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Diffstat (limited to 'findutils/xargs.c')
| -rw-r--r-- | findutils/xargs.c | 535 |
1 files changed, 535 insertions, 0 deletions
diff --git a/findutils/xargs.c b/findutils/xargs.c new file mode 100644 index 0000000..f22d089 --- /dev/null +++ b/findutils/xargs.c @@ -0,0 +1,535 @@ +/* vi: set sw=4 ts=4: */ +/* + * Mini xargs implementation for busybox + * Options are supported: "-prtx -n max_arg -s max_chars -e[ouf_str]" + * + * (C) 2002,2003 by Vladimir Oleynik <dzo@simtreas.ru> + * + * Special thanks + * - Mark Whitley and Glenn McGrath for stimulus to rewrite :) + * - Mike Rendell <michael@cs.mun.ca> + * and David MacKenzie <djm@gnu.ai.mit.edu>. + * + * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. + * + * xargs is described in the Single Unix Specification v3 at + * http://www.opengroup.org/onlinepubs/007904975/utilities/xargs.html + * + */ + +#include "libbb.h" + +/* This is a NOEXEC applet. Be very careful! */ + + +/* COMPAT: SYSV version defaults size (and has a max value of) to 470. + We try to make it as large as possible. */ +#if !defined(ARG_MAX) && defined(_SC_ARG_MAX) +#define ARG_MAX sysconf (_SC_ARG_MAX) +#endif +#ifndef ARG_MAX +#define ARG_MAX 470 +#endif + + +#ifdef TEST +# ifndef ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION +# define ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION 1 +# endif +# ifndef ENABLE_FEATURE_XARGS_SUPPORT_QUOTES +# define ENABLE_FEATURE_XARGS_SUPPORT_QUOTES 1 +# endif +# ifndef ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT +# define ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT 1 +# endif +# ifndef ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM +# define ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM 1 +# endif +#endif + +/* + This function has special algorithm. + Don't use fork and include to main! +*/ +static int xargs_exec(char **args) +{ + int status; + + status = spawn_and_wait(args); + if (status < 0) { + bb_simple_perror_msg(args[0]); + return errno == ENOENT ? 127 : 126; + } + if (status == 255) { + bb_error_msg("%s: exited with status 255; aborting", args[0]); + return 124; + } +/* Huh? I think we won't see this, ever. We don't wait with WUNTRACED! + if (WIFSTOPPED(status)) { + bb_error_msg("%s: stopped by signal %d", + args[0], WSTOPSIG(status)); + return 125; + } +*/ + if (status >= 1000) { + bb_error_msg("%s: terminated by signal %d", + args[0], status - 1000); + return 125; + } + if (status) + return 123; + return 0; +} + + +typedef struct xlist_t { + struct xlist_t *link; + size_t length; + char xstr[1]; +} xlist_t; + +static smallint eof_stdin_detected; + +#define ISBLANK(c) ((c) == ' ' || (c) == '\t') +#define ISSPACE(c) (ISBLANK(c) || (c) == '\n' || (c) == '\r' \ + || (c) == '\f' || (c) == '\v') + +#if ENABLE_FEATURE_XARGS_SUPPORT_QUOTES +static xlist_t *process_stdin(xlist_t *list_arg, + const char *eof_str, size_t mc, char *buf) +{ +#define NORM 0 +#define QUOTE 1 +#define BACKSLASH 2 +#define SPACE 4 + + char *s = NULL; /* start word */ + char *p = NULL; /* pointer to end word */ + char q = '\0'; /* quote char */ + char state = NORM; + char eof_str_detected = 0; + size_t line_l = 0; /* size loaded args line */ + int c; /* current char */ + xlist_t *cur; + xlist_t *prev; + + prev = cur = list_arg; + while (1) { + if (!cur) break; + prev = cur; + line_l += cur->length; + cur = cur->link; + } + + while (!eof_stdin_detected) { + c = getchar(); + if (c == EOF) { + eof_stdin_detected = 1; + if (s) + goto unexpected_eof; + break; + } + if (eof_str_detected) + continue; + if (state == BACKSLASH) { + state = NORM; + goto set; + } else if (state == QUOTE) { + if (c != q) + goto set; + q = '\0'; + state = NORM; + } else { /* if (state == NORM) */ + if (ISSPACE(c)) { + if (s) { + unexpected_eof: + state = SPACE; + c = '\0'; + goto set; + } + } else { + if (s == NULL) + s = p = buf; + if (c == '\\') { + state = BACKSLASH; + } else if (c == '\'' || c == '"') { + q = c; + state = QUOTE; + } else { + set: + if ((size_t)(p - buf) >= mc) + bb_error_msg_and_die("argument line too long"); + *p++ = c; + } + } + } + if (state == SPACE) { /* word's delimiter or EOF detected */ + if (q) { + bb_error_msg_and_die("unmatched %s quote", + q == '\'' ? "single" : "double"); + } + /* word loaded */ + if (eof_str) { + eof_str_detected = (strcmp(s, eof_str) == 0); + } + if (!eof_str_detected) { + size_t length = (p - buf); + /* Dont xzalloc - it can be quite big */ + cur = xmalloc(offsetof(xlist_t, xstr) + length); + cur->link = NULL; + cur->length = length; + memcpy(cur->xstr, s, length); + if (prev == NULL) { + list_arg = cur; + } else { + prev->link = cur; + } + prev = cur; + line_l += length; + if (line_l > mc) { + /* stop memory usage :-) */ + break; + } + } + s = NULL; + state = NORM; + } + } + return list_arg; +} +#else +/* The variant does not support single quotes, double quotes or backslash */ +static xlist_t *process_stdin(xlist_t *list_arg, + const char *eof_str, size_t mc, char *buf) +{ + + int c; /* current char */ + char eof_str_detected = 0; + char *s = NULL; /* start word */ + char *p = NULL; /* pointer to end word */ + size_t line_l = 0; /* size loaded args line */ + xlist_t *cur; + xlist_t *prev; + + prev = cur = list_arg; + while (1) { + if (!cur) break; + prev = cur; + line_l += cur->length; + cur = cur->link; + } + + while (!eof_stdin_detected) { + c = getchar(); + if (c == EOF) { + eof_stdin_detected = 1; + } + if (eof_str_detected) + continue; + if (c == EOF || ISSPACE(c)) { + if (s == NULL) + continue; + c = EOF; + } + if (s == NULL) + s = p = buf; + if ((size_t)(p - buf) >= mc) + bb_error_msg_and_die("argument line too long"); + *p++ = (c == EOF ? '\0' : c); + if (c == EOF) { /* word's delimiter or EOF detected */ + /* word loaded */ + if (eof_str) { + eof_str_detected = (strcmp(s, eof_str) == 0); + } + if (!eof_str_detected) { + size_t length = (p - buf); + /* Dont xzalloc - it can be quite big */ + cur = xmalloc(offsetof(xlist_t, xstr) + length); + cur->link = NULL; + cur->length = length; + memcpy(cur->xstr, s, length); + if (prev == NULL) { + list_arg = cur; + } else { + prev->link = cur; + } + prev = cur; + line_l += length; + if (line_l > mc) { + /* stop memory usage :-) */ + break; + } + s = NULL; + } + } + } + return list_arg; +} +#endif /* FEATURE_XARGS_SUPPORT_QUOTES */ + + +#if ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION +/* Prompt the user for a response, and + if the user responds affirmatively, return true; + otherwise, return false. Uses "/dev/tty", not stdin. */ +static int xargs_ask_confirmation(void) +{ + FILE *tty_stream; + int c, savec; + + tty_stream = xfopen_for_read(CURRENT_TTY); + fputs(" ?...", stderr); + fflush(stderr); + c = savec = getc(tty_stream); + while (c != EOF && c != '\n') + c = getc(tty_stream); + fclose(tty_stream); + return (savec == 'y' || savec == 'Y'); +} +#else +# define xargs_ask_confirmation() 1 +#endif /* FEATURE_XARGS_SUPPORT_CONFIRMATION */ + +#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM +static xlist_t *process0_stdin(xlist_t *list_arg, + const char *eof_str UNUSED_PARAM, size_t mc, char *buf) +{ + int c; /* current char */ + char *s = NULL; /* start word */ + char *p = NULL; /* pointer to end word */ + size_t line_l = 0; /* size loaded args line */ + xlist_t *cur; + xlist_t *prev; + + prev = cur = list_arg; + while (1) { + if (!cur) break; + prev = cur; + line_l += cur->length; + cur = cur->link; + } + + while (!eof_stdin_detected) { + c = getchar(); + if (c == EOF) { + eof_stdin_detected = 1; + if (s == NULL) + break; + c = '\0'; + } + if (s == NULL) + s = p = buf; + if ((size_t)(p - buf) >= mc) + bb_error_msg_and_die("argument line too long"); + *p++ = c; + if (c == '\0') { /* word's delimiter or EOF detected */ + /* word loaded */ + size_t length = (p - buf); + /* Dont xzalloc - it can be quite big */ + cur = xmalloc(offsetof(xlist_t, xstr) + length); + cur->link = NULL; + cur->length = length; + memcpy(cur->xstr, s, length); + if (prev == NULL) { + list_arg = cur; + } else { + prev->link = cur; + } + prev = cur; + line_l += length; + if (line_l > mc) { + /* stop memory usage :-) */ + break; + } + s = NULL; + } + } + return list_arg; +} +#endif /* FEATURE_XARGS_SUPPORT_ZERO_TERM */ + +/* Correct regardless of combination of CONFIG_xxx */ +enum { + OPTBIT_VERBOSE = 0, + OPTBIT_NO_EMPTY, + OPTBIT_UPTO_NUMBER, + OPTBIT_UPTO_SIZE, + OPTBIT_EOF_STRING, + OPTBIT_EOF_STRING1, + USE_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,) + USE_FEATURE_XARGS_SUPPORT_TERMOPT( OPTBIT_TERMINATE ,) + USE_FEATURE_XARGS_SUPPORT_ZERO_TERM( OPTBIT_ZEROTERM ,) + + OPT_VERBOSE = 1 << OPTBIT_VERBOSE , + OPT_NO_EMPTY = 1 << OPTBIT_NO_EMPTY , + OPT_UPTO_NUMBER = 1 << OPTBIT_UPTO_NUMBER, + OPT_UPTO_SIZE = 1 << OPTBIT_UPTO_SIZE , + OPT_EOF_STRING = 1 << OPTBIT_EOF_STRING , /* GNU: -e[<param>] */ + OPT_EOF_STRING1 = 1 << OPTBIT_EOF_STRING1, /* SUS: -E<param> */ + OPT_INTERACTIVE = USE_FEATURE_XARGS_SUPPORT_CONFIRMATION((1 << OPTBIT_INTERACTIVE)) + 0, + OPT_TERMINATE = USE_FEATURE_XARGS_SUPPORT_TERMOPT( (1 << OPTBIT_TERMINATE )) + 0, + OPT_ZEROTERM = USE_FEATURE_XARGS_SUPPORT_ZERO_TERM( (1 << OPTBIT_ZEROTERM )) + 0, +}; +#define OPTION_STR "+trn:s:e::E:" \ + USE_FEATURE_XARGS_SUPPORT_CONFIRMATION("p") \ + USE_FEATURE_XARGS_SUPPORT_TERMOPT( "x") \ + USE_FEATURE_XARGS_SUPPORT_ZERO_TERM( "0") + +int xargs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int xargs_main(int argc, char **argv) +{ + char **args; + int i, n; + xlist_t *list = NULL; + xlist_t *cur; + int child_error = 0; + char *max_args, *max_chars; + int n_max_arg; + size_t n_chars = 0; + long orig_arg_max; + const char *eof_str = NULL; + unsigned opt; + size_t n_max_chars; +#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM + xlist_t* (*read_args)(xlist_t*, const char*, size_t, char*) = process_stdin; +#else +#define read_args process_stdin +#endif + + opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &eof_str, &eof_str); + + /* -E ""? You may wonder why not just omit -E? + * This is used for portability: + * old xargs was using "_" as default for -E / -e */ + if ((opt & OPT_EOF_STRING1) && eof_str[0] == '\0') + eof_str = NULL; + + if (opt & OPT_ZEROTERM) + USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin); + + argv += optind; + argc -= optind; + if (!argc) { + /* default behavior is to echo all the filenames */ + *argv = (char*)"echo"; + argc++; + } + + orig_arg_max = ARG_MAX; + if (orig_arg_max == -1) + orig_arg_max = LONG_MAX; + orig_arg_max -= 2048; /* POSIX.2 requires subtracting 2048 */ + + if (opt & OPT_UPTO_SIZE) { + n_max_chars = xatoul_range(max_chars, 1, orig_arg_max); + for (i = 0; i < argc; i++) { + n_chars += strlen(*argv) + 1; + } + if (n_max_chars < n_chars) { + bb_error_msg_and_die("cannot fit single argument within argument list size limit"); + } + n_max_chars -= n_chars; + } else { + /* Sanity check for systems with huge ARG_MAX defines (e.g., Suns which + have it at 1 meg). Things will work fine with a large ARG_MAX but it + will probably hurt the system more than it needs to; an array of this + size is allocated. */ + if (orig_arg_max > 20 * 1024) + orig_arg_max = 20 * 1024; + n_max_chars = orig_arg_max; + } + max_chars = xmalloc(n_max_chars); + + if (opt & OPT_UPTO_NUMBER) { + n_max_arg = xatoul_range(max_args, 1, INT_MAX); + } else { + n_max_arg = n_max_chars; + } + + while ((list = read_args(list, eof_str, n_max_chars, max_chars)) != NULL || + !(opt & OPT_NO_EMPTY)) + { + opt |= OPT_NO_EMPTY; + n = 0; + n_chars = 0; +#if ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT + for (cur = list; cur;) { + n_chars += cur->length; + n++; + cur = cur->link; + if (n_chars > n_max_chars || (n == n_max_arg && cur)) { + if (opt & OPT_TERMINATE) + bb_error_msg_and_die("argument list too long"); + break; + } + } +#else + for (cur = list; cur; cur = cur->link) { + n_chars += cur->length; + n++; + if (n_chars > n_max_chars || n == n_max_arg) { + break; + } + } +#endif /* FEATURE_XARGS_SUPPORT_TERMOPT */ + + /* allocate pointers for execvp: + argc*arg, n*arg from stdin, NULL */ + args = xzalloc((n + argc + 1) * sizeof(char *)); + + /* store the command to be executed + (taken from the command line) */ + for (i = 0; i < argc; i++) + args[i] = argv[i]; + /* (taken from stdin) */ + for (cur = list; n; cur = cur->link) { + args[i++] = cur->xstr; + n--; + } + + if (opt & (OPT_INTERACTIVE | OPT_VERBOSE)) { + for (i = 0; args[i]; i++) { + if (i) + fputc(' ', stderr); + fputs(args[i], stderr); + } + if (!(opt & OPT_INTERACTIVE)) + fputc('\n', stderr); + } + if (!(opt & OPT_INTERACTIVE) || xargs_ask_confirmation()) { + child_error = xargs_exec(args); + } + + /* clean up */ + for (i = argc; args[i]; i++) { + cur = list; + list = list->link; + free(cur); + } + free(args); + if (child_error > 0 && child_error != 123) { + break; + } + } /* while */ + if (ENABLE_FEATURE_CLEAN_UP) + free(max_chars); + return child_error; +} + + +#ifdef TEST + +const char *applet_name = "debug stuff usage"; + +void bb_show_usage(void) +{ + fprintf(stderr, "Usage: %s [-p] [-r] [-t] -[x] [-n max_arg] [-s max_chars]\n", + applet_name); + exit(EXIT_FAILURE); +} + +int main(int argc, char **argv) +{ + return xargs_main(argc, argv); +} +#endif /* TEST */ |