP_FUNCTION 2 +#endif + +struct pipe { + struct pipe *next; + int num_cmds; /* total number of commands in job */ + int alive_cmds; /* number of commands running (not exited) */ + int stopped_cmds; /* number of commands alive, but stopped */ +#if ENABLE_HUSH_JOB + int jobid; /* job number */ + pid_t pgrp; /* process group ID for the job */ + char *cmdtext; /* name of job */ +#endif + struct command *cmds; /* array of commands in pipe */ + smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */ + IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */ + IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */ +}; + +/* This holds pointers to the various results of parsing */ +struct parse_context { + struct command *command; + struct pipe *list_head; + struct pipe *pipe; + struct redir_struct *pending_redirect; +#if HAS_KEYWORDS + smallint ctx_res_w; + smallint ctx_inverted; /* "! cmd | cmd" */ +#if ENABLE_HUSH_CASE + smallint ctx_dsemicolon; /* ";;" seen */ +#endif + int old_flag; /* bitmask of FLAG_xxx, for figuring out valid reserved words */ + struct parse_context *stack; +#endif +}; + +/* On program start, environ points to initial environment. + * putenv adds new pointers into it, unsetenv removes them. + * Neither of these (de)allocates the strings. + * setenv allocates new strings in malloc space and does putenv, + * and thus setenv is unusable (leaky) for shell's purposes */ +#define setenv(...) setenv_is_leaky_dont_use() +struct variable { + struct variable *next; + char *varstr; /* points to "name=" portion */ + int max_len; /* if > 0, name is part of initial env; else name is malloced */ + smallint flg_export; /* putenv should be done on this var */ + smallint flg_read_only; +}; + +typedef struct o_string { + char *data; + int length; /* position where data is appended */ + int maxlen; + /* Misnomer! it's not "quoting", it's "protection against globbing"! + * (by prepending \ to *, ?, [ and to \ too) */ + smallint o_quote; + smallint o_glob; + smallint nonnull; + smallint has_empty_slot; + smallint o_assignment; /* 0:maybe, 1:yes, 2:no */ +} o_string; +enum { + MAYBE_ASSIGNMENT = 0, + DEFINITELY_ASSIGNMENT = 1, + NOT_ASSIGNMENT = 2, + WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */ +}; +/* Used for initialization: o_string foo = NULL_O_STRING; */ +#define NULL_O_STRING { NULL } + +/* I can almost use ordinary FILE*. Is open_memstream() universally + * available? Where is it documented? */ +typedef struct in_str { + const char *p; + /* eof_flag=1: last char in ->p is really an EOF */ + char eof_flag; /* meaningless if ->p == NULL */ + char peek_buf[2]; +#if ENABLE_HUSH_INTERACTIVE + smallint promptme; + smallint promptmode; /* 0: PS1, 1: PS2 */ +#endif + FILE *file; + int (*get) (struct in_str *); + int (*peek) (struct in_str *); +} in_str; +#define i_getch(input) ((input)->get(input)) +#define i_peek(input) ((input)->peek(input)) + +enum { + CHAR_ORDINARY = 0, + CHAR_ORDINARY_IF_QUOTED = 1, /* example: *, # */ + CHAR_IFS = 2, /* treated as ordinary if quoted */ + CHAR_SPECIAL = 3, /* example: $ */ +}; + +enum { + BC_BREAK = 1, + BC_CONTINUE = 2, +}; + + +/* "Globals" within this file */ + +/* Sorted roughly by size (smaller offsets == smaller code) */ +struct globals { +#if ENABLE_HUSH_INTERACTIVE + /* 'interactive_fd' is a fd# open to ctty, if we have one + * _AND_ if we decided to act interactively */ + int interactive_fd; + const char *PS1; + const char *PS2; +#endif +#if ENABLE_FEATURE_EDITING + line_input_t *line_input_state; +#endif + pid_t root_pid; + pid_t last_bg_pid; +#if ENABLE_HUSH_JOB + int run_list_level; + pid_t saved_tty_pgrp; + int last_jobid; + struct pipe *job_list; + struct pipe *toplevel_list; + smallint ctrl_z_flag; +#endif +#if ENABLE_HUSH_LOOPS + smallint flag_break_continue; +#endif + smallint fake_mode; + /* these three support $?, $#, and $1 */ + smalluint last_return_code; + char **global_argv; + int global_argc; +#if ENABLE_HUSH_LOOPS + unsigned depth_break_continue; + unsigned depth_of_loop; +#endif + const char *ifs; + const char *cwd; + struct variable *top_var; /* = &G.shell_ver (set in main()) */ + struct variable shell_ver; +#if ENABLE_FEATURE_SH_STANDALONE + struct nofork_save_area nofork_save; +#endif +#if ENABLE_HUSH_JOB + sigjmp_buf toplevel_jb; +#endif + unsigned char charmap[256]; + char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2]; +}; + +#define G (*ptr_to_globals) +/* Not #defining name to G.name - this quickly gets unwieldy + * (too many defines). Also, I actually prefer to see when a variable + * is global, thus "G." prefix is a useful hint */ +#define INIT_G() do { \ + SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \ +} while (0) + + +#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n" + +#if 1 +/* Normal */ +static void syntax(const char *msg) +{ +#if ENABLE_HUSH_INTERACTIVE + /* Was using fancy stuff: + * (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...) + * but it SEGVs. ?! Oh well... explicit temp ptr works around that */ + void FAST_FUNC (*fp)(const char *s, ...); + fp = (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die); + fp(msg ? "%s: %s" : "syntax error", "syntax error", msg); +#else + bb_error_msg_and_die(msg ? "%s: %s" : "syntax error", "syntax error", msg); +#endif +} + +#else +/* Debug */ +static void syntax_lineno(int line) +{ +#if ENABLE_HUSH_INTERACTIVE + void FAST_FUNC (*fp)(const char *s, ...); + fp = (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die); + fp("syntax error hush.c:%d", line); +#else + bb_error_msg_and_die("syntax error hush.c:%d", line); +#endif +} +#define syntax(str) syntax_lineno(__LINE__) +#endif + +/* Index of subroutines: */ +/* in_str manipulations: */ +static int static_get(struct in_str *i); +static int static_peek(struct in_str *i); +static int file_get(struct in_str *i); +static int file_peek(struct in_str *i); +static void setup_file_in_str(struct in_str *i, FILE *f); +static void setup_string_in_str(struct in_str *i, const char *s); +/* "run" the final data structures: */ +#if !defined(DEBUG_CLEAN) +#define free_pipe_list(head, indent) free_pipe_list(head) +#define free_pipe(pi, indent) free_pipe(pi) +#endif +static int free_pipe_list(struct pipe *head, int indent); +static int free_pipe(struct pipe *pi, int indent); +/* really run the final data structures: */ +typedef struct nommu_save_t { + char **new_env; + char **old_env; + char **argv; +} nommu_save_t; +#if BB_MMU +#define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \ + pseudo_exec_argv(argv, assignment_cnt, argv_expanded) +#define pseudo_exec(nommu_save, command, argv_expanded) \ + pseudo_exec(command, argv_expanded) +#endif +static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded) NORETURN; +static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded) NORETURN; +static int setup_redirects(struct command *prog, int squirrel[]); +static int run_list(struct pipe *pi); +static int run_pipe(struct pipe *pi); +/* data structure manipulation: */ +static int setup_redirect(struct parse_context *ctx, int fd, redir_type style, struct in_str *input); +static void initialize_context(struct parse_context *ctx); +static int done_word(o_string *dest, struct parse_context *ctx); +static int done_command(struct parse_context *ctx); +static void done_pipe(struct parse_context *ctx, pipe_style type); +/* primary string parsing: */ +static int redirect_dup_num(struct in_str *input); +static int redirect_opt_num(o_string *o); +#if ENABLE_HUSH_TICK +static int process_command_subs(o_string *dest, + struct in_str *input, const char *subst_end); +#endif +static int parse_group(o_string *dest, struct parse_context *ctx, struct in_str *input, int ch); +static const char *lookup_param(const char *src); +static int handle_dollar(o_string *dest, + struct in_str *input); +static int parse_stream(o_string *dest, struct parse_context *ctx, struct in_str *input0, const char *end_trigger); +/* setup: */ +static int parse_and_run_stream(struct in_str *inp, int parse_flag); +static int parse_and_run_string(const char *s, int parse_flag); +static int parse_and_run_file(FILE *f); +/* job management: */ +static int checkjobs(struct pipe* fg_pipe); +#if ENABLE_HUSH_JOB +static int checkjobs_and_fg_shell(struct pipe* fg_pipe); +static void insert_bg_job(struct pipe *pi); +static void remove_bg_job(struct pipe *pi); +static void delete_finished_bg_job(struct pipe *pi); +#else +int checkjobs_and_fg_shell(struct pipe* fg_pipe); /* never called */ +#endif +/* local variable support */ +static char **expand_strvec_to_strvec(char **argv); +/* used for eval */ +static char *expand_strvec_to_string(char **argv); +/* used for expansion of right hand of assignments */ +static char *expand_string_to_string(const char *str); +static struct variable *get_local_var(const char *name); +static int set_local_var(char *str, int flg_export); +static void unset_local_var(const char *name); + + +static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR; + + +static int glob_needed(const char *s) +{ + while (*s) { + if (*s == '\\') + s++; + if (*s == '*' || *s == '[' || *s == '?') + return 1; + s++; + } + return 0; +} + +static int is_assignment(const char *s) +{ + if (!s || !(isalpha(*s) || *s == '_')) + return 0; + s++; + while (isalnum(*s) || *s == '_') + s++; + return *s == '='; +} + +/* Replace each \x with x in place, return ptr past NUL. */ +static char *unbackslash(char *src) +{ + char *dst = src; + while (1) { + if (*src == '\\') + src++; + if ((*dst++ = *src++) == '\0') + break; + } + return dst; +} + +static char **add_strings_to_strings(char **strings, char **add) +{ + int i; + unsigned count1; + unsigned count2; + char **v; + + v = strings; + count1 = 0; + if (v) { + while (*v) { + count1++; + v++; + } + } + count2 = 0; + v = add; + while (*v) { + count2++; + v++; + } + v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*)); + v[count1 + count2] = NULL; + i = count2; + while (--i >= 0) + v[count1 + i] = add[i]; + return v; +} + +static char **add_string_to_strings(char **strings, char *add) +{ + char *v[2]; + v[0] = add; + v[1] = NULL; + return add_strings_to_strings(strings, v); +} + +static void putenv_all(char **strings) +{ + if (!strings) + return; + while (*strings) { + debug_printf_env("putenv '%s'\n", *strings); + putenv(*strings++); + } +} + +static char **putenv_all_and_save_old(char **strings) +{ + char **old = NULL; + char **s = strings; + + if (!strings) + return old; + while (*strings) { + char *v, *eq; + + eq = strchr(*strings, '='); + if (eq) { + *eq = '\0'; + v = getenv(*strings); + *eq = '='; + if (v) { + /* v points to VAL in VAR=VAL, go back to VAR */ + v -= (eq - *strings) + 1; + old = add_string_to_strings(old, v); + } + } + strings++; + } + putenv_all(s); + return old; +} + +static void free_strings_and_unsetenv(char **strings, int unset) +{ + char **v; + + if (!strings) + return; + + v = strings; + while (*v) { + if (unset) { + char *copy; + /* *strchrnul(*v, '=') = '\0'; -- BAD + * In case *v was putenv'ed, we can't + * unsetenv(*v) after taking out '=': + * it won't work, env is modified by taking out! + * horror :( */ + copy = xstrndup(*v, strchrnul(*v, '=') - *v); + debug_printf_env("unsetenv '%s'\n", copy); + unsetenv(copy); + free(copy); + } + free(*v++); + } + free(strings); +} + +static void free_strings(char **strings) +{ + free_strings_and_unsetenv(strings, 0); +} + + +/* Function prototypes for builtins */ +static int builtin_cd(char **argv); +static int builtin_echo(char **argv); +static int builtin_eval(char **argv); +static int builtin_exec(char **argv); +static int builtin_exit(char **argv); +static int builtin_export(char **argv); +#if ENABLE_HUSH_JOB +static int builtin_fg_bg(char **argv); +static int builtin_jobs(char **argv); +#endif +#if ENABLE_HUSH_HELP +static int builtin_help(char **argv); +#endif +static int builtin_pwd(char **argv); +static int builtin_read(char **argv); +static int builtin_test(char **argv); +static int builtin_true(char **argv); +static int builtin_set(char **argv); +static int builtin_shift(char **argv); +static int builtin_source(char **argv); +static int builtin_umask(char **argv); +static int builtin_unset(char **argv); +#if ENABLE_HUSH_LOOPS +static int builtin_break(char **argv); +static int builtin_continue(char **argv); +#endif +//static int builtin_not_written(char **argv); + +/* Table of built-in functions. They can be forked or not, depending on + * context: within pipes, they fork. As simple commands, they do not. + * When used in non-forking context, they can change global variables + * in the parent shell process. If forked, of course they cannot. + * For example, 'unset foo | whatever' will parse and run, but foo will + * still be set at the end. */ +struct built_in_command { + const char *cmd; + int (*function)(char **argv); +#if ENABLE_HUSH_HELP + const char *descr; +#define BLTIN(cmd, func, help) { cmd, func, help } +#else +#define BLTIN(cmd, func, help) { cmd, func } +#endif +}; + +/* For now, echo and test are unconditionally enabled. + * Maybe make it configurable? */ +static const struct built_in_command bltins[] = { + BLTIN("." , builtin_source, "Run commands in a file"), + BLTIN(":" , builtin_true, "No-op"), + BLTIN("[" , builtin_test, "Test condition"), + BLTIN("[[" , builtin_test, "Test condition"), +#if ENABLE_HUSH_JOB + BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"), +#endif +#if ENABLE_HUSH_LOOPS + BLTIN("break" , builtin_break, "Exit from a loop"), +#endif + BLTIN("cd" , builtin_cd, "Change directory"), +#if ENABLE_HUSH_LOOPS + BLTIN("continue", builtin_continue, "Start new loop iteration"), +#endif + BLTIN("echo" , builtin_echo, "Write to stdout"), + BLTIN("eval" , builtin_eval, "Construct and run shell command"), + BLTIN("exec" , builtin_exec, "Execute command, don't return to shell"), + BLTIN("exit" , builtin_exit, "Exit"), + BLTIN("export", builtin_export, "Set environment variable"), +#if ENABLE_HUSH_JOB + BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"), + BLTIN("jobs" , builtin_jobs, "List active jobs"), +#endif + BLTIN("pwd" , builtin_pwd, "Print current directory"), + BLTIN("read" , builtin_read, "Input environment variable"), +// BLTIN("return", builtin_not_written, "Return from a function"), + BLTIN("set" , builtin_set, "Set/unset shell local variables"), + BLTIN("shift" , builtin_shift, "Shift positional parameters"), +// BLTIN("trap" , builtin_not_written, "Trap signals"), + BLTIN("test" , builtin_test, "Test condition"), +// BLTIN("ulimit", builtin_not_written, "Control resource limits"), + BLTIN("umask" , builtin_umask, "Set file creation mask"), + BLTIN("unset" , builtin_unset, "Unset environment variable"), +#if ENABLE_HUSH_HELP + BLTIN("help" , builtin_help, "List shell built-in commands"), +#endif +}; + + +/* Signals are grouped, we handle them in batches */ +static void set_misc_sighandler(void (*handler)(int)) +{ + bb_signals(0 + + (1 << SIGINT) + + (1 << SIGQUIT) + + (1 << SIGTERM) + , handler); +} + +#if ENABLE_HUSH_JOB + +static void set_fatal_sighandler(void (*handler)(int)) +{ + bb_signals(0 + + (1 << SIGILL) + + (1 << SIGTRAP) + + (1 << SIGABRT) + + (1 << SIGFPE) + + (1 << SIGBUS) + + (1 << SIGSEGV) + /* bash 3.2 seems to handle these just like 'fatal' ones */ + + (1 << SIGHUP) + + (1 << SIGPIPE) + + (1 << SIGALRM) + , handler); +} +static void set_jobctrl_sighandler(void (*handler)(int)) +{ + bb_signals(0 + + (1 << SIGTSTP) + + (1 << SIGTTIN) + + (1 << SIGTTOU) + , handler); +} +/* SIGCHLD is special and handled separately */ + +static void set_every_sighandler(void (*handler)(int)) +{ + set_fatal_sighandler(handler); + set_jobctrl_sighandler(handler); + set_misc_sighandler(handler); + signal(SIGCHLD, handler); +} + +static void handler_ctrl_c(int sig UNUSED_PARAM) +{ + debug_printf_jobs("got sig %d\n", sig); +// as usual we can have all kinds of nasty problems with leaked malloc data here + siglongjmp(G.toplevel_jb, 1); +} + +static void handler_ctrl_z(int sig UNUSED_PARAM) +{ + pid_t pid; + + debug_printf_jobs("got tty sig %d in pid %d\n", sig, getpid()); + pid = fork(); + if (pid < 0) /* can't fork. Pretend there was no ctrl-Z */ + return; + G.ctrl_z_flag = 1; + if (!pid) { /* child */ + if (ENABLE_HUSH_JOB) + die_sleep = 0; /* let nofork's xfuncs die */ + bb_setpgrp(); + debug_printf_jobs("set pgrp for child %d ok\n", getpid()); + set_every_sighandler(SIG_DFL); + raise(SIGTSTP); /* resend TSTP so that child will be stopped */ + debug_printf_jobs("returning in child\n"); + /* return to nofork, it will eventually exit now, + * not return back to shell */ + return; + } + /* parent */ + /* finish filling up pipe info */ + G.toplevel_list->pgrp = pid; /* child is in its own pgrp */ + G.toplevel_list->cmds[0].pid = pid; + /* parent needs to longjmp out of running nofork. + * we will "return" exitcode 0, with child put in background */ +// as usual we can have all kinds of nasty problems with leaked malloc data here + debug_printf_jobs("siglongjmp in parent\n"); + siglongjmp(G.toplevel_jb, 1); +} + +/* Restores tty foreground process group, and exits. + * May be called as signal handler for fatal signal + * (will faithfully resend signal to itself, producing correct exit state) + * or called directly with -EXITCODE. + * We also call it if xfunc is exiting. */ +static void sigexit(int sig) NORETURN; +static void sigexit(int sig) +{ + /* Disable all signals: job control, SIGPIPE, etc. */ + sigprocmask_allsigs(SIG_BLOCK); + +#if ENABLE_HUSH_INTERACTIVE + if (G.interactive_fd) + tcsetpgrp(G.interactive_fd, G.saved_tty_pgrp); +#endif + + /* Not a signal, just exit */ + if (sig <= 0) + _exit(- sig); + + kill_myself_with_sig(sig); /* does not return */ +} + +/* Restores tty foreground process group, and exits. */ +static void hush_exit(int exitcode) NORETURN; +static void hush_exit(int exitcode) +{ + fflush(NULL); /* flush all streams */ + sigexit(- (exitcode & 0xff)); +} + +#else /* !JOB */ + +#define set_fatal_sighandler(handler) ((void)0) +#define set_jobctrl_sighandler(handler) ((void)0) +#define hush_exit(e) exit(e) + +#endif /* JOB */ + + +static const char *set_cwd(void) +{ + if (G.cwd == bb_msg_unknown) + G.cwd = NULL; /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */ + G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd); + if (!G.cwd) + G.cwd = bb_msg_unknown; + return G.cwd; +} + + +/* + * o_string support + */ +#define B_CHUNK (32 * sizeof(char*)) + +static void o_reset(o_string *o) +{ + o->length = 0; + o->nonnull = 0; + if (o->data) + o->data[0] = '\0'; +} + +static void o_free(o_string *o) +{ + free(o->data); + memset(o, 0, sizeof(*o)); +} + +static void o_grow_by(o_string *o, int len) +{ + if (o->length + len > o->maxlen) { + o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK); + o->data = xrealloc(o->data, 1 + o->maxlen); + } +} + +static void o_addchr(o_string *o, int ch) +{ + debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o); + o_grow_by(o, 1); + o->data[o->length] = ch; + o->length++; + o->data[o->length] = '\0'; +} + +static void o_addstr(o_string *o, const char *str, int len) +{ + o_grow_by(o, len); + memcpy(&o->data[o->length], str, len); + o->length += len; + o->data[o->length] = '\0'; +} + +static void o_addstr_duplicate_backslash(o_string *o, const char *str, int len) +{ + while (len) { + o_addchr(o, *str); + if (*str++ == '\\' + && (*str != '*' && *str != '?' && *str != '[') + ) { + o_addchr(o, '\\'); + } + len--; + } +} + +/* My analysis of quoting semantics tells me that state information + * is associated with a destination, not a source. + */ +static void o_addqchr(o_string *o, int ch) +{ + int sz = 1; + char *found = strchr("*?[\\", ch); + if (found) + sz++; + o_grow_by(o, sz); + if (found) { + o->data[o->length] = '\\'; + o->length++; + } + o->data[o->length] = ch; + o->length++; + o->data[o->length] = '\0'; +} + +static void o_addQchr(o_string *o, int ch) +{ + int sz = 1; + if (o->o_quote && strchr("*?[\\", ch)) { + sz++; + o->data[o->length] = '\\'; + o->length++; + } + o_grow_by(o, sz); + o->data[o->length] = ch; + o->length++; + o->data[o->length] = '\0'; +} + +static void o_addQstr(o_string *o, const char *str, int len) +{ + if (!o->o_quote) { + o_addstr(o, str, len); + return; + } + while (len) { + char ch; + int sz; + int ordinary_cnt = strcspn(str, "*?[\\"); + if (ordinary_cnt > len) /* paranoia */ + ordinary_cnt = len; + o_addstr(o, str, ordinary_cnt); + if (ordinary_cnt == len) + return; + str += ordinary_cnt; + len -= ordinary_cnt + 1; /* we are processing + 1 char below */ + + ch = *str++; + sz = 1; + if (ch) { /* it is necessarily one of "*?[\\" */ + sz++; + o->data[o->length] = '\\'; + o->length++; + } + o_grow_by(o, sz); + o->data[o->length] = ch; + o->length++; + o->data[o->length] = '\0'; + } +} + +/* A special kind of o_string for $VAR and `cmd` expansion. + * It contains char* list[] at the beginning, which is grown in 16 element + * increments. Actual string data starts at the next multiple of 16 * (char*). + * list[i] contains an INDEX (int!) into this string data. + * It means that if list[] needs to grow, data needs to be moved higher up + * but list[i]'s need not be modified. + * NB: remembering how many list[i]'s you have there is crucial. + * o_finalize_list() operation post-processes this structure - calculates + * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well. + */ +#if DEBUG_EXPAND || DEBUG_GLOB +static void debug_print_list(const char *prefix, o_string *o, int n) +{ + char **list = (char**)o->data; + int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); + int i = 0; + fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n", + prefix, list, n, string_start, o->length, o->maxlen); + while (i < n) { + fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i], + o->data + (int)list[i] + string_start, + o->data + (int)list[i] + string_start); + i++; + } + if (n) { + const char *p = o->data + (int)list[n - 1] + string_start; + fprintf(stderr, " total_sz:%d\n", (p + strlen(p) + 1) - o->data); + } +} +#else +#define debug_print_list(prefix, o, n) ((void)0) +#endif + +/* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value + * in list[n] so that it points past last stored byte so far. + * It returns n+1. */ +static int o_save_ptr_helper(o_string *o, int n) +{ + char **list = (char**)o->data; + int string_start; + int string_len; + + if (!o->has_empty_slot) { + string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); + string_len = o->length - string_start; + if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */ + debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start); + /* list[n] points to string_start, make space for 16 more pointers */ + o->maxlen += 0x10 * sizeof(list[0]); + o->data = xrealloc(o->data, o->maxlen + 1); + list = (char**)o->data; + memmove(list + n + 0x10, list + n, string_len); + o->length += 0x10 * sizeof(list[0]); + } else + debug_printf_list("list[%d]=%d string_start=%d\n", n, string_len, string_start); + } else { + /* We have empty slot at list[n], reuse without growth */ + string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */ + string_len = o->length - string_start; + debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n", n, string_len, string_start); + o->has_empty_slot = 0; + } + list[n] = (char*)(ptrdiff_t)string_len; + return n + 1; +} + +/* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */ +static int o_get_last_ptr(o_string *o, int n) +{ + char **list = (char**)o->data; + int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); + + return ((int)(ptrdiff_t)list[n-1]) + string_start; +} + +/* o_glob performs globbing on last list[], saving each result + * as a new list[]. */ +static int o_glob(o_string *o, int n) +{ + glob_t globdata; + int gr; + char *pattern; + + debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data); + if (!o->data) + return o_save_ptr_helper(o, n); + pattern = o->data + o_get_last_ptr(o, n); + debug_printf_glob("glob pattern '%s'\n", pattern); + if (!glob_needed(pattern)) { + literal: + o->length = unbackslash(pattern) - o->data; + debug_printf_glob("glob pattern '%s' is literal\n", pattern); + return o_save_ptr_helper(o, n); + } + + memset(&globdata, 0, sizeof(globdata)); + gr = glob(pattern, 0, NULL, &globdata); + debug_printf_glob("glob('%s'):%d\n", pattern, gr); + if (gr == GLOB_NOSPACE) + bb_error_msg_and_die("out of memory during glob"); + if (gr == GLOB_NOMATCH) { + globfree(&globdata); + goto literal; + } + if (gr != 0) { /* GLOB_ABORTED ? */ +//TODO: testcase for bad glob pattern behavior + bb_error_msg("glob(3) error %d on '%s'", gr, pattern); + } + if (globdata.gl_pathv && globdata.gl_pathv[0]) { + char **argv = globdata.gl_pathv; + o->length = pattern - o->data; /* "forget" pattern */ + while (1) { + o_addstr(o, *argv, strlen(*argv) + 1); + n = o_save_ptr_helper(o, n); + argv++; + if (!*argv) + break; + } + } + globfree(&globdata); + if (DEBUG_GLOB) + debug_print_list("o_glob returning", o, n); + return n; +} + +/* If o->o_glob == 1, glob the string so far remembered. + * Otherwise, just finish current list[] and start new */ +static int o_save_ptr(o_string *o, int n) +{ + if (o->o_glob) + return o_glob(o, n); /* o_save_ptr_helper is inside */ + return o_save_ptr_helper(o, n); +} + +/* "Please convert list[n] to real char* ptrs, and NULL terminate it." */ +static char **o_finalize_list(o_string *o, int n) +{ + char **list; + int string_start; + + n = o_save_ptr(o, n); /* force growth for list[n] if necessary */ + if (DEBUG_EXPAND) + debug_print_list("finalized", o, n); + debug_printf_expand("finalized n:%d\n", n); + list = (char**)o->data; + string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); + list[--n] = NULL; + while (n) { + n--; + list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start; + } + return list; +} + + +/* + * in_str support + */ +static int static_get(struct in_str *i) +{ + int ch = *i->p++; + if (ch == '\0') return EOF; + return ch; +} + +static int static_peek(struct in_str *i) +{ + return *i->p; +} + +#if ENABLE_HUSH_INTERACTIVE + +#if ENABLE_FEATURE_EDITING +static void cmdedit_set_initial_prompt(void) +{ +#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT + G.PS1 = NULL; +#else + G.PS1 = getenv("PS1"); + if (G.PS1 == NULL) + G.PS1 = "\\w \\$ "; +#endif +} +#endif /* EDITING */ + +static const char* setup_prompt_string(int promptmode) +{ + const char *prompt_str; + debug_printf("setup_prompt_string %d ", promptmode); +#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT + /* Set up the prompt */ + if (promptmode == 0) { /* PS1 */ + free((char*)G.PS1); + G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#'); + prompt_str = G.PS1; + } else { + prompt_str = G.PS2; + } +#else + prompt_str = (promptmode == 0) ? G.PS1 : G.PS2; +#endif + debug_printf("result '%s'\n", prompt_str); + return prompt_str; +} + +static void get_user_input(struct in_str *i) +{ + int r; + const char *prompt_str; + + prompt_str = setup_prompt_string(i->promptmode); +#if ENABLE_FEATURE_EDITING + /* Enable command line editing only while a command line + * is actually being read */ + do { + r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state); + } while (r == 0); /* repeat if Ctrl-C */ + i->eof_flag = (r < 0); + if (i->eof_flag) { /* EOF/error detected */ + G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */ + G.user_input_buf[1] = '\0'; + } +#else + fputs(prompt_str, stdout); + fflush(stdout); + G.user_input_buf[0] = r = fgetc(i->file); + /*G.user_input_buf[1] = '\0'; - already is and never changed */ + i->eof_flag = (r == EOF); +#endif + i->p = G.user_input_buf; +} + +#endif /* INTERACTIVE */ + +/* This is the magic location that prints prompts + * and gets data back from the user */ +static int file_get(struct in_str *i) +{ + int ch; + + /* If there is data waiting, eat it up */ + if (i->p && *i->p) { +#if ENABLE_HUSH_INTERACTIVE + take_cached: +#endif + ch = *i->p++; + if (i->eof_flag && !*i->p) + ch = EOF; + } else { + /* need to double check i->file because we might be doing something + * more complicated by now, like sourcing or substituting. */ +#if ENABLE_HUSH_INTERACTIVE + if (G.interactive_fd && i->promptme && i->file == stdin) { + do { + get_user_input(i); + } while (!*i->p); /* need non-empty line */ + i->promptmode = 1; /* PS2 */ + i->promptme = 0; + goto take_cached; + } +#endif + ch = fgetc(i->file); + } + debug_printf("file_get: got a '%c' %d\n", ch, ch); +#if ENABLE_HUSH_INTERACTIVE + if (ch == '\n') + i->promptme = 1; +#endif + return ch; +} + +/* All the callers guarantee this routine will never be + * used right after a newline, so prompting is not needed. + */ +static int file_peek(struct in_str *i) +{ + int ch; + if (i->p && *i->p) { + if (i->eof_flag && !i->p[1]) + return EOF; + return *i->p; + } + ch = fgetc(i->file); + i->eof_flag = (ch == EOF); + i->peek_buf[0] = ch; + i->peek_buf[1] = '\0'; + i->p = i->peek_buf; + debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p); + return ch; +} + +static void setup_file_in_str(struct in_str *i, FILE *f) +{ + i->peek = file_peek; + i->get = file_get; +#if ENABLE_HUSH_INTERACTIVE + i->promptme = 1; + i->promptmode = 0; /* PS1 */ +#endif + i->file = f; + i->p = NULL; +} + +static void setup_string_in_str(struct in_str *i, const char *s) +{ + i->peek = static_peek; + i->get = static_get; +#if ENABLE_HUSH_INTERACTIVE + i->promptme = 1; + i->promptmode = 0; /* PS1 */ +#endif + i->p = s; + i->eof_flag = 0; +} + + +/* squirrel != NULL means we squirrel away copies of stdin, stdout, + * and stderr if they are redirected. */ +static int setup_redirects(struct command *prog, int squirrel[]) +{ + int openfd, mode; + struct redir_struct *redir; + + for (redir = prog->redirects; redir; redir = redir->next) { + if (redir->dup == -1 && redir->rd_filename == NULL) { + /* something went wrong in the parse. Pretend it didn't happen */ + continue; + } + if (redir->dup == -1) { + char *p; + mode = redir_table[redir->rd_type].mode; +//TODO: check redir for names like '\\' + p = expand_string_to_string(redir->rd_filename); + openfd = open_or_warn(p, mode); + free(p); + if (openfd < 0) { + /* this could get lost if stderr has been redirected, but + bash and ash both lose it as well (though zsh doesn't!) */ + return 1; + } + } else { + openfd = redir->dup; + } + + if (openfd != redir->fd) { + if (squirrel && redir->fd < 3) { + squirrel[redir->fd] = dup(redir->fd); + } + if (openfd == -3) { + //close(openfd); // close(-3) ??! + } else { + dup2(openfd, redir->fd); + if (redir->dup == -1) + close(openfd); + } + } + } + return 0; +} + +static void restore_redirects(int squirrel[]) +{ + int i, fd; + for (i = 0; i < 3; i++) { + fd = squirrel[i]; + if (fd != -1) { + /* We simply die on error */ + xmove_fd(fd, i); + } + } +} + +static char **expand_assignments(char **argv, int count) +{ + int i; + char **p = NULL; + /* Expand assignments into one string each */ + for (i = 0; i < count; i++) { + p = add_string_to_strings(p, expand_string_to_string(argv[i])); + } + return p; +} + +/* Called after [v]fork() in run_pipe(), or from builtin_exec(). + * Never returns. + * XXX no exit() here. If you don't exec, use _exit instead. + * The at_exit handlers apparently confuse the calling process, + * in particular stdin handling. Not sure why? -- because of vfork! (vda) */ +static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded) +{ + int rcode; + char **new_env; + const struct built_in_command *x; + + /* If a variable is assigned in a forest, and nobody listens, + * was it ever really set? + */ + if (!argv[assignment_cnt]) + _exit(EXIT_SUCCESS); + + new_env = expand_assignments(argv, assignment_cnt); +#if BB_MMU + putenv_all(new_env); + free(new_env); /* optional */ +#else + nommu_save->new_env = new_env; + nommu_save->old_env = putenv_all_and_save_old(new_env); +#endif + if (argv_expanded) { + argv = argv_expanded; + } else { + argv = expand_strvec_to_strvec(argv); +#if !BB_MMU + nommu_save->argv = argv; +#endif + } + + /* + * Check if the command matches any of the builtins. + * Depending on context, this might be redundant. But it's + * easier to waste a few CPU cycles than it is to figure out + * if this is one of those cases. + */ + for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) { + if (strcmp(argv[0], x->cmd) == 0) { + debug_printf_exec("running builtin '%s'\n", argv[0]); + rcode = x->function(argv); + fflush(stdout); + _exit(rcode); + } + } + + /* Check if the command matches any busybox applets */ +#if ENABLE_FEATURE_SH_STANDALONE + if (strchr(argv[0], '/') == NULL) { + int a = find_applet_by_name(argv[0]); + if (a >= 0) { + if (APPLET_IS_NOEXEC(a)) { + debug_printf_exec("running applet '%s'\n", argv[0]); +// is it ok that run_applet_no_and_exit() does exit(), not _exit()? + run_applet_no_and_exit(a, argv); + } + /* re-exec ourselves with the new arguments */ + debug_printf_exec("re-execing applet '%s'\n", argv[0]); + execvp(bb_busybox_exec_path, argv); + /* If they called chroot or otherwise made the binary no longer + * executable, fall through */ + } + } +#endif + + debug_printf_exec("execing '%s'\n", argv[0]); + execvp(argv[0], argv); + bb_perror_msg("can't exec '%s'", argv[0]); + _exit(EXIT_FAILURE); +} + +/* Called after [v]fork() in run_pipe() + */ +static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded) +{ + if (command->argv) + pseudo_exec_argv(nommu_save, command->argv, command->assignment_cnt, argv_expanded); + + if (command->group) { +#if !BB_MMU + bb_error_msg_and_die("nested lists are not supported on NOMMU"); +#else + int rcode; + debug_printf_exec("pseudo_exec: run_list\n"); + rcode = run_list(command->group); + /* OK to leak memory by not calling free_pipe_list, + * since this process is about to exit */ + _exit(rcode); +#endif + } + + /* Can happen. See what bash does with ">foo" by itself. */ + debug_printf("trying to pseudo_exec null command\n"); + _exit(EXIT_SUCCESS); +} + +#if ENABLE_HUSH_JOB +static const char *get_cmdtext(struct pipe *pi) +{ + char **argv; + char *p; + int len; + + /* This is subtle. ->cmdtext is created only on first backgrounding. + * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...) + * On subsequent bg argv is trashed, but we won't use it */ + if (pi->cmdtext) + return pi->cmdtext; + argv = pi->cmds[0].argv; + if (!argv || !argv[0]) { + pi->cmdtext = xzalloc(1); + return pi->cmdtext; + } + + len = 0; + do len += strlen(*argv) + 1; while (*++argv); + pi->cmdtext = p = xmalloc(len); + argv = pi->cmds[0].argv; + do { + len = strlen(*argv); + memcpy(p, *argv, len); + p += len; + *p++ = ' '; + } while (*++argv); + p[-1] = '\0'; + return pi->cmdtext; +} + +static void insert_bg_job(struct pipe *pi) +{ + struct pipe *thejob; + int i; + + /* Linear search for the ID of the job to use */ + pi->jobid = 1; + for (thejob = G.job_list; thejob; thejob = thejob->next) + if (thejob->jobid >= pi->jobid) + pi->jobid = thejob->jobid + 1; + + /* Add thejob to the list of running jobs */ + if (!G.job_list) { + thejob = G.job_list = xmalloc(sizeof(*thejob)); + } else { + for (thejob = G.job_list; thejob->next; thejob = thejob->next) + continue; + thejob->next = xmalloc(sizeof(*thejob)); + thejob = thejob->next; + } + + /* Physically copy the struct job */ + memcpy(thejob, pi, sizeof(struct pipe)); + thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds); + /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */ + for (i = 0; i < pi->num_cmds; i++) { +// TODO: do we really need to have so many fields which are just dead weight +// at execution stage? + thejob->cmds[i].pid = pi->cmds[i].pid; + /* all other fields are not used and stay zero */ + } + thejob->next = NULL; + thejob->cmdtext = xstrdup(get_cmdtext(pi)); + + /* We don't wait for background thejobs to return -- append it + to the list of backgrounded thejobs and leave it alone */ + printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext); + G.last_bg_pid = thejob->cmds[0].pid; + G.last_jobid = thejob->jobid; +} + +static void remove_bg_job(struct pipe *pi) +{ + struct pipe *prev_pipe; + + if (pi == G.job_list) { + G.job_list = pi->next; + } else { + prev_pipe = G.job_list; + while (prev_pipe->next != pi) + prev_pipe = prev_pipe->next; + prev_pipe->next = pi->next; + } + if (G.job_list) + G.last_jobid = G.job_list->jobid; + else + G.last_jobid = 0; +} + +/* Remove a backgrounded job */ +static void delete_finished_bg_job(struct pipe *pi) +{ + remove_bg_job(pi); + pi->stopped_cmds = 0; + free_pipe(pi, 0); + free(pi); +} +#endif /* JOB */ + +/* Check to see if any processes have exited -- if they + * have, figure out why and see if a job has completed */ +static int checkjobs(struct pipe* fg_pipe) +{ + int attributes; + int status; +#if ENABLE_HUSH_JOB + struct pipe *pi; +#endif + pid_t childpid; + int rcode = 0; + + attributes = WUNTRACED; + if (fg_pipe == NULL) + attributes |= WNOHANG; + +/* Do we do this right? + * bash-3.00# sleep 20 | false + * <ctrl-Z pressed> + * [3]+ Stopped sleep 20 | false + * bash-3.00# echo $? + * 1 <========== bg pipe is not fully done, but exitcode is already known! + */ + +//FIXME: non-interactive bash does not continue even if all processes in fg pipe +//are stopped. Testcase: "cat | cat" in a script (not on command line) +// + killall -STOP cat + + wait_more: +// TODO: safe_waitpid? + while ((childpid = waitpid(-1, &status, attributes)) > 0) { + int i; + const int dead = WIFEXITED(status) || WIFSIGNALED(status); +#if DEBUG_JOBS + if (WIFSTOPPED(status)) + debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n", + childpid, WSTOPSIG(status), WEXITSTATUS(status)); + if (WIFSIGNALED(status)) + debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n", + childpid, WTERMSIG(status), WEXITSTATUS(status)); + if (WIFEXITED(status)) + debug_printf_jobs("pid %d exited, exitcode %d\n", + childpid, WEXITSTATUS(status)); +#endif + /* Were we asked to wait for fg pipe? */ + if (fg_pipe) { + for (i = 0; i < fg_pipe->num_cmds; i++) { + debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid); + if (fg_pipe->cmds[i].pid != childpid) + continue; + /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */ + if (dead) { + fg_pipe->cmds[i].pid = 0; + fg_pipe->alive_cmds--; + if (i == fg_pipe->num_cmds - 1) { + /* last process gives overall exitstatus */ + rcode = WEXITSTATUS(status); + IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;) + } + } else { + fg_pipe->cmds[i].is_stopped = 1; + fg_pipe->stopped_cmds++; + } + debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n", + fg_pipe->alive_cmds, fg_pipe->stopped_cmds); + if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) { + /* All processes in fg pipe have exited/stopped */ +#if ENABLE_HUSH_JOB + if (fg_pipe->alive_cmds) + insert_bg_job(fg_pipe); +#endif + return rcode; + } + /* There are still running processes in the fg pipe */ + goto wait_more; /* do waitpid again */ + } + /* it wasnt fg_pipe, look for process in bg pipes */ + } + +#if ENABLE_HUSH_JOB + /* We asked to wait for bg or orphaned children */ + /* No need to remember exitcode in this case */ + for (pi = G.job_list; pi; pi = pi->next) { + for (i = 0; i < pi->num_cmds; i++) { + if (pi->cmds[i].pid == childpid) + goto found_pi_and_prognum; + } + } + /* Happens when shell is used as init process (init=/bin/sh) */ + debug_printf("checkjobs: pid %d was not in our list!\n", childpid); + continue; /* do waitpid again */ + + found_pi_and_prognum: + if (dead) { + /* child exited */ + pi->cmds[i].pid = 0; + pi->alive_cmds--; + if (!pi->alive_cmds) { + printf(JOB_STATUS_FORMAT, pi->jobid, + "Done", pi->cmdtext); + delete_finished_bg_job(pi); + } + } else { + /* child stopped */ + pi->cmds[i].is_stopped = 1; + pi->stopped_cmds++; + } +#endif + } /* while (waitpid succeeds)... */ + + /* wait found no children or failed */ + + if (childpid && errno != ECHILD) + bb_perror_msg("waitpid"); + return rcode; +} + +#if ENABLE_HUSH_JOB +static int checkjobs_and_fg_shell(struct pipe* fg_pipe) +{ + pid_t p; + int rcode = checkjobs(fg_pipe); + /* Job finished, move the shell to the foreground */ + p = getpgid(0); /* pgid of our process */ + debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p); + tcsetpgrp(G.interactive_fd, p); + return rcode; +} +#endif + +/* run_pipe() starts all the jobs, but doesn't wait for anything + * to finish. See checkjobs(). + * + * return code is normally -1, when the caller has to wait for children + * to finish to determine the exit status of the pipe. If the pipe + * is a simple builtin command, however, the action is done by the + * time run_pipe returns, and the exit code is provided as the + * return value. + * + * The input of the pipe is always stdin, the output is always + * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus, + * because it tries to avoid running the command substitution in + * subshell, when that is in fact necessary. The subshell process + * now has its stdout directed to the input of the appropriate pipe, + * so this routine is noticeably simpler. + * + * Returns -1 only if started some children. IOW: we have to + * mask out retvals of builtins etc with 0xff! + */ +static int run_pipe(struct pipe *pi) +{ + int i; + int nextin; + int pipefds[2]; /* pipefds[0] is for reading */ + struct command *command; + char **argv_expanded; + char **argv; + const struct built_in_command *x; + char *p; + /* it is not always needed, but we aim to smaller code */ + int squirrel[] = { -1, -1, -1 }; + int rcode; + const int single_and_fg = (pi->num_cmds == 1 && pi->followup != PIPE_BG); + + debug_printf_exec("run_pipe start: single_and_fg=%d\n", single_and_fg); + +#if ENABLE_HUSH_JOB + pi->pgrp = -1; +#endif + pi->alive_cmds = 1; + pi->stopped_cmds = 0; + + /* Check if this is a simple builtin (not part of a pipe). + * Builtins within pipes have to fork anyway, and are handled in + * pseudo_exec. "echo foo | read bar" doesn't work on bash, either. + */ + command = &(pi->cmds[0]); + +#if ENABLE_HUSH_FUNCTIONS + if (single_and_fg && command->group && command->grp_type == GRP_FUNCTION) { + /* We "execute" function definition */ + bb_error_msg("here we ought to remember function definition, and go on"); + return EXIT_SUCCESS; + } +#endif + + if (single_and_fg && command->group && command->grp_type == GRP_NORMAL) { + debug_printf("non-subshell grouping\n"); + setup_redirects(command, squirrel); + debug_printf_exec(": run_list\n"); + rcode = run_list(command->group) & 0xff; + restore_redirects(squirrel); + debug_printf_exec("run_pipe return %d\n", rcode); + IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;) + return rcode; + } + + argv = command->argv; + argv_expanded = NULL; + + if (single_and_fg && argv != NULL) { + char **new_env = NULL; + char **old_env = NULL; + + i = command->assignment_cnt; + if (i != 0 && argv[i] == NULL) { + /* assignments, but no command: set local environment */ + for (i = 0; argv[i] != NULL; i++) { + debug_printf("local environment set: %s\n", argv[i]); + p = expand_string_to_string(argv[i]); + set_local_var(p, 0); + } + return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */ + } + + /* Expand the rest into (possibly) many strings each */ + argv_expanded = expand_strvec_to_strvec(argv + i); + + for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) { + if (strcmp(argv_expanded[0], x->cmd) != 0) + continue; + if (x->function == builtin_exec && argv_expanded[1] == NULL) { + debug_printf("exec with redirects only\n"); + setup_redirects(command, NULL); + rcode = EXIT_SUCCESS; + goto clean_up_and_ret1; + } + debug_printf("builtin inline %s\n", argv_expanded[0]); + /* XXX setup_redirects acts on file descriptors, not FILEs. + * This is perfect for work that comes after exec(). + * Is it really safe for inline use? Experimentally, + * things seem to work with glibc. */ + setup_redirects(command, squirrel); + new_env = expand_assignments(argv, command->assignment_cnt); + old_env = putenv_all_and_save_old(new_env); + debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv_expanded[1]); + rcode = x->function(argv_expanded) & 0xff; +#if ENABLE_FEATURE_SH_STANDALONE + clean_up_and_ret: +#endif + restore_redirects(squirrel); + free_strings_and_unsetenv(new_env, 1); + putenv_all(old_env); + free(old_env); /* not free_strings()! */ + clean_up_and_ret1: + free(argv_expanded); + IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;) + debug_printf_exec("run_pipe return %d\n", rcode); + return rcode; + } +#if ENABLE_FEATURE_SH_STANDALONE + i = find_applet_by_name(argv_expanded[0]); + if (i >= 0 && APPLET_IS_NOFORK(i)) { + setup_redirects(command, squirrel); + save_nofork_data(&G.nofork_save); + new_env = expand_assignments(argv, command->assignment_cnt); + old_env = putenv_all_and_save_old(new_env); + debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]); + rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded); + goto clean_up_and_ret; + } +#endif + } + + /* NB: argv_expanded may already be created, and that + * might include `cmd` runs! Do not rerun it! We *must* + * use argv_expanded if it's non-NULL */ + + /* Disable job control signals for shell (parent) and + * for initial child code after fork */ + set_jobctrl_sighandler(SIG_IGN); + + /* Going to fork a child per each pipe member */ + pi->alive_cmds = 0; + nextin = 0; + + for (i = 0; i < pi->num_cmds; i++) { +#if !BB_MMU + volatile nommu_save_t nommu_save; + nommu_save.new_env = NULL; + nommu_save.old_env = NULL; + nommu_save.argv = NULL; +#endif + command = &(pi->cmds[i]); + if (command->argv) { + debug_printf_exec(": pipe member '%s' '%s'...