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Diffstat (limited to 'editors/sed.c')
-rw-r--r-- | editors/sed.c | 1349 |
1 files changed, 1349 insertions, 0 deletions
diff --git a/editors/sed.c b/editors/sed.c new file mode 100644 index 0000000..eb31f7d --- /dev/null +++ b/editors/sed.c @@ -0,0 +1,1349 @@ +/* vi: set sw=4 ts=4: */ +/* + * sed.c - very minimalist version of sed + * + * Copyright (C) 1999,2000,2001 by Lineo, inc. and Mark Whitley + * Copyright (C) 1999,2000,2001 by Mark Whitley <markw@codepoet.org> + * Copyright (C) 2002 Matt Kraai + * Copyright (C) 2003 by Glenn McGrath + * Copyright (C) 2003,2004 by Rob Landley <rob@landley.net> + * + * MAINTAINER: Rob Landley <rob@landley.net> + * + * Licensed under GPL version 2, see file LICENSE in this tarball for details. + */ + +/* Code overview. + + Files are laid out to avoid unnecessary function declarations. So for + example, every function add_cmd calls occurs before add_cmd in this file. + + add_cmd() is called on each line of sed command text (from a file or from + the command line). It calls get_address() and parse_cmd_args(). The + resulting sed_cmd_t structures are appended to a linked list + (G.sed_cmd_head/G.sed_cmd_tail). + + add_input_file() adds a FILE* to the list of input files. We need to + know all input sources ahead of time to find the last line for the $ match. + + process_files() does actual sedding, reading data lines from each input FILE * + (which could be stdin) and applying the sed command list (sed_cmd_head) to + each of the resulting lines. + + sed_main() is where external code calls into this, with a command line. +*/ + + +/* + Supported features and commands in this version of sed: + + - comments ('#') + - address matching: num|/matchstr/[,num|/matchstr/|$]command + - commands: (p)rint, (d)elete, (s)ubstitue (with g & I flags) + - edit commands: (a)ppend, (i)nsert, (c)hange + - file commands: (r)ead + - backreferences in substitution expressions (\0, \1, \2...\9) + - grouped commands: {cmd1;cmd2} + - transliteration (y/source-chars/dest-chars/) + - pattern space hold space storing / swapping (g, h, x) + - labels / branching (: label, b, t, T) + + (Note: Specifying an address (range) to match is *optional*; commands + default to the whole pattern space if no specific address match was + requested.) + + Todo: + - Create a wrapper around regex to make libc's regex conform with sed + + Reference http://www.opengroup.org/onlinepubs/007904975/utilities/sed.html +*/ + +#include "libbb.h" +#include "xregex.h" + +/* Each sed command turns into one of these structures. */ +typedef struct sed_cmd_s { + /* Ordered by alignment requirements: currently 36 bytes on x86 */ + struct sed_cmd_s *next; /* Next command (linked list, NULL terminated) */ + + /* address storage */ + regex_t *beg_match; /* sed -e '/match/cmd' */ + regex_t *end_match; /* sed -e '/match/,/end_match/cmd' */ + regex_t *sub_match; /* For 's/sub_match/string/' */ + int beg_line; /* 'sed 1p' 0 == apply commands to all lines */ + int end_line; /* 'sed 1,3p' 0 == one line only. -1 = last line ($) */ + + FILE *sw_file; /* File (sw) command writes to, -1 for none. */ + char *string; /* Data string for (saicytb) commands. */ + + unsigned which_match; /* (s) Which match to replace (0 for all) */ + + /* Bitfields (gcc won't group them if we don't) */ + unsigned invert:1; /* the '!' after the address */ + unsigned in_match:1; /* Next line also included in match? */ + unsigned sub_p:1; /* (s) print option */ + + char sw_last_char; /* Last line written by (sw) had no '\n' */ + + /* GENERAL FIELDS */ + char cmd; /* The command char: abcdDgGhHilnNpPqrstwxy:={} */ +} sed_cmd_t; + +static const char semicolon_whitespace[] ALIGN1 = "; \n\r\t\v"; + +struct globals { + /* options */ + int be_quiet, regex_type; + FILE *nonstdout; + char *outname, *hold_space; + + /* List of input files */ + int input_file_count, current_input_file; + FILE **input_file_list; + + regmatch_t regmatch[10]; + regex_t *previous_regex_ptr; + + /* linked list of sed commands */ + sed_cmd_t sed_cmd_head, *sed_cmd_tail; + + /* Linked list of append lines */ + llist_t *append_head; + + char *add_cmd_line; + + struct pipeline { + char *buf; /* Space to hold string */ + int idx; /* Space used */ + int len; /* Space allocated */ + } pipeline; +}; +#define G (*(struct globals*)&bb_common_bufsiz1) +void BUG_sed_globals_too_big(void); +#define INIT_G() do { \ + if (sizeof(struct globals) > COMMON_BUFSIZE) \ + BUG_sed_globals_too_big(); \ + G.sed_cmd_tail = &G.sed_cmd_head; \ +} while (0) + + +#if ENABLE_FEATURE_CLEAN_UP +static void sed_free_and_close_stuff(void) +{ + sed_cmd_t *sed_cmd = G.sed_cmd_head.next; + + llist_free(G.append_head, free); + + while (sed_cmd) { + sed_cmd_t *sed_cmd_next = sed_cmd->next; + + if (sed_cmd->sw_file) + xprint_and_close_file(sed_cmd->sw_file); + + if (sed_cmd->beg_match) { + regfree(sed_cmd->beg_match); + free(sed_cmd->beg_match); + } + if (sed_cmd->end_match) { + regfree(sed_cmd->end_match); + free(sed_cmd->end_match); + } + if (sed_cmd->sub_match) { + regfree(sed_cmd->sub_match); + free(sed_cmd->sub_match); + } + free(sed_cmd->string); + free(sed_cmd); + sed_cmd = sed_cmd_next; + } + + free(G.hold_space); + + while (G.current_input_file < G.input_file_count) + fclose(G.input_file_list[G.current_input_file++]); +} +#else +void sed_free_and_close_stuff(void); +#endif + +/* If something bad happens during -i operation, delete temp file */ + +static void cleanup_outname(void) +{ + if (G.outname) unlink(G.outname); +} + +/* strcpy, replacing "\from" with 'to'. If to is NUL, replacing "\any" with 'any' */ + +static void parse_escapes(char *dest, const char *string, int len, char from, char to) +{ + int i = 0; + + while (i < len) { + if (string[i] == '\\') { + if (!to || string[i+1] == from) { + *dest++ = to ? to : string[i+1]; + i += 2; + continue; + } + *dest++ = string[i++]; + } + /* TODO: is it safe wrt a string with trailing '\\' ? */ + *dest++ = string[i++]; + } + *dest = '\0'; +} + +static char *copy_parsing_escapes(const char *string, int len) +{ + char *dest = xmalloc(len + 1); + + parse_escapes(dest, string, len, 'n', '\n'); + /* GNU sed also recognizes \t */ + parse_escapes(dest, dest, strlen(dest), 't', '\t'); + return dest; +} + + +/* + * index_of_next_unescaped_regexp_delim - walks left to right through a string + * beginning at a specified index and returns the index of the next regular + * expression delimiter (typically a forward slash ('/')) not preceded by + * a backslash ('\'). A negative delimiter disables square bracket checking. + */ +static int index_of_next_unescaped_regexp_delim(int delimiter, const char *str) +{ + int bracket = -1; + int escaped = 0; + int idx = 0; + char ch; + + if (delimiter < 0) { + bracket--; + delimiter = -delimiter; + } + + for (; (ch = str[idx]); idx++) { + if (bracket >= 0) { + if (ch == ']' && !(bracket == idx - 1 || (bracket == idx - 2 + && str[idx - 1] == '^'))) + bracket = -1; + } else if (escaped) + escaped = 0; + else if (ch == '\\') + escaped = 1; + else if (bracket == -1 && ch == '[') + bracket = idx; + else if (ch == delimiter) + return idx; + } + + /* if we make it to here, we've hit the end of the string */ + bb_error_msg_and_die("unmatched '%c'", delimiter); +} + +/* + * Returns the index of the third delimiter + */ +static int parse_regex_delim(const char *cmdstr, char **match, char **replace) +{ + const char *cmdstr_ptr = cmdstr; + char delimiter; + int idx = 0; + + /* verify that the 's' or 'y' is followed by something. That something + * (typically a 'slash') is now our regexp delimiter... */ + if (*cmdstr == '\0') + bb_error_msg_and_die("bad format in substitution expression"); + delimiter = *cmdstr_ptr++; + + /* save the match string */ + idx = index_of_next_unescaped_regexp_delim(delimiter, cmdstr_ptr); + *match = copy_parsing_escapes(cmdstr_ptr, idx); + + /* save the replacement string */ + cmdstr_ptr += idx + 1; + idx = index_of_next_unescaped_regexp_delim(-delimiter, cmdstr_ptr); + *replace = copy_parsing_escapes(cmdstr_ptr, idx); + + return ((cmdstr_ptr - cmdstr) + idx); +} + +/* + * returns the index in the string just past where the address ends. + */ +static int get_address(const char *my_str, int *linenum, regex_t ** regex) +{ + const char *pos = my_str; + + if (isdigit(*my_str)) { + *linenum = strtol(my_str, (char**)&pos, 10); + /* endstr shouldnt ever equal NULL */ + } else if (*my_str == '$') { + *linenum = -1; + pos++; + } else if (*my_str == '/' || *my_str == '\\') { + int next; + char delimiter; + char *temp; + + delimiter = '/'; + if (*my_str == '\\') delimiter = *++pos; + next = index_of_next_unescaped_regexp_delim(delimiter, ++pos); + temp = copy_parsing_escapes(pos, next); + *regex = xmalloc(sizeof(regex_t)); + xregcomp(*regex, temp, G.regex_type|REG_NEWLINE); + free(temp); + /* Move position to next character after last delimiter */ + pos += (next+1); + } + return pos - my_str; +} + +/* Grab a filename. Whitespace at start is skipped, then goes to EOL. */ +static int parse_file_cmd(/*sed_cmd_t *sed_cmd,*/ const char *filecmdstr, char **retval) +{ + int start = 0, idx, hack = 0; + + /* Skip whitespace, then grab filename to end of line */ + while (isspace(filecmdstr[start])) + start++; + idx = start; + while (filecmdstr[idx] && filecmdstr[idx] != '\n') + idx++; + + /* If lines glued together, put backslash back. */ + if (filecmdstr[idx] == '\n') + hack = 1; + if (idx == start) + bb_error_msg_and_die("empty filename"); + *retval = xstrndup(filecmdstr+start, idx-start+hack+1); + if (hack) + (*retval)[idx] = '\\'; + + return idx; +} + +static int parse_subst_cmd(sed_cmd_t *sed_cmd, const char *substr) +{ + int cflags = G.regex_type; + char *match; + int idx; + + /* + * A substitution command should look something like this: + * s/match/replace/ #gIpw + * || | ||| + * mandatory optional + */ + idx = parse_regex_delim(substr, &match, &sed_cmd->string); + + /* determine the number of back references in the match string */ + /* Note: we compute this here rather than in the do_subst_command() + * function to save processor time, at the expense of a little more memory + * (4 bits) per sed_cmd */ + + /* process the flags */ + + sed_cmd->which_match = 1; + while (substr[++idx]) { + /* Parse match number */ + if (isdigit(substr[idx])) { + if (match[0] != '^') { + /* Match 0 treated as all, multiple matches we take the last one. */ + const char *pos = substr + idx; +/* FIXME: error check? */ + sed_cmd->which_match = (unsigned)strtol(substr+idx, (char**) &pos, 10); + idx = pos - substr; + } + continue; + } + /* Skip spaces */ + if (isspace(substr[idx])) continue; + + switch (substr[idx]) { + /* Replace all occurrences */ + case 'g': + if (match[0] != '^') + sed_cmd->which_match = 0; + break; + /* Print pattern space */ + case 'p': + sed_cmd->sub_p = 1; + break; + /* Write to file */ + case 'w': + { + char *temp; + idx += parse_file_cmd(/*sed_cmd,*/ substr+idx, &temp); + break; + } + /* Ignore case (gnu exension) */ + case 'I': + cflags |= REG_ICASE; + break; + /* Comment */ + case '#': + while (substr[++idx]) /*skip all*/; + /* Fall through */ + /* End of command */ + case ';': + case '}': + goto out; + default: + bb_error_msg_and_die("bad option in substitution expression"); + } + } +out: + /* compile the match string into a regex */ + if (*match != '\0') { + /* If match is empty, we use last regex used at runtime */ + sed_cmd->sub_match = xmalloc(sizeof(regex_t)); + xregcomp(sed_cmd->sub_match, match, cflags); + } + free(match); + + return idx; +} + +/* + * Process the commands arguments + */ +static const char *parse_cmd_args(sed_cmd_t *sed_cmd, const char *cmdstr) +{ + /* handle (s)ubstitution command */ + if (sed_cmd->cmd == 's') + cmdstr += parse_subst_cmd(sed_cmd, cmdstr); + /* handle edit cmds: (a)ppend, (i)nsert, and (c)hange */ + else if (strchr("aic", sed_cmd->cmd)) { + if ((sed_cmd->end_line || sed_cmd->end_match) && sed_cmd->cmd != 'c') + bb_error_msg_and_die + ("only a beginning address can be specified for edit commands"); + for (;;) { + if (*cmdstr == '\n' || *cmdstr == '\\') { + cmdstr++; + break; + } else if (isspace(*cmdstr)) + cmdstr++; + else + break; + } + sed_cmd->string = xstrdup(cmdstr); + /* "\anychar" -> "anychar" */ + parse_escapes(sed_cmd->string, sed_cmd->string, strlen(cmdstr), '\0', '\0'); + cmdstr += strlen(cmdstr); + /* handle file cmds: (r)ead */ + } else if (strchr("rw", sed_cmd->cmd)) { + if (sed_cmd->end_line || sed_cmd->end_match) + bb_error_msg_and_die("command only uses one address"); + cmdstr += parse_file_cmd(/*sed_cmd,*/ cmdstr, &sed_cmd->string); + if (sed_cmd->cmd == 'w') { + sed_cmd->sw_file = xfopen_for_write(sed_cmd->string); + sed_cmd->sw_last_char = '\n'; + } + /* handle branch commands */ + } else if (strchr(":btT", sed_cmd->cmd)) { + int length; + + cmdstr = skip_whitespace(cmdstr); + length = strcspn(cmdstr, semicolon_whitespace); + if (length) { + sed_cmd->string = xstrndup(cmdstr, length); + cmdstr += length; + } + } + /* translation command */ + else if (sed_cmd->cmd == 'y') { + char *match, *replace; + int i = cmdstr[0]; + + cmdstr += parse_regex_delim(cmdstr, &match, &replace)+1; + /* \n already parsed, but \delimiter needs unescaping. */ + parse_escapes(match, match, strlen(match), i, i); + parse_escapes(replace, replace, strlen(replace), i, i); + + sed_cmd->string = xzalloc((strlen(match) + 1) * 2); + for (i = 0; match[i] && replace[i]; i++) { + sed_cmd->string[i*2] = match[i]; + sed_cmd->string[i*2+1] = replace[i]; + } + free(match); + free(replace); + } + /* if it wasnt a single-letter command that takes no arguments + * then it must be an invalid command. + */ + else if (strchr("dDgGhHlnNpPqx={}", sed_cmd->cmd) == 0) { + bb_error_msg_and_die("unsupported command %c", sed_cmd->cmd); + } + + /* give back whatever's left over */ + return cmdstr; +} + + +/* Parse address+command sets, skipping comment lines. */ + +static void add_cmd(const char *cmdstr) +{ + sed_cmd_t *sed_cmd; + int temp; + + /* Append this line to any unfinished line from last time. */ + if (G.add_cmd_line) { + char *tp = xasprintf("%s\n%s", G.add_cmd_line, cmdstr); + free(G.add_cmd_line); + cmdstr = G.add_cmd_line = tp; + } + + /* If this line ends with backslash, request next line. */ + temp = strlen(cmdstr); + if (temp && cmdstr[--temp] == '\\') { + if (!G.add_cmd_line) + G.add_cmd_line = xstrdup(cmdstr); + G.add_cmd_line[temp] = '\0'; + return; + } + + /* Loop parsing all commands in this line. */ + while (*cmdstr) { + /* Skip leading whitespace and semicolons */ + cmdstr += strspn(cmdstr, semicolon_whitespace); + + /* If no more commands, exit. */ + if (!*cmdstr) break; + + /* if this is a comment, jump past it and keep going */ + if (*cmdstr == '#') { + /* "#n" is the same as using -n on the command line */ + if (cmdstr[1] == 'n') + G.be_quiet++; + cmdstr = strpbrk(cmdstr, "\n\r"); + if (!cmdstr) break; + continue; + } + + /* parse the command + * format is: [addr][,addr][!]cmd + * |----||-----||-| + * part1 part2 part3 + */ + + sed_cmd = xzalloc(sizeof(sed_cmd_t)); + + /* first part (if present) is an address: either a '$', a number or a /regex/ */ + cmdstr += get_address(cmdstr, &sed_cmd->beg_line, &sed_cmd->beg_match); + + /* second part (if present) will begin with a comma */ + if (*cmdstr == ',') { + int idx; + + cmdstr++; + idx = get_address(cmdstr, &sed_cmd->end_line, &sed_cmd->end_match); + if (!idx) + bb_error_msg_and_die("no address after comma"); + cmdstr += idx; + } + + /* skip whitespace before the command */ + cmdstr = skip_whitespace(cmdstr); + + /* Check for inversion flag */ + if (*cmdstr == '!') { + sed_cmd->invert = 1; + cmdstr++; + + /* skip whitespace before the command */ + cmdstr = skip_whitespace(cmdstr); + } + + /* last part (mandatory) will be a command */ + if (!*cmdstr) + bb_error_msg_and_die("missing command"); + sed_cmd->cmd = *(cmdstr++); + cmdstr = parse_cmd_args(sed_cmd, cmdstr); + + /* Add the command to the command array */ + G.sed_cmd_tail->next = sed_cmd; + G.sed_cmd_tail = G.sed_cmd_tail->next; + } + + /* If we glued multiple lines together, free the memory. */ + free(G.add_cmd_line); + G.add_cmd_line = NULL; +} + +/* Append to a string, reallocating memory as necessary. */ + +#define PIPE_GROW 64 + +static void pipe_putc(char c) +{ + if (G.pipeline.idx == G.pipeline.len) { + G.pipeline.buf = xrealloc(G.pipeline.buf, + G.pipeline.len + PIPE_GROW); + G.pipeline.len += PIPE_GROW; + } + G.pipeline.buf[G.pipeline.idx++] = c; +} + +static void do_subst_w_backrefs(char *line, char *replace) +{ + int i,j; + + /* go through the replacement string */ + for (i = 0; replace[i]; i++) { + /* if we find a backreference (\1, \2, etc.) print the backref'ed * text */ + if (replace[i] == '\\') { + unsigned backref = replace[++i] - '0'; + if (backref <= 9) { + /* print out the text held in G.regmatch[backref] */ + if (G.regmatch[backref].rm_so != -1) { + j = G.regmatch[backref].rm_so; + while (j < G.regmatch[backref].rm_eo) + pipe_putc(line[j++]); + } + continue; + } + /* I _think_ it is impossible to get '\' to be + * the last char in replace string. Thus we dont check + * for replace[i] == NUL. (counterexample anyone?) */ + /* if we find a backslash escaped character, print the character */ + pipe_putc(replace[i]); + continue; + } + /* if we find an unescaped '&' print out the whole matched text. */ + if (replace[i] == '&') { + j = G.regmatch[0].rm_so; + while (j < G.regmatch[0].rm_eo) + pipe_putc(line[j++]); + continue; + } + /* Otherwise just output the character. */ + pipe_putc(replace[i]); + } +} + +static int do_subst_command(sed_cmd_t *sed_cmd, char **line) +{ + char *oldline = *line; + int altered = 0; + unsigned