\n", command->argv[0], command->argv[1]); + } else + debug_printf_exec(": pipe member with no argv\n"); + + /* pipes are inserted between pairs of commands */ + pipefds[0] = 0; + pipefds[1] = 1; + if ((i + 1) < pi->num_cmds) + xpipe(pipefds); + + command->pid = BB_MMU ? fork() : vfork(); + if (!command->pid) { /* child */ + if (ENABLE_HUSH_JOB) + die_sleep = 0; /* let nofork's xfuncs die */ +#if ENABLE_HUSH_JOB + /* Every child adds itself to new process group + * with pgid == pid_of_first_child_in_pipe */ + if (G.run_list_level == 1 && G.interactive_fd) { + pid_t pgrp; + /* Don't do pgrp restore anymore on fatal signals */ + set_fatal_sighandler(SIG_DFL); + pgrp = pi->pgrp; + if (pgrp < 0) /* true for 1st process only */ + pgrp = getpid(); + if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) { + /* We do it in *every* child, not just first, + * to avoid races */ + tcsetpgrp(G.interactive_fd, pgrp); + } + } +#endif + xmove_fd(nextin, 0); + xmove_fd(pipefds[1], 1); /* write end */ + if (pipefds[0] > 1) + close(pipefds[0]); /* read end */ + /* Like bash, explicit redirects override pipes, + * and the pipe fd is available for dup'ing. */ + setup_redirects(command, NULL); + + /* Restore default handlers just prior to exec */ + set_jobctrl_sighandler(SIG_DFL); + set_misc_sighandler(SIG_DFL); + signal(SIGCHLD, SIG_DFL); + /* Stores to nommu_save list of env vars putenv'ed + * (NOMMU, on MMU we don't need that) */ + /* cast away volatility... */ + pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded); + /* pseudo_exec() does not return */ + } + /* parent */ +#if !BB_MMU + /* Clean up after vforked child */ + free(nommu_save.argv); + free_strings_and_unsetenv(nommu_save.new_env, 1); + putenv_all(nommu_save.old_env); +#endif + free(argv_expanded); + argv_expanded = NULL; + if (command->pid < 0) { /* [v]fork failed */ + /* Clearly indicate, was it fork or vfork */ + bb_perror_msg(BB_MMU ? "fork" : "vfork"); + } else { + pi->alive_cmds++; +#if ENABLE_HUSH_JOB + /* Second and next children need to know pid of first one */ + if (pi->pgrp < 0) + pi->pgrp = command->pid; +#endif + } + + if (i) + close(nextin); + if ((i + 1) < pi->num_cmds) + close(pipefds[1]); /* write end */ + /* Pass read (output) pipe end to next iteration */ + nextin = pipefds[0]; + } + + if (!pi->alive_cmds) { + debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n"); + return 1; + } + + debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds); + return -1; +} + +#ifndef debug_print_tree +static void debug_print_tree(struct pipe *pi, int lvl) +{ + static const char *const PIPE[] = { + [PIPE_SEQ] = "SEQ", + [PIPE_AND] = "AND", + [PIPE_OR ] = "OR" , + [PIPE_BG ] = "BG" , + }; + static const char *RES[] = { + [RES_NONE ] = "NONE" , +#if ENABLE_HUSH_IF + [RES_IF ] = "IF" , + [RES_THEN ] = "THEN" , + [RES_ELIF ] = "ELIF" , + [RES_ELSE ] = "ELSE" , + [RES_FI ] = "FI" , +#endif +#if ENABLE_HUSH_LOOPS + [RES_FOR ] = "FOR" , + [RES_WHILE] = "WHILE", + [RES_UNTIL] = "UNTIL", + [RES_DO ] = "DO" , + [RES_DONE ] = "DONE" , +#endif +#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE + [RES_IN ] = "IN" , +#endif +#if ENABLE_HUSH_CASE + [RES_CASE ] = "CASE" , + [RES_MATCH] = "MATCH", + [RES_CASEI] = "CASEI", + [RES_ESAC ] = "ESAC" , +#endif + [RES_XXXX ] = "XXXX" , + [RES_SNTX ] = "SNTX" , + }; + static const char *const GRPTYPE[] = { + "()", + "{}", +#if ENABLE_HUSH_FUNCTIONS + "func()", +#endif + }; + + int pin, prn; + + pin = 0; + while (pi) { + fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "", + pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]); + prn = 0; + while (prn < pi->num_cmds) { + struct command *command = &pi->cmds[prn]; + char **argv = command->argv; + + fprintf(stderr, "%*s prog %d assignment_cnt:%d", lvl*2, "", prn, command->assignment_cnt); + if (command->group) { + fprintf(stderr, " group %s: (argv=%p)\n", + GRPTYPE[command->grp_type], + argv); + debug_print_tree(command->group, lvl+1); + prn++; + continue; + } + if (argv) while (*argv) { + fprintf(stderr, " '%s'", *argv); + argv++; + } + fprintf(stderr, "\n"); + prn++; + } + pi = pi->next; + pin++; + } +} +#endif + +/* NB: called by pseudo_exec, and therefore must not modify any + * global data until exec/_exit (we can be a child after vfork!) */ +static int run_list(struct pipe *pi) +{ +#if ENABLE_HUSH_CASE + char *case_word = NULL; +#endif +#if ENABLE_HUSH_LOOPS + struct pipe *loop_top = NULL; + char *for_varname = NULL; + char **for_lcur = NULL; + char **for_list = NULL; +#endif + smallint flag_skip = 1; + smalluint rcode = 0; /* probably just for compiler */ +#if ENABLE_HUSH_IF || ENABLE_HUSH_CASE + smalluint cond_code = 0; +#else + enum { cond_code = 0, }; +#endif + /*enum reserved_style*/ smallint rword = RES_NONE; + /*enum reserved_style*/ smallint skip_more_for_this_rword = RES_XXXX; + + debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1); + +#if ENABLE_HUSH_LOOPS + /* Check syntax for "for" */ + for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) { + if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN) + continue; + /* current word is FOR or IN (BOLD in comments below) */ + if (cpipe->next == NULL) { + syntax("malformed for"); + debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level); + return 1; + } + /* "FOR v; do ..." and "for v IN a b; do..." are ok */ + if (cpipe->next->res_word == RES_DO) + continue; + /* next word is not "do". It must be "in" then ("FOR v in ...") */ + if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */ + || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */ + ) { + syntax("malformed for"); + debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level); + return 1; + } + } +#endif + + /* Past this point, all code paths should jump to ret: label + * in order to return, no direct "return" statements please. + * This helps to ensure that no memory is leaked. */ + +#if ENABLE_HUSH_JOB + /* Example of nested list: "while true; do { sleep 1 | exit 2; } done". + * We are saving state before entering outermost list ("while...done") + * so that ctrl-Z will correctly background _entire_ outermost list, + * not just a part of it (like "sleep 1 | exit 2") */ + if (++G.run_list_level == 1 && G.interactive_fd) { + if (sigsetjmp(G.toplevel_jb, 1)) { + /* ctrl-Z forked and we are parent; or ctrl-C. + * Sighandler has longjmped us here */ + signal(SIGINT, SIG_IGN); + signal(SIGTSTP, SIG_IGN); + /* Restore level (we can be coming from deep inside + * nested levels) */ + G.run_list_level = 1; +#if ENABLE_FEATURE_SH_STANDALONE + if (G.nofork_save.saved) { /* if save area is valid */ + debug_printf_jobs("exiting nofork early\n"); + restore_nofork_data(&G.nofork_save); + } +#endif + if (G.ctrl_z_flag) { + /* ctrl-Z has forked and stored pid of the child in pi->pid. + * Remember this child as background job */ + insert_bg_job(pi); + } else { + /* ctrl-C. We just stop doing whatever we were doing */ + bb_putchar('\n'); + } + USE_HUSH_LOOPS(loop_top = NULL;) + USE_HUSH_LOOPS(G.depth_of_loop = 0;) + rcode = 0; + goto ret; + } + /* ctrl-Z handler will store pid etc in pi */ + G.toplevel_list = pi; + G.ctrl_z_flag = 0; +#if ENABLE_FEATURE_SH_STANDALONE + G.nofork_save.saved = 0; /* in case we will run a nofork later */ +#endif + signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z); + signal(SIGINT, handler_ctrl_c); + } +#endif /* JOB */ + + /* Go through list of pipes, (maybe) executing them. */ + for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) { + IF_HAS_KEYWORDS(rword = pi->res_word;) + IF_HAS_NO_KEYWORDS(rword = RES_NONE;) + debug_printf_exec(": rword=%d cond_code=%d skip_more=%d\n", + rword, cond_code, skip_more_for_this_rword); +#if ENABLE_HUSH_LOOPS + if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) + && loop_top == NULL /* avoid bumping G.depth_of_loop twice */ + ) { + /* start of a loop: remember where loop starts */ + loop_top = pi; + G.depth_of_loop++; + } +#endif + if (rword == skip_more_for_this_rword && flag_skip) { + if (pi->followup == PIPE_SEQ) + flag_skip = 0; + /* it is "<false> && CMD" or "<true> || CMD" + * and we should not execute CMD */ + continue; + } + flag_skip = 1; + skip_more_for_this_rword = RES_XXXX; +#if ENABLE_HUSH_IF + if (cond_code) { + if (rword == RES_THEN) { + /* "if <false> THEN cmd": skip cmd */ + continue; + } + } else { + if (rword == RES_ELSE || rword == RES_ELIF) { + /* "if <true> then ... ELSE/ELIF cmd": + * skip cmd and all following ones */ + break; + } + } +#endif +#if ENABLE_HUSH_LOOPS + if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */ + if (!for_lcur) { + /* first loop through for */ + + static const char encoded_dollar_at[] ALIGN1 = { + SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0' + }; /* encoded representation of "$@" */ + static const char *const encoded_dollar_at_argv[] = { + encoded_dollar_at, NULL + }; /* argv list with one element: "$@" */ + char **vals; + + vals = (char**)encoded_dollar_at_argv; + if (pi->next->res_word == RES_IN) { + /* if no variable values after "in" we skip "for" */ + if (!pi->next->cmds[0].argv) + break; + vals = pi->next->cmds[0].argv; + } /* else: "for var; do..." -> assume "$@" list */ + /* create list of variable values */ + debug_print_strings("for_list made from", vals); + for_list = expand_strvec_to_strvec(vals); + for_lcur = for_list; + debug_print_strings("for_list", for_list); + for_varname = pi->cmds[0].argv[0]; + pi->cmds[0].argv[0] = NULL; + } + free(pi->cmds[0].argv[0]); + if (!*for_lcur) { + /* "for" loop is over, clean up */ + free(for_list); + for_list = NULL; + for_lcur = NULL; + pi->cmds[0].argv[0] = for_varname; + break; + } + /* insert next value from for_lcur */ +//TODO: does it need escaping? + pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++); + pi->cmds[0].assignment_cnt = 1; + } + if (rword == RES_IN) /* "for v IN list;..." - "in" has no cmds anyway */ + continue; + if (rword == RES_DONE) { + continue; /* "done" has no cmds too */ + } +#endif +#if ENABLE_HUSH_CASE + if (rword == RES_CASE) { + case_word = expand_strvec_to_string(pi->cmds->argv); + continue; + } + if (rword == RES_MATCH) { + char **argv; + + if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */ + break; + /* all prev words didn't match, does this one match? */ + argv = pi->cmds->argv; + while (*argv) { + char *pattern = expand_string_to_string(*argv); + /* TODO: which FNM_xxx flags to use? */ + cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0); + free(pattern); + if (cond_code == 0) { /* match! we will execute this branch */ + free(case_word); /* make future "word)" stop */ + case_word = NULL; + break; + } + argv++; + } + continue; + } + if (rword == RES_CASEI) { /* inside of a case branch */ + if (cond_code != 0) + continue; /* not matched yet, skip this pipe */ + } +#endif + if (pi->num_cmds == 0) + continue; + + /* After analyzing all keywords and conditions, we decided + * to execute this pipe. NB: has to do checkjobs(NULL) + * after run_pipe() to collect any background children, + * even if list execution is to be stopped. */ + debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds); + { + int r; +#if ENABLE_HUSH_LOOPS + G.flag_break_continue = 0; +#endif + rcode = r = run_pipe(pi); /* NB: rcode is a smallint */ + if (r != -1) { + /* we only ran a builtin: rcode is already known + * and we don't need to wait for anything. */ +#if ENABLE_HUSH_LOOPS + /* was it "break" or "continue"? */ + if (G.flag_break_continue) { + smallint fbc = G.flag_break_continue; + /* we might fall into outer *loop*, + * don't want to break it too */ + if (loop_top) { + G.depth_break_continue--; + if (G.depth_break_continue == 0) + G.flag_break_continue = 0; + /* else: e.g. "continue 2" should *break* once, *then* continue */ + } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */ + if (G.depth_break_continue != 0 || fbc == BC_BREAK) + goto check_jobs_and_break; + /* "continue": simulate end of loop */ + rword = RES_DONE; + continue; + } +#endif + } else if (pi->followup == PIPE_BG) { + /* what does bash do with attempts to background builtins? */ + /* even bash 3.2 doesn't do that well with nested bg: + * try "{ { sleep 10; echo DEEP; } & echo HERE; } &". + * I'm NOT treating inner &'s as jobs */ +#if ENABLE_HUSH_JOB + if (G.run_list_level == 1) + insert_bg_job(pi); +#endif + rcode = 0; /* EXIT_SUCCESS */ + } else { +#if ENABLE_HUSH_JOB + if (G.run_list_level == 1 && G.interactive_fd) { + /* waits for completion, then fg's main shell */ + rcode = checkjobs_and_fg_shell(pi); + debug_printf_exec(": checkjobs_and_fg_shell returned %d\n", rcode); + } else +#endif + { /* this one just waits for completion */ + rcode = checkjobs(pi); + debug_printf_exec(": checkjobs returned %d\n", rcode); + } + } + } + debug_printf_exec(": setting last_return_code=%d\n", rcode); + G.last_return_code = rcode; + + /* Analyze how result affects subsequent commands */ +#if ENABLE_HUSH_IF + if (rword == RES_IF || rword == RES_ELIF) + cond_code = rcode; +#endif +#if ENABLE_HUSH_LOOPS + if (rword == RES_WHILE) { + if (rcode) { + rcode = 0; /* "while false; do...done" - exitcode 0 */ + goto check_jobs_and_break; + } + } + if (rword == RES_UNTIL) { + if (!rcode) { + check_jobs_and_break: + checkjobs(NULL); + break; + } + } +#endif + if ((rcode == 0 && pi->followup == PIPE_OR) + || (rcode != 0 && pi->followup == PIPE_AND) + ) { + skip_more_for_this_rword = rword; + } + checkjobs(NULL); + } /* for (pi) */ + +#if ENABLE_HUSH_JOB + if (G.ctrl_z_flag) { + /* ctrl-Z forked somewhere in the past, we are the child, + * and now we completed running the list. Exit. */ +//TODO: _exit? + exit(rcode); + } + ret: + if (!--G.run_list_level && G.interactive_fd) { + signal(SIGTSTP, SIG_IGN); + signal(SIGINT, SIG_IGN); + } +#endif + debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode); +#if ENABLE_HUSH_LOOPS + if (loop_top) + G.depth_of_loop--; + free(for_list); +#endif +#if ENABLE_HUSH_CASE + free(case_word); +#endif + return rcode; +} + +/* return code is the exit status of the pipe */ +static int free_pipe(struct pipe *pi, int indent) +{ + char **p; + struct command *command; + struct redir_struct *r, *rnext; + int a, i, ret_code = 0; + + if (pi->stopped_cmds > 0) + return ret_code; + debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid()); + for (i = 0; i < pi->num_cmds; i++) { + command = &pi->cmds[i]; + debug_printf_clean("%s command %d:\n", indenter(indent), i); + if (command->argv) { + for (a = 0, p = command->argv; *p; a++, p++) { + debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p); + } + free_strings(command->argv); + command->argv = NULL; + } else if (command->group) { + debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type); + ret_code = free_pipe_list(command->group, indent+3); + debug_printf_clean("%s end group\n", indenter(indent)); + } else { + debug_printf_clean("%s (nil)\n", indenter(indent)); + } + for (r = command->redirects; r; r = rnext) { + debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip); + if (r->dup == -1) { + /* guard against the case >$FOO, where foo is unset or blank */ + if (r->rd_filename) { + debug_printf_clean(" %s\n", r->rd_filename); + free(r->rd_filename); + r->rd_filename = NULL; + } + } else { + debug_printf_clean("&%d\n", r->dup); + } + rnext = r->next; + free(r); + } + command->redirects = NULL; + } + free(pi->cmds); /* children are an array, they get freed all at once */ + pi->cmds = NULL; +#if ENABLE_HUSH_JOB + free(pi->cmdtext); + pi->cmdtext = NULL; +#endif + return ret_code; +} + +static int free_pipe_list(struct pipe *head, int indent) +{ + int rcode = 0; /* if list has no members */ + struct pipe *pi, *next; + + for (pi = head; pi; pi = next) { +#if HAS_KEYWORDS + debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word); +#endif + rcode = free_pipe(pi, indent); + debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup); + next = pi->next; + /*pi->next = NULL;*/ + free(pi); + } + return rcode; +} + +/* Select which version we will use */ +static int run_and_free_list(struct pipe *pi) +{ + int rcode = 0; + debug_printf_exec("run_and_free_list entered\n"); + if (!G.fake_mode) { + debug_printf_exec(": run_list with %d members\n", pi->num_cmds); + rcode = run_list(pi); + } + /* free_pipe_list has the side effect of clearing memory. + * In the long run that function can be merged with run_list, + * but doing that now would hobble the debugging effort. */ + free_pipe_list(pi, /* indent: */ 0); + debug_printf_exec("run_and_free_list return %d\n", rcode); + return rcode; +} + + +/* expand_strvec_to_strvec() takes a list of strings, expands + * all variable references within and returns a pointer to + * a list of expanded strings, possibly with larger number + * of strings. (Think VAR="a b"; echo $VAR). + * This new list is allocated as a single malloc block. + * NULL-terminated list of char* pointers is at the beginning of it, + * followed by strings themself. + * Caller can deallocate entire list by single free(list). */ + +/* Store given string, finalizing the word and starting new one whenever + * we encounter IFS char(s). This is used for expanding variable values. + * End-of-string does NOT finalize word: think about 'echo -$VAR-' */ +static int expand_on_ifs(o_string *output, int n, const char *str) +{ + while (1) { + int word_len = strcspn(str, G.ifs); + if (word_len) { + if (output->o_quote || !output->o_glob) + o_addQstr(output, str, word_len); + else /* protect backslashes against globbing up :) */ + o_addstr_duplicate_backslash(output, str, word_len); + str += word_len; + } + if (!*str) /* EOL - do not finalize word */ + break; + o_addchr(output, '\0'); + debug_print_list("expand_on_ifs", output, n); + n = o_save_ptr(output, n); + str += strspn(str, G.ifs); /* skip ifs chars */ + } + debug_print_list("expand_on_ifs[1]", output, n); + return n; +} + +/* Expand all variable references in given string, adding words to list[] + * at n, n+1,... positions. Return updated n (so that list[n] is next one + * to be filled). This routine is extremely tricky: has to deal with + * variables/parameters with whitespace, $* and $@, and constructs like + * 'echo -$*-'. If you play here, you must run testsuite afterwards! */ +static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask) +{ + /* or_mask is either 0 (normal case) or 0x80 + * (expansion of right-hand side of assignment == 1-element expand. + * It will also do no globbing, and thus we must not backslash-quote!) */ + + char first_ch, ored_ch; + int i; + const char *val; + char *p; + + ored_ch = 0; + + debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg); + debug_print_list("expand_vars_to_list", output, n); + n = o_save_ptr(output, n); + debug_print_list("expand_vars_to_list[0]", output, n); + + while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) { +#if ENABLE_HUSH_TICK + o_string subst_result = NULL_O_STRING; +#endif + o_addstr(output, arg, p - arg); + debug_print_list("expand_vars_to_list[1]", output, n); + arg = ++p; + p = strchr(p, SPECIAL_VAR_SYMBOL); + + first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */ + /* "$@" is special. Even if quoted, it can still + * expand to nothing (not even an empty string) */ + if ((first_ch & 0x7f) != '@') + ored_ch |= first_ch; + val = NULL; + switch (first_ch & 0x7f) { + /* Highest bit in first_ch indicates that var is double-quoted */ + case '$': /* pid */ + val = utoa(G.root_pid); + break; + case '!': /* bg pid */ + val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)""; + break; + case '?': /* exitcode */ + val = utoa(G.last_return_code); + break; + case '#': /* argc */ + val = utoa(G.global_argc ? G.global_argc-1 : 0); + break; + case '*': + case '@': + i = 1; + if (!G.global_argv[i]) + break; + ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */ + if (!(first_ch & 0x80)) { /* unquoted $* or $@ */ + smallint sv = output->o_quote; + /* unquoted var's contents should be globbed, so don't quote */ + output->o_quote = 0; + while (G.global_argv[i]) { + n = expand_on_ifs(output, n, G.global_argv[i]); + debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1); + if (G.global_argv[i++][0] && G.global_argv[i]) { + /* this argv[] is not empty and not last: + * put terminating NUL, start new word */ + o_addchr(output, '\0'); + debug_print_list("expand_vars_to_list[2]", output, n); + n = o_save_ptr(output, n); + debug_print_list("expand_vars_to_list[3]", output, n); + } + } + output->o_quote = sv; + } else + /* If or_mask is nonzero, we handle assignment 'a=....$@.....' + * and in this case should treat it like '$*' - see 'else...' below */ + if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */ + while (1) { + o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i])); + if (++i >= G.global_argc) + break; + o_addchr(output, '\0'); + debug_print_list("expand_vars_to_list[4]", output, n); + n = o_save_ptr(output, n); + } + } else { /* quoted $*: add as one word */ + while (1) { + o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i])); + if (!G.global_argv[++i]) + break; + if (G.ifs[0]) + o_addchr(output, G.ifs[0]); + } + } + break; + case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */ + /* "Empty variable", used to make "" etc to not disappear */ + arg++; + ored_ch = 0x80; + break; +#if ENABLE_HUSH_TICK + case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */ + struct in_str input; + *p = '\0'; + arg++; +//TODO: can we just stuff it into "output" directly? + debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch); + setup_string_in_str(&input, arg); + process_command_subs(&subst_result, &input, NULL); + debug_printf_subst("SUBST RES '%s'\n", subst_result.data); + val = subst_result.data; + goto store_val; + } +#endif + default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */ + *p = '\0'; + arg[0] = first_ch & 0x7f; + if (isdigit(arg[0])) { + i = xatoi_u(arg); + if (i < G.global_argc) + val = G.global_argv[i]; + /* else val remains NULL: $N with too big N */ + } else + val = lookup_param(arg); + arg[0] = first_ch; +#if ENABLE_HUSH_TICK + store_val: +#endif + *p = SPECIAL_VAR_SYMBOL; + if (!(first_ch & 0x80)) { /* unquoted $VAR */ + debug_printf_expand("unquoted '%s', output->o_quote:%d\n", val, output->o_quote); + if (val) { + /* unquoted var's contents should be globbed, so don't quote */ + smallint sv = output->o_quote; + output->o_quote = 0; + n = expand_on_ifs(output, n, val); + val = NULL; + output->o_quote = sv; + } + } else { /* quoted $VAR, val will be appended below */ + debug_printf_expand("quoted '%s', output->o_quote:%d\n", val, output->o_quote); + } + } + if (val) { + o_addQstr(output, val, strlen(val)); + } + +#if ENABLE_HUSH_TICK + o_free(&subst_result); +#endif + arg = ++p; + } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */ + + if (arg[0]) { + debug_print_list("expand_vars_to_list[a]", output, n); + /* this part is literal, and it was already pre-quoted + * if needed (much earlier), do not use o_addQstr here! */ + o_addstr(output, arg, strlen(arg) + 1); + debug_print_list("expand_vars_to_list[b]", output, n); + } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */ + && !(ored_ch & 0x80) /* and all vars were not quoted. */ + ) { + n--; + /* allow to reuse list[n] later without re-growth */ + output->has_empty_slot = 1; + } else { + o_addchr(output, '\0'); + } + return n; +} + +static char **expand_variables(char **argv, int or_mask) +{ + int n; + char **list; + char **v; + o_string output = NULL_O_STRING; + + if (or_mask & 0x100) { + output.o_quote = 1; /* protect against globbing for "$var" */ + /* (unquoted $var will temporarily switch it off) */ + output.o_glob = 1; + } + + n = 0; + v = argv; + while (*v) { + n = expand_vars_to_list(&output, n, *v, (char)or_mask); + v++; + } + debug_print_list("expand_variables", &output, n); + + /* output.data (malloced in one block) gets returned in "list" */ + list = o_finalize_list(&output, n); + debug_print_strings("expand_variables[1]", list); + return list; +} + +static char **expand_strvec_to_strvec(char **argv) +{ + return expand_variables(argv, 0x100); +} + +/* Used for expansion of right hand of assignments */ +/* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs + * "v=/bin/c*" */ +static char *expand_string_to_string(const char *str) +{ + char *argv[2], **list; + + argv[0] = (char*)str; + argv[1] = NULL; + list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */ + if (HUSH_DEBUG) + if (!list[0] || list[1]) + bb_error_msg_and_die("BUG in varexp2"); + /* actually, just move string 2*sizeof(char*) bytes back */ + strcpy((char*)list, list[0]); + debug_printf_expand("string_to_string='%s'\n", (char*)list); + return (char*)list; +} + +/* Used for "eval" builtin */ +static char* expand_strvec_to_string(char **argv) +{ + char **list; + + list = expand_variables(argv, 0x80); + /* Convert all NULs to spaces */ + if (list[0]) { + int n = 1; + while (list[n]) { + if (HUSH_DEBUG) + if (list[n-1] + strlen(list[n-1]) + 1 != list[n]) + bb_error_msg_and_die("BUG in varexp3"); + list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */ + n++; + } + } + strcpy((char*)list, list[0]); + debug_printf_expand("strvec_to_string='%s'\n", (char*)list); + return (char*)list; +} + + +/* Used to get/check local shell variables */ +static struct variable *get_local_var(const char *name) +{ + struct variable *cur; + int len; + + if (!name) + return NULL; + len = strlen(name); + for (cur = G.top_var; cur; cur = cur->next) { + if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=') + return cur; + } + return NULL; +} + +/* str holds "NAME=VAL" and is expected to be malloced. + * We take ownership of it. */ +static int set_local_var(char *str, int flg_export) +{ + struct variable *cur; + char *value; + int name_len; + + value = strchr(str, '='); + if (!value) { /* not expected to ever happen? */ + free(str); + return -1; + } + + name_len = value - str + 1; /* including '=' */ + cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */ + while (1) { + if (strncmp(cur->varstr, str, name_len) != 0) { + if (!cur->next) { + /* Bail out. Note that now cur points + * to last var in linked list */ + break; + } + cur = cur->next; + continue; + } + /* We found an existing var with this name */ + *value = '\0'; + if (cur->flg_read_only) { + bb_error_msg("%s: readonly variable", str); + free(str); + return -1; + } + debug_printf_env("%s: unsetenv '%s'\n", __func__, str); + unsetenv(str); /* just in case */ + *value = '='; + if (strcmp(cur->varstr, str) == 0) { + free_and_exp: + free(str); + goto exp; + } + if (cur->max_len >= strlen(str)) { + /* This one is from startup env, reuse space */ + strcpy(cur->varstr, str); + goto free_and_exp; + } + /* max_len == 0 signifies "malloced" var, which we can + * (and has to) free */ + if (!cur->max_len) + free(cur->varstr); + cur->max_len = 0; + goto set_str_and_exp; + } + + /* Not found - create next variable struct */ + cur->next = xzalloc(sizeof(*cur)); + cur = cur->next; + + set_str_and_exp: + cur->varstr = str; + exp: + if (flg_export) + cur->flg_export = 1; + if (cur->flg_export) { + debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr); + return putenv(cur->varstr); + } + return 0; +} + +static void unset_local_var(const char *name) +{ + struct variable *cur; + struct variable *prev = prev; /* for gcc */ + int name_len; + + if (!name) + return; + name_len = strlen(name); + cur = G.top_var; + while (cur) { + if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') { + if (cur->flg_read_only) { + bb_error_msg("%s: readonly variable", name); + return; + } + /* prev is ok to use here because 1st variable, HUSH_VERSION, + * is ro, and we cannot reach this code on the 1st pass */ + prev->next = cur->next; + debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr); + unsetenv(cur->varstr); + if (!cur->max_len) + free(cur->varstr); + free(cur); + return; + } + prev = cur; + cur = cur->next; + } +} + +/* The src parameter allows us to peek forward to a possible &n syntax + * for file descriptor duplication, e.g., "2>&1". + * Return code is 0 normally, 1 if a syntax error is detected in src. + * Resource errors (in xmalloc) cause the process to exit */ +static int setup_redirect(struct parse_context *ctx, int fd, redir_type style, + struct in_str *input) +{ + struct command *command = ctx->command; + struct redir_struct *redir = command->redirects; + struct redir_struct *last_redir = NULL; + + /* Create a new redir_struct and drop it onto the end of the linked list */ + while (redir) { + last_redir = redir; + redir = redir->next; + } + redir = xzalloc(sizeof(struct redir_struct)); + /* redir->next = NULL; */ + /* redir->rd_filename = NULL; */ + if (last_redir) { + last_redir->next = redir; + } else { + command->redirects = redir; + } + + redir->rd_type = style; + redir->fd = (fd == -1) ? redir_table[style].default_fd : fd; + + debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip); + + /* Check for a '2>&1' type redirect */ + redir->dup = redirect_dup_num(input); + if (redir->dup == -2) + return 1; /* syntax error */ + if (redir->dup != -1) { + /* Erik had a check here that the file descriptor in question + * is legit; I postpone that to "run time" + * A "-" representation of "close me" shows up as a -3 here */ + debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup); + } else { + /* We do _not_ try to open the file that src points to, + * since we need to return and let src be expanded first. + * Set ctx->pending_redirect, so we know what to do at the + * end of the next parsed word. */ + ctx->pending_redirect = redir; + } + return 0; +} + +static struct pipe *new_pipe(void) +{ + struct pipe *pi; + pi = xzalloc(sizeof(struct pipe)); + /*pi->followup = 0; - deliberately invalid value */ + /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */ + return pi; +} + +static void initialize_context(struct parse_context *ctx) +{ + memset(ctx, 0, sizeof(*ctx)); + ctx->pipe = ctx->list_head = new_pipe(); + /* Create the memory for command, roughly: + * ctx->pipe->cmds = new struct command; + * ctx->command = &ctx->pipe->cmds[0]; + */ + done_command(ctx); +} + +/* If a reserved word is found and processed, parse context is modified + * and 1 is returned. + * Handles if, then, elif, else, fi, for, while, until, do, done. + * case, function, and select are obnoxious, save those for later. + */ +#if HAS_KEYWORDS +struct reserved_combo { + char literal[6]; + unsigned char res; + unsigned char assignment_flag; + int flag; +}; +enum { + FLAG_END = (1 << RES_NONE ), +#if ENABLE_HUSH_IF + FLAG_IF = (1 << RES_IF ), + FLAG_THEN = (1 << RES_THEN ), + FLAG_ELIF = (1 << RES_ELIF ), + FLAG_ELSE = (1 << RES_ELSE ), + FLAG_FI = (1 << RES_FI ), +#endif +#if ENABLE_HUSH_LOOPS + FLAG_FOR = (1 << RES_FOR ), + FLAG_WHILE = (1 << RES_WHILE), + FLAG_UNTIL = (1 << RES_UNTIL), + FLAG_DO = (1 << RES_DO ), + FLAG_DONE = (1 << RES_DONE ), + FLAG_IN = (1 << RES_IN ), +#endif +#if ENABLE_HUSH_CASE + FLAG_MATCH = (1 << RES_MATCH), + FLAG_ESAC = (1 << RES_ESAC ), +#endif + FLAG_START = (1 << RES_XXXX ), +}; + +static const struct reserved_combo* match_reserved_word(o_string *word) +{ + /* Mostly a list of accepted follow-up reserved words. + * FLAG_END means we are done with the sequence, and are ready + * to turn the compound list into a command. + * FLAG_START means the word must start a new compound list. + */ + static const struct reserved_combo reserved_list[] = { +#if ENABLE_HUSH_IF + { "!", RES_NONE, NOT_ASSIGNMENT , 0 }, + { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START }, + { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI }, + { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN }, + { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI }, + { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END }, +#endif +#if ENABLE_HUSH_LOOPS + { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START }, + { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START }, + { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START }, + { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO }, + { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE }, + { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END }, +#endif +#if ENABLE_HUSH_CASE + { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START }, + { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END }, +#endif + }; + const struct reserved_combo *r; + + for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) { + if (strcmp(word->data, r->literal) == 0) + return r; + } + return NULL; +} +static int reserved_word(o_string *word, struct parse_context *ctx) +{ +#if ENABLE_HUSH_CASE + static const struct reserved_combo reserved_match = { + "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC + }; +#endif + const struct reserved_combo *r; + + r = match_reserved_word(word); + if (!r) + return 0; + + debug_printf("found reserved word %s, res %d\n", r->literal, r->res); +#if ENABLE_HUSH_CASE + if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE) + /* "case word IN ..." - IN part starts first match part */ + r = &reserved_match; + else +#endif + if (r->flag == 0) { /* '!' */ + if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */ + syntax(NULL); + IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;) + } + ctx->ctx_inverted = 1; + return 1; + } + if (r->flag & FLAG_START) { + struct parse_context *new; + debug_printf("push stack\n"); + new = xmalloc(sizeof(*new)); + *new = *ctx; /* physical copy */ + initialize_context(ctx); + ctx->stack = new; + } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) { + syntax(NULL); + ctx->ctx_res_w = RES_SNTX; + return 1; + } + ctx->ctx_res_w = r->res; + ctx->old_flag = r->flag; + if (ctx->old_flag & FLAG_END) { + struct parse_context *old; + debug_printf("pop stack\n"); + done_pipe(ctx, PIPE_SEQ); + old = ctx->stack; + old->command->group = ctx->list_head; + old->command->grp_type = GRP_NORMAL; + *ctx = *old; /* physical copy */ + free(old); + } + word->o_assignment = r->assignment_flag; + return 1; +} +#endif + +//TODO: many, many callers don't check error from done_word() + +/* Word is complete, look at it and update parsing context. + * Normal return is 0. Syntax errors return 1. */ +static int done_word(o_string *word, struct parse_context *ctx) +{ + struct command *command = ctx->command; + + debug_printf_parse("done_word entered: '%s' %p\n", word->data, command); + if (word->length == 0 && word->nonnull == 0) { + debug_printf_parse("done_word return 0: true null, ignored\n"); + return 0; + } + /* If this word wasn't an assignment, next ones definitely + * can't be assignments. Even if they look like ones. */ + if (word->o_assignment != DEFINITELY_ASSIGNMENT + && word->o_assignment != WORD_IS_KEYWORD + ) { + word->o_assignment = NOT_ASSIGNMENT; + } else { + if (word->o_assignment == DEFINITELY_ASSIGNMENT) + command->assignment_cnt++; + word->o_assignment = MAYBE_ASSIGNMENT; + } + + if (ctx->pending_redirect) { + /* We do not glob in e.g. >*.tmp case. bash seems to glob here + * only if run as "bash", not "sh" */ + ctx->pending_redirect->rd_filename = xstrdup(word->data); + word->o_assignment = NOT_ASSIGNMENT; + debug_printf("word stored in rd_filename: '%s'\n", word->data); + } else { + /* "{ echo foo; } echo bar" - bad */ + /* NB: bash allows e.g. "if true; then { echo foo; } fi". TODO? */ + if (command->group) { + syntax(NULL); + debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n"); + return 1; + } +#if HAS_KEYWORDS +#if ENABLE_HUSH_CASE + if (ctx->ctx_dsemicolon + && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */ + ) { + /* already done when ctx_dsemicolon was set to 1: */ + /* ctx->ctx_res_w = RES_MATCH; */ + ctx->ctx_dsemicolon = 0; + } else +#endif + + if (!command->argv /* if it's the first word... */ +#if ENABLE_HUSH_LOOPS + && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */ + && ctx->ctx_res_w != RES_IN +#endif + ) { + debug_printf_parse(": checking '%s' for reserved-ness\n", word->data); + if (reserved_word(word, ctx)) { + o_reset(word); + debug_printf_parse("done_word return %d\n", (ctx->ctx_res_w == RES_SNTX)); + return (ctx->ctx_res_w == RES_SNTX); + } + } +#endif + if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */ + /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */ + && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL) + /* (otherwise it's known to be not empty and is already safe) */ + ) { + /* exclude "$@" - it can expand to no word despite "" */ + char *p = word->data; + while (p[0] == SPECIAL_VAR_SYMBOL + && (p[1] & 0x7f) == '@' + && p[2] == SPECIAL_VAR_SYMBOL + ) { + p += 3; + } + if (p == word->data || p[0] != '\0') { + /* saw no "$@", or not only "$@" but some + * real text is there too */ + /* insert "empty variable" reference, this makes + * e.g. "", $empty"" etc to not disappear */ + o_addchr(word, SPECIAL_VAR_SYMBOL); + o_addchr(word, SPECIAL_VAR_SYMBOL); + } + } + command->argv = add_string_to_strings(command->argv, xstrdup(word->data)); + debug_print_strings("word appended to argv", command->argv); + } + + o_reset(word); + ctx->pending_redirect = NULL; + +#if ENABLE_HUSH_LOOPS + /* Force FOR to have just one word (variable name) */ + /* NB: basically, this makes hush see "for v in ..." syntax as if + * as it is "for v; in ...". FOR and IN become two pipe structs + * in parse tree. */ + if (ctx->ctx_res_w == RES_FOR) { +//TODO: check that command->argv[0] is a valid variable name! + done_pipe(ctx, PIPE_SEQ); + } +#endif +#if ENABLE_HUSH_CASE + /* Force CASE to have just one word */ + if (ctx->ctx_res_w == RES_CASE) { + done_pipe(ctx, PIPE_SEQ); + } +#endif + debug_printf_parse("done_word return 0\n"); + return 0; +} + +/* Command (member of a pipe) is complete. The only possible error here + * is out of memory, in which case xmalloc exits. */ +static int done_command(struct parse_context *ctx) +{ + /* The command is really already in the pipe structure, so + * advance the pipe counter and make a new, null command. */ + struct pipe *pi = ctx->pipe; + struct command *command = ctx->command; + + if (command) { + if (command->group == NULL + && command->argv == NULL + && command->redirects == NULL + ) { + debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds); + return pi->num_cmds; + } + pi->num_cmds++; + debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds); + } else { + debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds); + } + + /* Only real trickiness here is that the uncommitted + * command structure is not counted in pi->num_cmds. */ + pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1)); + command = &pi->cmds[pi->num_cmds]; + memset(command, 0, sizeof(*command)); + + ctx->command = command; + /* but ctx->pipe and ctx->list_head remain unchanged */ + + return pi->num_cmds; /* used only for 0/nonzero check */ +} + +static void done_pipe(struct parse_context *ctx, pipe_style type) +{ + int not_null; + + debug_printf_parse("done_pipe entered, followup %d\n", type); + /* Close previous command */ + not_null = done_command(ctx); + ctx->pipe->followup = type; + IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;) + IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;) + IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;) + + /* Without this check, even just <enter> on command line generates + * tree of three NOPs (!). Which is harmless but annoying. + * IOW: it is safe to do it unconditionally. + * RES_NONE case is for "for a in; do ..." (empty IN set) + * to work, possibly other cases too. */ + if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) { + struct pipe *new_p; + debug_printf_parse("done_pipe: adding new pipe: " + "not_null:%d ctx->ctx_res_w:%d\n", + not_null, ctx->ctx_res_w); + new_p = new_pipe(); + ctx->pipe->next = new_p; + ctx->pipe = new_p; + ctx->command = NULL; /* needed! */ + /* RES_THEN, RES_DO etc are "sticky" - + * they remain set for commands inside if/while. + * This is used to control execution. + * RES_FOR and RES_IN are NOT sticky (needed to support + * cases where variable or value happens to match a keyword): + */ +#if ENABLE_HUSH_LOOPS + if (ctx->ctx_res_w == RES_FOR + || ctx->ctx_res_w == RES_IN) + ctx->ctx_res_w = RES_NONE; +#endif +#if ENABLE_HUSH_CASE + if (ctx->ctx_res_w == RES_MATCH) + ctx->ctx_res_w = RES_CASEI; +#endif + /* Create the memory for command, roughly: + * ctx->pipe->cmds = new struct command; + * ctx->command = &ctx->pipe->cmds[0]; + */ + done_command(ctx); + } + debug_printf_parse("done_pipe return\n"); +} + +/* Peek ahead in the in_str to find out if we have a "&n" construct, + * as in "2>&1", that represents duplicating a file descriptor. + * Return either -2 (syntax error), -1 (no &), or the number found. + */ +static int redirect_dup_num(struct in_str *input) +{ + int ch, d = 0, ok = 0; + ch = i_peek(input); + if (ch != '&') return -1; + + i_getch(input); /* get the & */ + ch = i_peek(input); + if (ch == '-') { + i_getch(input); + return -3; /* "-" represents "close me" */ + } + while (isdigit(ch)) { + d = d*10 + (ch-'0'); + ok = 1; + i_getch(input); + ch = i_peek(input); + } + if (ok) return d; + + bb_error_msg("ambiguous redirect"); + return -2; +} + +/* If a redirect is immediately preceded by a number, that number is + * supposed to tell which file descriptor to redirect. This routine + * looks for such preceding numbers. In an ideal world this routine + * needs to handle all the following classes of redirects... + * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo + * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo + * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo + * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo + * A -1 output from this program means no valid number was found, so the + * caller should use the appropriate default for this redirection. + */ +static int redirect_opt_num(o_string *o) +{ + int num; + + if (o->length == 0) + return -1; + for (num = 0; num < o->length; num++) { + if (!isdigit(o->data[num])) { + return -1; + } + } + num = atoi(o->data); + o_reset(o); + return num; +} + +#if ENABLE_HUSH_TICK +static FILE *generate_stream_from_list(struct pipe *head) +{ + FILE *pf; + int pid, channel[2]; + + xpipe(channel); +/* *** NOMMU WARNING *** */ +/* By using vfork here, we suspend parent till child exits or execs. + * If child will not do it before it fills the pipe, it can block forever + * in write(STDOUT_FILENO), and parent (shell) will be also stuck. + * Try this script: + * yes "0123456789012345678901234567890" | dd bs=32 count=64k >TESTFILE + * huge=`cat TESTFILE` # will block here forever + * echo OK + */ + pid = BB_MMU ? fork() : vfork(); + if (pid < 0) + bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork"); + if (pid == 0) { /* child */ + if (ENABLE_HUSH_JOB) + die_sleep = 0; /* let nofork's xfuncs die */ + close(channel[0]); /* NB: close _first_, then move fd! */ + xmove_fd(channel[1], 1); + /* Prevent it from trying to handle ctrl-z etc */ +#if ENABLE_HUSH_JOB + G.run_list_level = 1; +#endif + /* Process substitution is not considered to be usual + * 'command execution'. + * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. */ + /* Not needed, we are relying on it being disabled + * everywhere outside actual command execution. */ + /*set_jobctrl_sighandler(SIG_IGN);*/ + set_misc_sighandler(SIG_DFL); + /* Freeing 'head' here would break NOMMU. */ + _exit(run_list(head)); + } + close(channel[1]); + pf = fdopen(channel[0], "r"); + return pf; + /* 'head' is freed by the caller */ +} + +/* Return code is exit status of the process that is run. */ +static int process_command_subs(o_string *dest, + struct in_str *input, + const char *subst_end) +{ + int retcode, ch, eol_cnt; + o_string result = NULL_O_STRING; + struct parse_context inner; + FILE *p; + struct in_str pipe_str; + + initialize_context(&inner); + + /* Recursion to generate command */ + retcode = parse_stream(&result, &inner, input, subst_end); + if (retcode != 0) + return retcode; /* syntax error or EOF */ + done_word(&result, &inner); + done_pipe(&inner, PIPE_SEQ); + o_free(&result); + + p = generate_stream_from_list(inner.list_head); + if (p == NULL) + return 1; + close_on_exec_on(fileno(p)); + setup_file_in_str(&pipe_str, p); + + /* Now send results of command back into original context */ + eol_cnt = 0; + while ((ch = i_getch(&pipe_str)) != EOF) { + if (ch == '\n') { + eol_cnt++; + continue; + } + while (eol_cnt) { + o_addchr(dest, '\n'); + eol_cnt--; + } + o_addQchr(dest, ch); + } + + debug_printf("done reading from pipe, pclose()ing\n"); + /* This is the step that wait()s for the child. Should be pretty + * safe, since we just read an EOF from its stdout. We could try + * to do better, by using wait(), and keeping track of background jobs + * at the same time. That would be a lot of work, and contrary + * to the KISS philosophy of this program. */ + retcode = fclose(p); + free_pipe_list(inner.list_head, /* indent: */ 0); + debug_printf("closed FILE from child, retcode=%d\n", retcode); + return retcode; +} +#endif + +static int parse_group(o_string *dest, struct parse_context *ctx, + struct in_str *input, int ch) +{ + /* dest contains characters seen prior to ( or {. + * Typically it's empty, but for functions defs, + * it contains function name (without '()'). */ + int rcode; + const char *endch = NULL; + struct parse_context sub; + struct command *command = ctx->command; + + debug_printf_parse("parse_group entered\n"); +#if ENABLE_HUSH_FUNCTIONS + if (ch == 'F') { /* function definition? */ + bb_error_msg("aha '%s' is a function, parsing it...", dest->data); + //command->fname = dest->data; + command->grp_type = GRP_FUNCTION; +//TODO: review every o_reset() location... do they handle all o_string fields correctly? + memset(dest, 0, sizeof(*dest)); + } +#endif + if (command->argv /* word [word](... */ + || dest->length /* word(... */ + || dest->nonnull /* ""(... */ + ) { + syntax(NULL); + debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n"); + return 1; + } + initialize_context(&sub); + endch = "}"; + if (ch == '(') { + endch = ")"; + command->grp_type = GRP_SUBSHELL; + } + rcode = parse_stream(dest, &sub, input, endch); + if (rcode == 0) { + done_word(dest, &sub); /* finish off the final word in the subcontext */ + done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */ + command->group = sub.list_head; + } + debug_printf_parse("parse_group return %d\n", rcode); + return rcode; + /* command remains "open", available for possible redirects */ +} + +/* Basically useful version until someone wants to get fancier, + * see the bash man page under "Parameter Expansion" */ +static const char *lookup_param(const char *src) +{ + struct variable *var = get_local_var(src); + if (var) + return strchr(var->varstr, '=') + 1; + return NULL; +} + +#if ENABLE_HUSH_TICK +/* Subroutines for copying $(...) and `...