match_count = 0; + regex_t *current_regex; + + /* Handle empty regex. */ + if (sed_cmd->sub_match == NULL) { + current_regex = G.previous_regex_ptr; + if (!current_regex) + bb_error_msg_and_die("no previous regexp"); + } else + G.previous_regex_ptr = current_regex = sed_cmd->sub_match; + + /* Find the first match */ + if (REG_NOMATCH == regexec(current_regex, oldline, 10, G.regmatch, 0)) + return 0; + + /* Initialize temporary output buffer. */ + G.pipeline.buf = xmalloc(PIPE_GROW); + G.pipeline.len = PIPE_GROW; + G.pipeline.idx = 0; + + /* Now loop through, substituting for matches */ + do { + int i; + + /* Work around bug in glibc regexec, demonstrated by: + echo " a.b" | busybox sed 's [^ .]* x g' + The match_count check is so not to break + echo "hi" | busybox sed 's/^/!/g' */ + if (!G.regmatch[0].rm_so && !G.regmatch[0].rm_eo && match_count) { + pipe_putc(*oldline++); + continue; + } + + match_count++; + + /* If we aren't interested in this match, output old line to + end of match and continue */ + if (sed_cmd->which_match + && (sed_cmd->which_match != match_count) + ) { + for (i = 0; i < G.regmatch[0].rm_eo; i++) + pipe_putc(*oldline++); + continue; + } + + /* print everything before the match */ + for (i = 0; i < G.regmatch[0].rm_so; i++) + pipe_putc(oldline[i]); + + /* then print the substitution string */ + do_subst_w_backrefs(oldline, sed_cmd->string); + + /* advance past the match */ + oldline += G.regmatch[0].rm_eo; + /* flag that something has changed */ + altered++; + + /* if we're not doing this globally, get out now */ + if (sed_cmd->which_match) + break; + } while (*oldline && (regexec(current_regex, oldline, 10, G.regmatch, 0) != REG_NOMATCH)); + + /* Copy rest of string into output pipeline */ + + while (*oldline) + pipe_putc(*oldline++); + pipe_putc(0); + + free(*line); + *line = G.pipeline.buf; + return altered; +} + +/* Set command pointer to point to this label. (Does not handle null label.) */ +static sed_cmd_t *branch_to(char *label) +{ + sed_cmd_t *sed_cmd; + + for (sed_cmd = G.sed_cmd_head.next; sed_cmd; sed_cmd = sed_cmd->next) { + if (sed_cmd->cmd == ':' && sed_cmd->string && !strcmp(sed_cmd->string, label)) { + return sed_cmd; + } + } + bb_error_msg_and_die("can't find label for jump to '%s'", label); +} + +static void append(char *s) +{ + llist_add_to_end(&G.append_head, xstrdup(s)); +} + +static void flush_append(void) +{ + char *data; + + /* Output appended lines. */ + while ((data = (char *)llist_pop(&G.append_head))) { + fprintf(G.nonstdout, "%s\n", data); + free(data); + } +} + +static void add_input_file(FILE *file) +{ + G.input_file_list = xrealloc_vector(G.input_file_list, 2, G.input_file_count); + G.input_file_list[G.input_file_count++] = file; +} + +/* Get next line of input from G.input_file_list, flushing append buffer and + * noting if we ran out of files without a newline on the last line we read. + */ +enum { + NO_EOL_CHAR = 1, + LAST_IS_NUL = 2, +}; +static char *get_next_line(char *gets_char) +{ + char *temp = NULL; + int len; + char gc; + + flush_append(); + + /* will be returned if last line in the file + * doesn't end with either '\n' or '\0' */ + gc = NO_EOL_CHAR; + while (G.current_input_file < G.input_file_count) { + FILE *fp = G.input_file_list[G.current_input_file]; + /* Read line up to a newline or NUL byte, inclusive, + * return malloc'ed char[]. length of the chunk read + * is stored in len. NULL if EOF/error */ + temp = bb_get_chunk_from_file(fp, &len); + if (temp) { + /* len > 0 here, it's ok to do temp[len-1] */ + char c = temp[len-1]; + if (c == '\n' || c == '\0') { + temp[len-1] = '\0'; + gc = c; + if (c == '\0') { + int ch = fgetc(fp); + if (ch != EOF) + ungetc(ch, fp); + else + gc = LAST_IS_NUL; + } + } + /* else we put NO_EOL_CHAR into *gets_char */ + break; + + /* NB: I had the idea of peeking next file(s) and returning + * NO_EOL_CHAR only if it is the *last* non-empty + * input file. But there is a case where this won't work: + * file1: "a woo\nb woo" + * file2: "c no\nd no" + * sed -ne 's/woo/bang/p' input1 input2 => "a bang\nb bang" + * (note: *no* newline after "b bang"!) */ + } + /* Close this file and advance to next one */ + fclose(fp); + G.current_input_file++; + } + *gets_char = gc; + return temp; +} + +/* Output line of text. */ +/* Note: + * The tricks with NO_EOL_CHAR and last_puts_char are there to emulate gnu sed. + * Without them, we had this: + * echo -n thingy >z1 + * echo -n again >z2 + * >znull + * sed "s/i/z/" z1 z2 znull | hexdump -vC + * output: + * gnu sed 4.1.5: + * 00000000 74 68 7a 6e 67 79 0a 61 67 61 7a 6e |thzngy.agazn| + * bbox: + * 00000000 74 68 7a 6e 67 79 61 67 61 7a 6e |thzngyagazn| + */ +static void puts_maybe_newline(char *s, FILE *file, char *last_puts_char, char last_gets_char) +{ + char lpc = *last_puts_char; + + /* Need to insert a '\n' between two files because first file's + * last line wasn't terminated? */ + if (lpc != '\n' && lpc != '\0') { + fputc('\n', file); + lpc = '\n'; + } + fputs(s, file); + + /* 'x' - just something which is not '\n', '\0' or NO_EOL_CHAR */ + if (s[0]) + lpc = 'x'; + + /* had trailing '\0' and it was last char of file? */ + if (last_gets_char == LAST_IS_NUL) { + fputc('\0', file); + lpc = 'x'; /* */ + } else + /* had trailing '\n' or '\0'? */ + if (last_gets_char != NO_EOL_CHAR) { + fputc(last_gets_char, file); + lpc = last_gets_char; + } + + if (ferror(file)) { + xfunc_error_retval = 4; /* It's what gnu sed exits with... */ + bb_error_msg_and_die(bb_msg_write_error); + } + *last_puts_char = lpc; +} + +#define sed_puts(s, n) (puts_maybe_newline(s, G.nonstdout, &last_puts_char, n)) + +static int beg_match(sed_cmd_t *sed_cmd, const char *pattern_space) +{ + int retval = sed_cmd->beg_match && !regexec(sed_cmd->beg_match, pattern_space, 0, NULL, 0); + if (retval) + G.previous_regex_ptr = sed_cmd->beg_match; + return retval; +} + +/* Process all the lines in all the files */ + +static void process_files(void) +{ + char *pattern_space, *next_line; + int linenum = 0; + char last_puts_char = '\n'; + char last_gets_char, next_gets_char; + sed_cmd_t *sed_cmd; + int substituted; + + /* Prime the pump */ + next_line = get_next_line(&next_gets_char); + + /* go through every line in each file */ + again: + substituted = 0; + + /* Advance to next line. Stop if out of lines. */ + pattern_space = next_line; + if (!pattern_space) return; + last_gets_char = next_gets_char; + + /* Read one line in advance so we can act on the last line, + * the '$' address */ + next_line = get_next_line(&next_gets_char); + linenum++; + restart: + /* for every line, go through all the commands */ + for (sed_cmd = G.sed_cmd_head.next; sed_cmd; sed_cmd = sed_cmd->next) { + int old_matched, matched; + + old_matched = sed_cmd->in_match; + + /* Determine if this command matches this line: */ + + /* Are we continuing a previous multi-line match? */ + sed_cmd->in_match = sed_cmd->in_match + /* Or is no range necessary? */ + || (!sed_cmd->beg_line && !sed_cmd->end_line + && !sed_cmd->beg_match && !sed_cmd->end_match) + /* Or did we match the start of a numerical range? */ + || (sed_cmd->beg_line > 0 && (sed_cmd->beg_line == linenum)) + /* Or does this line match our begin address regex? */ + || (beg_match(sed_cmd, pattern_space)) + /* Or did we match last line of input? */ + || (sed_cmd->beg_line == -1 && next_line == NULL); + + /* Snapshot the value */ + + matched = sed_cmd->in_match; + + /* Is this line the end of the current match? */ + + if (matched) { + sed_cmd->in_match = !( + /* has the ending line come, or is this a single address command? */ + (sed_cmd->end_line ? + sed_cmd->end_line == -1 ? + !next_line + : (sed_cmd->end_line <= linenum) + : !sed_cmd->end_match + ) + /* or does this line matches our last address regex */ + || (sed_cmd->end_match && old_matched + && (regexec(sed_cmd->end_match, + pattern_space, 0, NULL, 0) == 0)) + ); + } + + /* Skip blocks of commands we didn't match. */ + if (sed_cmd->cmd == '{') { + if (sed_cmd->invert ? matched : !matched) { + while (sed_cmd->cmd != '}') { + sed_cmd = sed_cmd->next; + if (!sed_cmd) + bb_error_msg_and_die("unterminated {"); + } + } + continue; + } + + /* Okay, so did this line match? */ + if (sed_cmd->invert ? !matched : matched) { + /* Update last used regex in case a blank substitute BRE is found */ + if (sed_cmd->beg_match) { + G.previous_regex_ptr = sed_cmd->beg_match; + } + + /* actual sedding */ + switch (sed_cmd->cmd) { + + /* Print line number */ + case '=': + fprintf(G.nonstdout, "%d\n", linenum); + break; + + /* Write the current pattern space up to the first newline */ + case 'P': + { + char *tmp = strchr(pattern_space, '\n'); + + if (tmp) { + *tmp = '\0'; + /* TODO: explain why '\n' below */ + sed_puts(pattern_space, '\n'); + *tmp = '\n'; + break; + } + /* Fall Through */ + } + + /* Write the current pattern space to