` things */ +static void add_till_backquote(o_string *dest, struct in_str *input); +/* '...' */ +static void add_till_single_quote(o_string *dest, struct in_str *input) +{ + while (1) { + int ch = i_getch(input); + if (ch == EOF) + break; + if (ch == '\'') + break; + o_addchr(dest, ch); + } +} +/* "...\"...`..`...." - do we need to handle "...$(..)..." too? */ +static void add_till_double_quote(o_string *dest, struct in_str *input) +{ + while (1) { + int ch = i_getch(input); + if (ch == '"') + break; + if (ch == '\\') { /* \x. Copy both chars. */ + o_addchr(dest, ch); + ch = i_getch(input); + } + if (ch == EOF) + break; + o_addchr(dest, ch); + if (ch == '`') { + add_till_backquote(dest, input); + o_addchr(dest, ch); + continue; + } + //if (ch == '$') ... + } +} +/* Process `cmd` - copy contents until "`" is seen. Complicated by + * \` quoting. + * "Within the backquoted style of command substitution, backslash + * shall retain its literal meaning, except when followed by: '$', '`', or '\'. + * The search for the matching backquote shall be satisfied by the first + * backquote found without a preceding backslash; during this search, + * if a non-escaped backquote is encountered within a shell comment, + * a here-document, an embedded command substitution of the $(command) + * form, or a quoted string, undefined results occur. A single-quoted + * or double-quoted string that begins, but does not end, within the + * "`...`" sequence produces undefined results." + * Example Output + * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST + */ +static void add_till_backquote(o_string *dest, struct in_str *input) +{ + while (1) { + int ch = i_getch(input); + if (ch == '`') + break; + if (ch == '\\') { /* \x. Copy both chars unless it is \` */ + int ch2 = i_getch(input); + if (ch2 != '`' && ch2 != '$' && ch2 != '\\') + o_addchr(dest, ch); + ch = ch2; + } + if (ch == EOF) + break; + o_addchr(dest, ch); + } +} +/* Process $(cmd) - copy contents until ")" is seen. Complicated by + * quoting and nested ()s. + * "With the $(command) style of command substitution, all characters + * following the open parenthesis to the matching closing parenthesis + * constitute the command. Any valid shell script can be used for command, + * except a script consisting solely of redirections which produces + * unspecified results." + * Example Output + * echo $(echo '(TEST)' BEST) (TEST) BEST + * echo $(echo 'TEST)' BEST) TEST) BEST + * echo $(echo \(\(TEST\) BEST) ((TEST) BEST + */ +static void add_till_closing_curly_brace(o_string *dest, struct in_str *input) +{ + int count = 0; + while (1) { + int ch = i_getch(input); + if (ch == EOF) + break; + if (ch == '(') + count++; + if (ch == ')') + if (--count < 0) + break; + o_addchr(dest, ch); + if (ch == '\'') { + add_till_single_quote(dest, input); + o_addchr(dest, ch); + continue; + } + if (ch == '"') { + add_till_double_quote(dest, input); + o_addchr(dest, ch); + continue; + } + if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */ + ch = i_getch(input); + if (ch == EOF) + break; + o_addchr(dest, ch); + continue; + } + } +} +#endif /* ENABLE_HUSH_TICK */ + +/* Return code: 0 for OK, 1 for syntax error */ +static int handle_dollar(o_string *dest, struct in_str *input) +{ + int ch = i_peek(input); /* first character after the $ */ + unsigned char quote_mask = dest->o_quote ? 0x80 : 0; + + debug_printf_parse("handle_dollar entered: ch='%c'\n", ch); + if (isalpha(ch)) { + i_getch(input); + make_var: + o_addchr(dest, SPECIAL_VAR_SYMBOL); + while (1) { + debug_printf_parse(": '%c'\n", ch); + o_addchr(dest, ch | quote_mask); + quote_mask = 0; + ch = i_peek(input); + if (!isalnum(ch) && ch != '_') + break; + i_getch(input); + } + o_addchr(dest, SPECIAL_VAR_SYMBOL); + } else if (isdigit(ch)) { + make_one_char_var: + i_getch(input); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + debug_printf_parse(": '%c'\n", ch); + o_addchr(dest, ch | quote_mask); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + } else switch (ch) { + case '$': /* pid */ + case '!': /* last bg pid */ + case '?': /* last exit code */ + case '#': /* number of args */ + case '*': /* args */ + case '@': /* args */ + goto make_one_char_var; + case '{': + o_addchr(dest, SPECIAL_VAR_SYMBOL); + i_getch(input); + /* XXX maybe someone will try to escape the '}' */ + while (1) { + ch = i_getch(input); + if (ch == '}') + break; + if (!isalnum(ch) && ch != '_') { + syntax("unterminated ${name}"); + debug_printf_parse("handle_dollar return 1: unterminated ${name}\n"); + return 1; + } + debug_printf_parse(": '%c'\n", ch); + o_addchr(dest, ch | quote_mask); + quote_mask = 0; + } + o_addchr(dest, SPECIAL_VAR_SYMBOL); + break; +#if ENABLE_HUSH_TICK + case '(': { + //int pos = dest->length; + i_getch(input); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + o_addchr(dest, quote_mask | '`'); + add_till_closing_curly_brace(dest, input); + //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + break; + } +#endif + case '_': + i_getch(input); + ch = i_peek(input); + if (isalnum(ch)) { /* it's $_name or $_123 */ + ch = '_'; + goto make_var; + } + /* else: it's $_ */ + case '-': + /* still unhandled, but should be eventually */ + bb_error_msg("unhandled syntax: $%c", ch); + return 1; + break; + default: + o_addQchr(dest, '$'); + } + debug_printf_parse("handle_dollar return 0\n"); + return 0; +} + +/* Scan input, call done_word() whenever full IFS delimited word was seen. + * Call done_pipe if '\n' was seen (and end_trigger != NULL). + * Return code is 0 if end_trigger char is met, + * -1 on EOF (but if end_trigger == NULL then return 0), + * 1 for syntax error */ +static int parse_stream(o_string *dest, struct parse_context *ctx, + struct in_str *input, const char *end_trigger) +{ + int ch, m; + int redir_fd; + redir_type redir_style; + int shadow_quote = dest->o_quote; + int next; + + /* Only double-quote state is handled in the state variable dest->o_quote. + * A single-quote triggers a bypass of the main loop until its mate is + * found. When recursing, quote state is passed in via dest->o_quote. */ + + debug_printf_parse("parse_stream entered, end_trigger='%s' dest->o_assignment:%d\n", end_trigger, dest->o_assignment); + + while (1) { + m = CHAR_IFS; + next = '\0'; + ch = i_getch(input); + if (ch != EOF) { + m = G.charmap[ch]; + if (ch != '\n') { + next = i_peek(input); + } + } + debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n", + ch, ch, m, dest->o_quote); + if (m == CHAR_ORDINARY + || (m != CHAR_SPECIAL && shadow_quote) + ) { + if (ch == EOF) { + syntax("unterminated \""); + debug_printf_parse("parse_stream return 1: unterminated \"\n"); + return 1; + } + o_addQchr(dest, ch); + if ((dest->o_assignment == MAYBE_ASSIGNMENT + || dest->o_assignment == WORD_IS_KEYWORD) + && ch == '=' + && is_assignment(dest->data) + ) { + dest->o_assignment = DEFINITELY_ASSIGNMENT; + } + continue; + } + if (m == CHAR_IFS) { + if (done_word(dest, ctx)) { + debug_printf_parse("parse_stream return 1: done_word!=0\n"); + return 1; + } + if (ch == EOF) + break; + /* If we aren't performing a substitution, treat + * a newline as a command separator. + * [why we don't handle it exactly like ';'? --vda] */ + if (end_trigger && ch == '\n') { +#if ENABLE_HUSH_CASE + /* "case ... in <newline> word) ..." - + * newlines are ignored (but ';' wouldn't be) */ + if (dest->length == 0 // && argv[0] == NULL + && ctx->ctx_res_w == RES_MATCH + ) { + continue; + } +#endif + done_pipe(ctx, PIPE_SEQ); + dest->o_assignment = MAYBE_ASSIGNMENT; + } + } + if (end_trigger) { + if (!shadow_quote && strchr(end_trigger, ch)) { + /* Special case: (...word) makes last word terminate, + * as if ';' is seen */ + if (ch == ')') { + done_word(dest, ctx); +//err chk? + done_pipe(ctx, PIPE_SEQ); + dest->o_assignment = MAYBE_ASSIGNMENT; + } + if (!HAS_KEYWORDS + IF_HAS_KEYWORDS(|| (ctx->ctx_res_w == RES_NONE && ctx->old_flag == 0)) + ) { + debug_printf_parse("parse_stream return 0: end_trigger char found\n"); + return 0; + } + } + } + if (m == CHAR_IFS) + continue; + + if (dest->o_assignment == MAYBE_ASSIGNMENT) { + /* ch is a special char and thus this word + * cannot be an assignment: */ + dest->o_assignment = NOT_ASSIGNMENT; + } + + switch (ch) { + case '#': + if (dest->length == 0 && !shadow_quote) { + while (1) { + ch = i_peek(input); + if (ch == EOF || ch == '\n') + break; + i_getch(input); + } + } else { + o_addQchr(dest, ch); + } + break; + case '\\': + if (next == EOF) { + syntax("\\<eof>"); + debug_printf_parse("parse_stream return 1: \\<eof>\n"); + return 1; + } + /* bash: + * "The backslash retains its special meaning [in "..."] + * only when followed by one of the following characters: + * $, `, ", \, or <newline>. A double quote may be quoted + * within double quotes by preceding it with a backslash. + * If enabled, history expansion will be performed unless + * an ! appearing in double quotes is escaped using + * a backslash. The backslash preceding the ! is not removed." + */ + if (shadow_quote) { //NOT SURE dest->o_quote) { + if (strchr("$`\"\\", next) != NULL) { + o_addqchr(dest, i_getch(input)); + } else { + o_addqchr(dest, '\\'); + } + } else { + o_addchr(dest, '\\'); + o_addchr(dest, i_getch(input)); + } + break; + case '$': + if (handle_dollar(dest, input) != 0) { + debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n"); + return 1; + } + break; + case '\'': + dest->nonnull = 1; + while (1) { + ch = i_getch(input); + if (ch == EOF) { + syntax("unterminated '"); + debug_printf_parse("parse_stream return 1: unterminated '\n"); + return 1; + } + if (ch == '\'') + break; + if (dest->o_assignment == NOT_ASSIGNMENT) + o_addqchr(dest, ch); + else + o_addchr(dest, ch); + } + break; + case '"': + dest->nonnull = 1; + shadow_quote ^= 1; /* invert */ + if (dest->o_assignment == NOT_ASSIGNMENT) + dest->o_quote ^= 1; + break; +#if ENABLE_HUSH_TICK + case '`': { + //int pos = dest->length; + o_addchr(dest, SPECIAL_VAR_SYMBOL); + o_addchr(dest, shadow_quote /*or dest->o_quote??*/ ? 0x80 | '`' : '`'); + add_till_backquote(dest, input); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos); + break; + } +#endif + case '>': + redir_fd = redirect_opt_num(dest); + done_word(dest, ctx); + redir_style = REDIRECT_OVERWRITE; + if (next == '>') { + redir_style = REDIRECT_APPEND; + i_getch(input); + } +#if 0 + else if (next == '(') { + syntax(">(process) not supported"); + debug_printf_parse("parse_stream return 1: >(process) not supported\n"); + return 1; + } +#endif + setup_redirect(ctx, redir_fd, redir_style, input); + break; + case '<': + redir_fd = redirect_opt_num(dest); + done_word(dest, ctx); + redir_style = REDIRECT_INPUT; + if (next == '<') { + redir_style = REDIRECT_HEREIS; + i_getch(input); + } else if (next == '>') { + redir_style = REDIRECT_IO; + i_getch(input); + } +#if 0 + else if (next == '(') { + syntax("<(process) not supported"); + debug_printf_parse("parse_stream return 1: <(process) not supported\n"); + return 1; + } +#endif + setup_redirect(ctx, redir_fd, redir_style, input); + break; + case ';': +#if ENABLE_HUSH_CASE + case_semi: +#endif + done_word(dest, ctx); + done_pipe(ctx, PIPE_SEQ); +#if ENABLE_HUSH_CASE + /* Eat multiple semicolons, detect + * whether it means something special */ + while (1) { + ch = i_peek(input); + if (ch != ';') + break; + i_getch(input); + if (ctx->ctx_res_w == RES_CASEI) { + ctx->ctx_dsemicolon = 1; + ctx->ctx_res_w = RES_MATCH; + break; + } + } +#endif + new_cmd: + /* We just finished a cmd. New one may start + * with an assignment */ + dest->o_assignment = MAYBE_ASSIGNMENT; + break; + case '&': + done_word(dest, ctx); + if (next == '&') { + i_getch(input); + done_pipe(ctx, PIPE_AND); + } else { + done_pipe(ctx, PIPE_BG); + } + goto new_cmd; + case '|': + done_word(dest, ctx); +#if ENABLE_HUSH_CASE + if (ctx->ctx_res_w == RES_MATCH) + break; /* we are in case's "word | word)" */ +#endif + if (next == '|') { /* || */ + i_getch(input); + done_pipe(ctx, PIPE_OR); + } else { + /* we could pick up a file descriptor choice here + * with redirect_opt_num(), but bash doesn't do it. + * "echo foo 2| cat" yields "foo 2". */ + done_command(ctx); + } + goto new_cmd; + case '(': +#if ENABLE_HUSH_CASE + /* "case... in [(]word)..." - skip '(' */ + if (ctx->ctx_res_w == RES_MATCH + && ctx->command->argv == NULL /* not (word|(... */ + && dest->length == 0 /* not word(... */ + && dest->nonnull == 0 /* not ""(... */ + ) { + continue; + } +#endif +#if ENABLE_HUSH_FUNCTIONS + if (dest->length != 0 /* not just () but word() */ + && dest->nonnull == 0 /* not a"b"c() */ + && ctx->command->argv == NULL /* it's the first word */ +//TODO: "func ( ) {...}" - note spaces - is valid format too in bash + && i_peek(input) == ')' + && !match_reserved_word(dest) + ) { + bb_error_msg("seems like a function definition"); + i_getch(input); + do { +//TODO: do it properly. + ch = i_getch(input); + } while (ch == ' ' || ch == '\n'); + if (ch != '{') { + syntax("was expecting {"); + debug_printf_parse("parse_stream return 1\n"); + return 1; + } + ch = 'F'; /* magic value */ + } +#endif + case '{': + if (parse_group(dest, ctx, input, ch) != 0) { + debug_printf_parse("parse_stream return 1: parse_group returned non-0\n"); + return 1; + } + goto new_cmd; + case ')': +#if ENABLE_HUSH_CASE + if (ctx->ctx_res_w == RES_MATCH) + goto case_semi; +#endif + case '}': + /* proper use of this character is caught by end_trigger: + * if we see {, we call parse_group(..., end_trigger='}') + * and it will match } earlier (not here). */ + syntax("unexpected } or )"); + debug_printf_parse("parse_stream return 1: unexpected '}'\n"); + return 1; + default: + if (HUSH_DEBUG) + bb_error_msg_and_die("BUG: unexpected %c\n", ch); + } + } /* while (1) */ + debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL)); + if (end_trigger) + return -1; + return 0; +} + +static void set_in_charmap(const char *set, int code) +{ + while (*set) + G.charmap[(unsigned char)*set++] = code; +} + +static void update_charmap(void) +{ + G.ifs = getenv("IFS"); + if (G.ifs == NULL) + G.ifs = " \t\n"; + /* Precompute a list of 'flow through' behavior so it can be treated + * quickly up front. Computation is necessary because of IFS. + * Special case handling of IFS == " \t\n" is not implemented. + * The charmap[] array only really needs two bits each, + * and on most machines that would be faster (reduced L1 cache use). + */ + memset(G.charmap, CHAR_ORDINARY, sizeof(G.charmap)); +#if ENABLE_HUSH_TICK + set_in_charmap("\\$\"`", CHAR_SPECIAL); +#else + set_in_charmap("\\$\"", CHAR_SPECIAL); +#endif + set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED); + set_in_charmap(G.ifs, CHAR_IFS); /* are ordinary if quoted */ +} + +/* Most recursion does not come through here, the exception is + * from builtin_source() and builtin_eval() */ +static int parse_and_run_stream(struct in_str *inp, int parse_flag) +{ + struct parse_context ctx; + o_string temp = NULL_O_STRING; + int rcode; + + do { + initialize_context(&ctx); + update_charmap(); +#if ENABLE_HUSH_INTERACTIVE + inp->promptmode = 0; /* PS1 */ +#endif + /* We will stop & execute after each ';' or '\n'. + * Example: "sleep 9999; echo TEST" + ctrl-C: + * TEST should be printed */ + temp.o_assignment = MAYBE_ASSIGNMENT; + rcode = parse_stream(&temp, &ctx, inp, ";\n"); +#if HAS_KEYWORDS + if (rcode != 1 && ctx.old_flag != 0) { + syntax(NULL); + } +#endif + if (rcode != 1 IF_HAS_KEYWORDS(&& ctx.old_flag == 0)) { + done_word(&temp, &ctx); + done_pipe(&ctx, PIPE_SEQ); + debug_print_tree(ctx.list_head, 0); + debug_printf_exec("parse_stream_outer: run_and_free_list\n"); + run_and_free_list(ctx.list_head); + } else { + /* We arrive here also if rcode == 1 (error in parse_stream) */ +#if HAS_KEYWORDS + if (ctx.old_flag != 0) { + free(ctx.stack); + o_reset(&temp); + } +#endif + /*temp.nonnull = 0; - o_free does it below */ + /*temp.o_quote = 0; - o_free does it below */ + free_pipe_list(ctx.list_head, /* indent: */ 0); + /* Discard all unprocessed line input, force prompt on */ + inp->p = NULL; +#if ENABLE_HUSH_INTERACTIVE + inp->promptme = 1; +#endif + } + o_free(&temp); + /* loop on syntax errors, return on EOF: */ + } while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP)); + return 0; +} + +static int parse_and_run_string(const char *s, int parse_flag) +{ + struct in_str input; + setup_string_in_str(&input, s); + return parse_and_run_stream(&input, parse_flag); +} + +static int parse_and_run_file(FILE *f) +{ + int rcode; + struct in_str input; + setup_file_in_str(&input, f); + rcode = parse_and_run_stream(&input, 0 /* parse_flag */); + return rcode; +} + +#if ENABLE_HUSH_JOB +/* Make sure we have a controlling tty. If we get started under a job + * aware app (like bash for example), make sure we are now in charge so + * we don't fight over who gets the foreground */ +static void setup_job_control(void) +{ + pid_t shell_pgrp; + + shell_pgrp = getpgrp(); + close_on_exec_on(G.interactive_fd); + + /* If we were ran as 'hush &', + * sleep until we are in the foreground. */ + while (tcgetpgrp(G.interactive_fd) != shell_pgrp) { + /* Send TTIN to ourself (should stop us) */ + kill(- shell_pgrp, SIGTTIN); + shell_pgrp = getpgrp(); + } + + /* Ignore job-control and misc signals. */ + set_jobctrl_sighandler(SIG_IGN); + set_misc_sighandler(SIG_IGN); +//huh? signal(SIGCHLD, SIG_IGN); + + /* We _must_ restore tty pgrp on fatal signals */ + set_fatal_sighandler(sigexit); + + /* Put ourselves in our own process group. */ + bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */ + /* Grab control of the terminal. */ + tcsetpgrp(G.interactive_fd, getpid()); +} +#endif + + +int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int hush_main(int argc, char **argv) +{ + static const struct variable const_shell_ver = { + .next = NULL, + .varstr = (char*)hush_version_str, + .max_len = 1, /* 0 can provoke free(name) */ + .flg_export = 1, + .flg_read_only = 1, + }; + + int opt; + FILE *input; + char **e; + struct variable *cur_var; + + INIT_G(); + + G.root_pid = getpid(); + + /* Deal with HUSH_VERSION */ + G.shell_ver = const_shell_ver; /* copying struct here */ + G.top_var = &G.shell_ver; + debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION"); + unsetenv("HUSH_VERSION"); /* in case it exists in initial env */ + /* Initialize our shell local variables with the values + * currently living in the environment */ + cur_var = G.top_var; + e = environ; + if (e) while (*e) { + char *value = strchr(*e, '='); + if (value) { /* paranoia */ + cur_var->next = xzalloc(sizeof(*cur_var)); + cur_var = cur_var->next; + cur_var->varstr = *e; + cur_var->max_len = strlen(*e); + cur_var->flg_export = 1; + } + e++; + } + debug_printf_env("putenv '%s'\n", hush_version_str); + putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */ + +#if ENABLE_FEATURE_EDITING + G.line_input_state = new_line_input_t(FOR_SHELL); +#endif + /* XXX what should these be while sourcing /etc/profile? */ + G.global_argc = argc; + G.global_argv = argv; + /* Initialize some more globals to non-zero values */ + set_cwd(); +#if ENABLE_HUSH_INTERACTIVE +#if ENABLE_FEATURE_EDITING + cmdedit_set_initial_prompt(); +#endif + G.PS2 = "> "; +#endif + + if (EXIT_SUCCESS) /* otherwise is already done */ + G.last_return_code = EXIT_SUCCESS; + + if (argv[0] && argv[0][0] == '-') { + debug_printf("sourcing /etc/profile\n"); + input = fopen_for_read("/etc/profile"); + if (input != NULL) { + close_on_exec_on(fileno(input)); + parse_and_run_file(input); + fclose(input); + } + } + input = stdin; + + while ((opt = getopt(argc, argv, "c:xif")) > 0) { + switch (opt) { + case 'c': + G.global_argv = argv + optind; + G.global_argc = argc - optind; + opt = parse_and_run_string(optarg, 0 /* parse_flag */); + goto final_return; + case 'i': + /* Well, we cannot just declare interactiveness, + * we have to have some stuff (ctty, etc) */ + /* G.interactive_fd++; */ + break; + case 'f': + G.fake_mode = 1; + break; + default: +#ifndef BB_VER + fprintf(stderr, "Usage: sh [FILE]...\n" + " or: sh -c command [args]...\n\n"); + exit(EXIT_FAILURE); +#else + bb_show_usage(); +#endif + } + } +#if ENABLE_HUSH_JOB + /* A shell is interactive if the '-i' flag was given, or if all of + * the following conditions are met: + * no -c command + * no arguments remaining or the -s flag given + * standard input is a terminal + * standard output is a terminal + * Refer to Posix.2, the description of the 'sh' utility. */ + if (argv[optind] == NULL && input == stdin + && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO) + ) { + G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO); + debug_printf("saved_tty_pgrp=%d\n", G.saved_tty_pgrp); + if (G.saved_tty_pgrp >= 0) { + /* try to dup to high fd#, >= 255 */ + G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255); + if (G.interactive_fd < 0) { + /* try to dup to any fd */ + G.interactive_fd = dup(STDIN_FILENO); + if (G.interactive_fd < 0) + /* give up */ + G.interactive_fd = 0; + } + // TODO: track & disallow any attempts of user + // to (inadvertently) close/redirect it + } + } + debug_printf("G.interactive_fd=%d\n", G.interactive_fd); + if (G.interactive_fd) { + fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC); + /* Looks like they want an interactive shell */ + setup_job_control(); + /* -1 is special - makes xfuncs longjmp, not exit + * (we reset die_sleep = 0 whereever we [v]fork) */ + die_sleep = -1; + if (setjmp(die_jmp)) { + /* xfunc has failed! die die die */ + hush_exit(xfunc_error_retval); + } +#if !ENABLE_FEATURE_SH_EXTRA_QUIET + printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner); + printf("Enter 'help' for a list of built-in commands.\n\n"); +#endif + } +#elif ENABLE_HUSH_INTERACTIVE +/* no job control compiled, only prompt/line editing */ + if (argv[optind] == NULL && input == stdin + && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO) + ) { + G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255); + if (G.interactive_fd < 0) { + /* try to dup to any fd */ + G.interactive_fd = dup(STDIN_FILENO); + if (G.interactive_fd < 0) + /* give up */ + G.interactive_fd = 0; + } + if (G.interactive_fd) { + fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC); + set_misc_sighandler(SIG_IGN); + } + } +#endif + + if (argv[optind] == NULL) { + opt = parse_and_run_file(stdin); + } else { + debug_printf("\nrunning script '%s'\n", argv[optind]); + G.global_argv = argv + optind; + G.global_argc = argc - optind; + input = xfopen_for_read(argv[optind]); + fcntl(fileno(input), F_SETFD, FD_CLOEXEC); + opt = parse_and_run_file(input); + } + + final_return: + +#if ENABLE_FEATURE_CLEAN_UP + fclose(input); + if (G.cwd != bb_msg_unknown) + free((char*)G.cwd); + cur_var = G.top_var->next; + while (cur_var) { + struct variable *tmp = cur_var; + if (!cur_var->max_len) + free(cur_var->varstr); + cur_var = cur_var->next; + free(tmp); + } +#endif + hush_exit(opt ? opt : G.last_return_code); +} + + +#if ENABLE_LASH +int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int lash_main(int argc, char **argv) +{ + //bb_error_msg("lash is deprecated, please use hush instead"); + return hush_main(argc, argv); +} +#endif + + +/* + * Built-ins + */ +static int builtin_true(char **argv UNUSED_PARAM) +{ + return 0; +} + +static int builtin_test(char **argv) +{ + int argc = 0; + while (*argv) { + argc++; + argv++; + } + return test_main(argc, argv - argc); +} + +static int builtin_echo(char **argv) +{ + int argc = 0; + while (*argv) { + argc++; + argv++; + } + return echo_main(argc, argv - argc); +} + +static int builtin_eval(char **argv) +{ + int rcode = EXIT_SUCCESS; + + if (argv[1]) { + char *str = expand_strvec_to_string(argv + 1); + parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP); + free(str); + rcode = G.last_return_code; + } + return rcode; +} + +static int builtin_cd(char **argv) +{ + const char *newdir; + if (argv[1] == NULL) { + // bash does nothing (exitcode 0) if HOME is ""; if it's unset, + // bash says "bash: cd: HOME not set" and does nothing (exitcode 1) + newdir = getenv("HOME") ? : "/"; + } else + newdir = argv[1]; + if (chdir(newdir)) { + printf("cd: %s: %s\n", newdir, strerror(errno)); + return EXIT_FAILURE; + } + set_cwd(); + return EXIT_SUCCESS; +} + +static int builtin_exec(char **argv) +{ + if (argv[1] == NULL) + return EXIT_SUCCESS; /* bash does this */ + { +#if !BB_MMU + nommu_save_t dummy; +#endif +// FIXME: if exec fails, bash does NOT exit! We do... + pseudo_exec_argv(&dummy, argv + 1, 0, NULL); + /* never returns */ + } +} + +static int builtin_exit(char **argv) +{ +// TODO: bash does it ONLY on top-level sh exit (+interacive only?) + //puts("exit"); /* bash does it */ +// TODO: warn if we have background jobs: "There are stopped jobs" +// On second consecutive 'exit', exit anyway. + if (argv[1] == NULL) + hush_exit(G.last_return_code); + /* mimic bash: exit 123abc == exit 255 + error msg */ + xfunc_error_retval = 255; + /* bash: exit -2 == exit 254, no error msg */ + hush_exit(xatoi(argv[1]) & 0xff); +} + +static int builtin_export(char **argv) +{ + const char *value; + char *name = argv[1]; + + if (name == NULL) { + // TODO: + // ash emits: export VAR='VAL' + // bash: declare -x VAR="VAL" + // (both also escape as needed (quotes, $, etc)) + char **e = environ; + if (e) + while (*e) + puts(*e++); + return EXIT_SUCCESS; + } + + value = strchr(name, '='); + if (!value) { + /* They are exporting something without a =VALUE */ + struct variable *var; + + var = get_local_var(name); + if (var) { + var->flg_export = 1; + debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr); + putenv(var->varstr); + } + /* bash does not return an error when trying to export + * an undefined variable. Do likewise. */ + return EXIT_SUCCESS; + } + + set_local_var(xstrdup(name), 1); + return EXIT_SUCCESS; +} + +#if ENABLE_HUSH_JOB +/* built-in 'fg' and 'bg' handler */ +static int builtin_fg_bg(char **argv) +{ + int i, jobnum; + struct pipe *pi; + + if (!G.interactive_fd) + return EXIT_FAILURE; + /* If they gave us no args, assume they want the last backgrounded task */ + if (!argv[1]) { + for (pi = G.job_list; pi; pi = pi->next) { + if (pi->jobid == G.last_jobid) { + goto found; + } + } + bb_error_msg("%s: no current job", argv[0]); + return EXIT_FAILURE; + } + if (sscanf(argv[1], "%%%d", &jobnum) != 1) { + bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]); + return EXIT_FAILURE; + } + for (pi = G.job_list; pi; pi = pi->next) { + if (pi->jobid == jobnum) { + goto found; + } + } + bb_error_msg("%s: %d: no such job", argv[0], jobnum); + return EXIT_FAILURE; + found: + // TODO: bash prints a string representation + // of job being foregrounded (like "sleep 1 | cat") + if (*argv[0] == 'f') { + /* Put the job into the foreground. */ + tcsetpgrp(G.interactive_fd, pi->pgrp); + } + + /* Restart the processes in the job */ + debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp); + for (i = 0; i < pi->num_cmds; i++) { + debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid); + pi->cmds[i].is_stopped = 0; + } + pi->stopped_cmds = 0; + + i = kill(- pi->pgrp, SIGCONT); + if (i < 0) { + if (errno == ESRCH) { + delete_finished_bg_job(pi); + return EXIT_SUCCESS; + } else { + bb_perror_msg("kill (SIGCONT)"); + } + } + + if (*argv[0] == 'f') { + remove_bg_job(pi); + return checkjobs_and_fg_shell(pi); + } + return EXIT_SUCCESS; +} +#endif + +#if ENABLE_HUSH_HELP +static int builtin_help(char **argv UNUSED_PARAM) +{ + const struct built_in_command *x; + + printf("\nBuilt-in commands:\n"); + printf("-------------------\n"); + for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) { + printf("%s\t%s\n", x->cmd, x->descr); + } + printf("\n\n"); + return EXIT_SUCCESS; +} +#endif + +#if ENABLE_HUSH_JOB +static int builtin_jobs(char **argv UNUSED_PARAM) +{ + struct pipe *job; + const char *status_string; + + for (job = G.job_list; job; job = job->next) { + if (job->alive_cmds == job->stopped_cmds) + status_string = "Stopped"; + else + status_string = "Running"; + + printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext); + } + return EXIT_SUCCESS; +} +#endif + +static int builtin_pwd(char **argv UNUSED_PARAM) +{ + puts(set_cwd()); + return EXIT_SUCCESS; +} + +static int builtin_read(char **argv) +{ + char *string; + const char *name = argv[1] ? argv[1] : "REPLY"; + + string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL); + return set_local_var(string, 0); +} + +/* built-in 'set [VAR=value]' handler */ +static int builtin_set(char **argv) +{ + char *temp = argv[1]; + struct variable *e; + + if (temp == NULL) + for (e = G.top_var; e; e = e->next) + puts(e->varstr); + else + set_local_var(xstrdup(temp), 0); + + return EXIT_SUCCESS; +} + +static int builtin_shift(char **argv) +{ + int n = 1; + if (argv[1]) { + n = atoi(argv[1]); + } + if (n >= 0 && n < G.global_argc) { + G.global_argv[n] = G.global_argv[0]; + G.global_argc -= n; + G.global_argv += n; + return EXIT_SUCCESS; + } + return EXIT_FAILURE; +} + +static int builtin_source(char **argv) +{ + FILE *input; + int status; + + if (argv[1] == NULL) + return EXIT_FAILURE; + + /* XXX search through $PATH is missing */ + input = fopen_for_read(argv[1]); + if (!input) { + bb_error_msg("can't open '%s'", argv[1]); + return EXIT_FAILURE; + } + close_on_exec_on(fileno(input)); + + /* Now run the file */ + /* XXX argv and argc are broken; need to save old G.global_argv + * (pointer only is OK!) on this stack frame, + * set G.global_argv=argv+1, recurse, and restore. */ + status = parse_and_run_file(input); + fclose(input); + return status; +} + +static int builtin_umask(char **argv) +{ + mode_t new_umask; + const char *arg = argv[1]; + char *end; + if (arg) { + new_umask = strtoul(arg, &end, 8); + if (*end != '\0' || end == arg) { + return EXIT_FAILURE; + } + } else { + new_umask = umask(0); + printf("%.3o\n", (unsigned) new_umask); + } + umask(new_umask); + return EXIT_SUCCESS; +} + +static int builtin_unset(char **argv) +{ + /* bash always returns true */ + unset_local_var(argv[1]); + return EXIT_SUCCESS; +} + +#if ENABLE_HUSH_LOOPS +static int builtin_break(char **argv) +{ + if (G.depth_of_loop == 0) { + bb_error_msg("%s: only meaningful in a loop", argv[0]); + return EXIT_SUCCESS; /* bash compat */ + } + G.flag_break_continue++; /* BC_BREAK = 1 */ + G.depth_break_continue = 1; + if (argv[1]) { + G.depth_break_continue = bb_strtou(argv[1], NULL, 10); + if (errno || !G.depth_break_continue || argv[2]) { + bb_error_msg("%s: bad arguments", argv[0]); + G.flag_break_continue = BC_BREAK; + G.depth_break_continue = UINT_MAX; + } + } + if (G.depth_of_loop < G.depth_break_continue) + G.depth_break_continue = G.depth_of_loop; + return EXIT_SUCCESS; +} + +static int builtin_continue(char **argv) +{ + G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */ + return builtin_break(argv); +} +#endif |