output */ + case 'p': + /* NB: we print this _before_ the last line + * (of current file) is printed. Even if + * that line is nonterminated, we print + * '\n' here (gnu sed does the same) */ + sed_puts(pattern_space, '\n'); + break; + /* Delete up through first newline */ + case 'D': + { + char *tmp = strchr(pattern_space, '\n'); + + if (tmp) { + tmp = xstrdup(tmp+1); + free(pattern_space); + pattern_space = tmp; + goto restart; + } + } + /* discard this line. */ + case 'd': + goto discard_line; + + /* Substitute with regex */ + case 's': + if (!do_subst_command(sed_cmd, &pattern_space)) + break; + substituted |= 1; + + /* handle p option */ + if (sed_cmd->sub_p) + sed_puts(pattern_space, last_gets_char); + /* handle w option */ + if (sed_cmd->sw_file) + puts_maybe_newline( + pattern_space, sed_cmd->sw_file, + &sed_cmd->sw_last_char, last_gets_char); + break; + + /* Append line to linked list to be printed later */ + case 'a': + append(sed_cmd->string); + break; + + /* Insert text before this line */ + case 'i': + sed_puts(sed_cmd->string, '\n'); + break; + + /* Cut and paste text (replace) */ + case 'c': + /* Only triggers on last line of a matching range. */ + if (!sed_cmd->in_match) + sed_puts(sed_cmd->string, NO_EOL_CHAR); + goto discard_line; + + /* Read file, append contents to output */ + case 'r': + { + FILE *rfile; + + rfile = fopen_for_read(sed_cmd->string); + if (rfile) { + char *line; + + while ((line = xmalloc_fgetline(rfile)) + != NULL) + append(line); + xprint_and_close_file(rfile); + } + + break; + } + + /* Write pattern space to file. */ + case 'w': + puts_maybe_newline( + pattern_space, sed_cmd->sw_file, + &sed_cmd->sw_last_char, last_gets_char); + break; + + /* Read next line from input */ + case 'n': + if (!G.be_quiet) + sed_puts(pattern_space, last_gets_char); + if (next_line) { + free(pattern_space); + pattern_space = next_line; + last_gets_char = next_gets_char; + next_line = get_next_line(&next_gets_char); + substituted = 0; + linenum++; + break; + } + /* fall through */ + + /* Quit. End of script, end of input. */ + case 'q': + /* Exit the outer while loop */ + free(next_line); + next_line = NULL; + goto discard_commands; + + /* Append the next line to the current line */ + case 'N': + { + int len; + /* If no next line, jump to end of script and exit. */ + if (next_line == NULL) { + /* Jump to end of script and exit */ + free(next_line); + next_line = NULL; + goto discard_line; + /* append next_line, read new next_line. */ + } + len = strlen(pattern_space); + pattern_space = realloc(pattern_space, len + strlen(next_line) + 2); + pattern_space[len] = '\n'; + strcpy(pattern_space + len+1, next_line); + last_gets_char = next_gets_char; + next_line = get_next_line(&next_gets_char); + linenum++; + break; + } + + /* Test/branch if substitution occurred */ + case 't': + if (!substituted) break; + substituted = 0; + /* Fall through */ + /* Test/branch if substitution didn't occur */ + case 'T': + if (substituted) break; + /* Fall through */ + /* Branch to label */ + case 'b': + if (!sed_cmd->string) goto discard_commands; + else sed_cmd = branch_to(sed_cmd->string); + break; + /* Transliterate characters */ + case 'y': + { + int i, j; + + for (i = 0; pattern_space[i]; i++) { + for (j = 0; sed_cmd->string[j]; j += 2) { + if (pattern_space[i] == sed_cmd->string[j]) { + pattern_space[i] = sed_cmd->string[j + 1]; + break; + } + } + } + + break; + } + case 'g': /* Replace pattern space with hold space */ + free(pattern_space); + pattern_space = xstrdup(G.hold_space ? G.hold_space : ""); + break; + case 'G': /* Append newline and hold space to pattern space */ + { + int pattern_space_size = 2; + int hold_space_size = 0; + + if (pattern_space) + pattern_space_size += strlen(pattern_space); + if (G.hold_space) + hold_space_size = strlen(G.hold_space); + pattern_space = xrealloc(pattern_space, + pattern_space_size + hold_space_size); + if (pattern_space_size == 2) + pattern_space[0] = 0; + strcat(pattern_space, "\n"); + if (G.hold_space) + strcat(pattern_space, G.hold_space); + last_gets_char = '\n'; + + break; + } + case 'h': /* Replace hold space with pattern space */ + free(G.hold_space); + G.hold_space = xstrdup(pattern_space); + break; + case 'H': /* Append newline and pattern space to hold space */ + { + int hold_space_size = 2; + int pattern_space_size = 0; + + if (G.hold_space) + hold_space_size += strlen(G.hold_space); + if (pattern_space) + pattern_space_size = strlen(pattern_space); + G.hold_space = xrealloc(G.hold_space, + hold_space_size + pattern_space_size); + + if (hold_space_size == 2) + *G.hold_space = 0; + strcat(G.hold_space, "\n"); + if (pattern_space) + strcat(G.hold_space, pattern_space); + + break; + } + case 'x': /* Exchange hold and pattern space */ + { + char *tmp = pattern_space; + pattern_space = G.hold_space ? : xzalloc(1); + last_gets_char = '\n'; + G.hold_space = tmp; + break; + } + } + } + } + + /* + * exit point from sedding... + */ + discard_commands: + /* we will print the line unless we were told to be quiet ('-n') + or if the line was suppressed (ala 'd'elete) */ + if (!G.be_quiet) + sed_puts(pattern_space, last_gets_char); + + /* Delete and such jump here. */ + discard_line: + flush_append(); + free(pattern_space); + + goto again; +} + +/* It is possible to have a command line argument with embedded + * newlines. This counts as multiple command lines. + * However, newline can be escaped: 's/e/z\<newline>z/' + * We check for this. + */ + +static void add_cmd_block(char *cmdstr) +{ + char *sv, *eol; + + cmdstr = sv = xstrdup(cmdstr); + do { + eol = strchr(cmdstr, '\n'); + next: + if (eol) { + /* Count preceding slashes */ + int slashes = 0; + char *sl = eol; + + while (sl != cmdstr && *--sl == '\\') + slashes++; + /* Odd number of preceding slashes - newline is escaped */ + if (slashes & 1) { + overlapping_strcpy(eol - 1, eol); + eol = strchr(eol, '\n'); + goto next; + } + *eol = '\0'; + } + add_cmd(cmdstr); + cmdstr = eol + 1; + } while (eol); + free(sv); +} + +int sed_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int sed_main(int argc UNUSED_PARAM, char **argv) +{ + enum { + OPT_in_place = 1 << 0, + }; + unsigned opt; + llist_t *opt_e, *opt_f; + int status = EXIT_SUCCESS; + + INIT_G(); + + /* destroy command strings on exit */ + if (ENABLE_FEATURE_CLEAN_UP) atexit(sed_free_and_close_stuff); + + /* Lie to autoconf when it starts asking stupid questions. */ + if (argv[1] && !strcmp(argv[1], "--version")) { + puts("This is not GNU sed version 4.0"); + return 0; + } + + /* do normal option parsing */ + opt_e = opt_f = NULL; + opt_complementary = "e::f::" /* can occur multiple times */ + "nn"; /* count -n */ + opt = getopt32(argv, "irne:f:", &opt_e, &opt_f, + &G.be_quiet); /* counter for -n */ + //argc -= optind; + argv += optind; + if (opt & OPT_in_place) { // -i + atexit(cleanup_outname); + } + if (opt & 0x2) G.regex_type |= REG_EXTENDED; // -r + //if (opt & 0x4) G.be_quiet++; // -n + while (opt_e) { // -e + add_cmd_block(llist_pop(&opt_e)); + } + while (opt_f) { // -f + char *line; + FILE *cmdfile; + cmdfile = xfopen_for_read(llist_pop(&opt_f)); + while ((line = xmalloc_fgetline(cmdfile)) != NULL) { + add_cmd(line); + free(line); + } + fclose(cmdfile); + } + /* if we didn't get a pattern from -e or -f, use argv[0] */ + if (!(opt & 0x18)) { + if (!*argv) + bb_show_usage(); + add_cmd_block(*argv++); + } + /* Flush any unfinished commands. */ + add_cmd(""); + + /* By default, we write to stdout */ + G.nonstdout = stdout; + + /* argv[0..(argc-1)] should be names of file to process. If no + * files were specified or '-' was specified, take input from stdin. + * Otherwise, we process all the files specified. */ + if (argv[0] == NULL) { + if (opt & OPT_in_place) + bb_error_msg_and_die(bb_msg_requires_arg, "-i"); + add_input_file(stdin); + process_files(); + } else { + int i; + FILE *file; + + for (i = 0; argv[i]; i++) { + struct stat statbuf; + int nonstdoutfd; + + if (LONE_DASH(argv[i]) && !(opt & OPT_in_place)) { + add_input_file(stdin); + process_files(); + continue; + } + file = fopen_or_warn(argv[i], "r"); + if (!file) { + status = EXIT_FAILURE; + continue; + } + if (!(opt & OPT_in_place)) { + add_input_file(file); + continue; + } + + G.outname = xasprintf("%sXXXXXX", argv[i]); + nonstdoutfd = mkstemp(G.outname); + if (-1 == nonstdoutfd) + bb_perror_msg_and_die("cannot create temp file %s", G.outname); + G.nonstdout = fdopen(nonstdoutfd, "w"); + + /* Set permissions of output file */ + + fstat(fileno(file), &statbuf); + fchmod(nonstdoutfd, statbuf.st_mode); + add_input_file(file); + process_files(); + fclose(G.nonstdout); + + G.nonstdout = stdout; + /* unlink(argv[i]); */ + xrename(G.outname, argv[i]); + free(G.outname); + G.outname = NULL; + } + if (G.input_file_count > G.current_input_file) + process_files(); + } + + return status; +} |