| /* |
| * sed.c - very minimalist version of sed |
| * |
| * Copyright (C) 1999,2000 by Lineo, inc. |
| * Written by Mark Whitley <markw@lineo.com>, <markw@enol.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| * |
| */ |
| |
| /* |
| 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 |
| - backreferences in substitution expressions (\1, \2...\9) |
| |
| (Note: Specifying an address (range) to match is *optional*; commands |
| default to the whole pattern space if no specific address match was |
| requested.) |
| |
| Unsupported features: |
| |
| - transliteration (y/source-chars/dest-chars/) (use 'tr') |
| - no support for characters other than the '/' character for regex matches |
| - no pattern space hold space storing / swapping (x, etc.) |
| - no labels / branching (: label, b, t, and friends) |
| - and lots, lots more. |
| |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> /* for realloc() */ |
| #include <unistd.h> /* for getopt() */ |
| #include <regex.h> |
| #include <string.h> /* for strdup() */ |
| #include <errno.h> |
| #include <ctype.h> /* for isspace() */ |
| #include "internal.h" |
| |
| #define bb_need_full_version |
| #define BB_DECLARE_EXTERN |
| #include "messages.c" |
| |
| /* externs */ |
| extern int optind; /* in unistd.h */ |
| extern char *optarg; /* ditto */ |
| |
| /* options */ |
| static int be_quiet = 0; |
| |
| struct sed_cmd { |
| |
| /* address storage */ |
| int beg_line; /* 'sed 1p' 0 == no begining line, apply commands to all lines */ |
| int end_line; /* 'sed 1,3p' 0 == no end line, use only beginning. -1 == $ */ |
| regex_t *beg_match; /* sed -e '/match/cmd' */ |
| regex_t *end_match; /* sed -e '/match/,/end_match/cmd' */ |
| |
| /* the command */ |
| char cmd; /* p,d,s (add more at your leisure :-) */ |
| |
| /* substitution command specific fields */ |
| regex_t *sub_match; /* sed -e 's/sub_match/replace/' */ |
| char *replace; /* sed -e 's/sub_match/replace/' XXX: who will hold the \1 \2 \3s? */ |
| unsigned int num_backrefs:4; /* how many back references (\1..\9) */ |
| /* Note: GNU/POSIX sed does not save more than nine backrefs, so |
| * we only use 4 bits to hold the number */ |
| unsigned int sub_g:1; /* sed -e 's/foo/bar/g' (global) */ |
| |
| /* edit command (a,i,c) speicific field */ |
| char *editline; |
| }; |
| |
| /* globals */ |
| static struct sed_cmd *sed_cmds = NULL; /* growable arrary holding a sequence of sed cmds */ |
| static int ncmds = 0; /* number of sed commands */ |
| |
| /*static char *cur_file = NULL;*/ /* file currently being processed XXX: do I need this? */ |
| |
| #if 0 |
| static void destroy_cmd_strs() |
| { |
| if (sed_cmds == NULL) |
| return; |
| |
| /* destroy all the elements in the array */ |
| while (--ncmds >= 0) { |
| |
| if (sed_cmds[ncmds].beg_match) { |
| regfree(sed_cmds[ncmds].beg_match); |
| free(sed_cmds[ncmds].beg_match); |
| } |
| if (sed_cmds[ncmds].end_match) { |
| regfree(sed_cmds[ncmds].end_match); |
| free(sed_cmds[ncmds].end_match); |
| } |
| if (sed_cmds[ncmds].sub_match) { |
| regfree(sed_cmds[ncmds].sub_match); |
| free(sed_cmds[ncmds].sub_match); |
| } |
| if (sed_cmds[ncmds].replace) |
| free(sed_cmds[ncmds].replace); |
| } |
| |
| /* destroy the array */ |
| free(sed_cmds); |
| sed_cmds = NULL; |
| } |
| #endif |
| |
| #if 0 |
| /* |
| * trim_str - trims leading and trailing space from a string |
| * |
| * Note: This returns a malloc'ed string so you must store and free it |
| * XXX: This should be in the utility.c file. |
| * XXX: This is now obsolete. Maybe it belongs nowhere. |
| */ |
| static char *trim_str(const char *str) |
| { |
| int i; |
| char *retstr = strdup(str); |
| |
| /* trim leading whitespace */ |
| memmove(retstr, &retstr[strspn(retstr, " \n\t\v")], strlen(retstr)); |
| |
| /* trim trailing whitespace */ |
| i = strlen(retstr) - 1; |
| while (isspace(retstr[i])) |
| i--; |
| retstr[++i] = 0; |
| |
| /* Aside: |
| * |
| * you know, a strrspn() would really be nice cuz then we could say: |
| * |
| * retstr[strrspn(retstr, " \n\t\v") + 1] = 0; |
| */ |
| |
| return retstr; |
| } |
| #endif |
| |
| #if 0 |
| /* |
| * strrspn - works just like strspn() but goes from right to left instead of |
| * left to right |
| */ |
| static size_t strrspn(const char *s, const char *accept) |
| { |
| size_t i = strlen(s); |
| |
| while (strchr(accept, s[--i])) |
| ; |
| |
| return i; |
| } |
| #endif |
| |
| /* |
| * index_of_next_unescaped_slash - walks left to right through a string |
| * beginning at a specified index and returns the index of the next forward |
| * slash ('/') not preceeded by a backslash ('\'). |
| */ |
| static int index_of_next_unescaped_slash(const char *str, int idx) |
| { |
| for ( ; str[idx]; idx++) { |
| if (str[idx] == '/' && str[idx-1] != '\\') |
| return idx; |
| } |
| |
| /* if we make it to here, we've hit the end of the string */ |
| return -1; |
| } |
| |
| /* |
| * returns the index in the string just past where the address ends. |
| */ |
| static int get_address(const char *str, int *line, regex_t **regex) |
| { |
| char *my_str = strdup(str); |
| int idx = 0; |
| |
| if (isdigit(my_str[idx])) { |
| do { |
| idx++; |
| } while (isdigit(my_str[idx])); |
| my_str[idx] = 0; |
| *line = atoi(my_str); |
| } |
| else if (my_str[idx] == '$') { |
| *line = -1; |
| idx++; |
| } |
| else if (my_str[idx] == '/') { |
| idx = index_of_next_unescaped_slash(my_str, ++idx); |
| if (idx == -1) |
| fatalError("unterminated match expression\n"); |
| my_str[idx] = '\0'; |
| *regex = (regex_t *)xmalloc(sizeof(regex_t)); |
| xregcomp(*regex, my_str+1, REG_NEWLINE); |
| idx++; /* so it points to the next character after the last '/' */ |
| } |
| else { |
| errorMsg("get_address: no address found in string\n" |
| "\t(you probably didn't check the string you passed me)\n"); |
| idx = -1; |
| } |
| |
| free(my_str); |
| return idx; |
| } |
| |
| static char *strdup_substr(const char *str, int start, int end) |
| { |
| int size = end - start + 1; |
| char *newstr = xmalloc(size); |
| memcpy(newstr, str+start, size-1); |
| newstr[size-1] = '\0'; |
| return newstr; |
| } |
| |
| static int parse_subst_cmd(struct sed_cmd *sed_cmd, const char *substr) |
| { |
| int oldidx, cflags = REG_NEWLINE; |
| char *match; |
| int idx = 0; |
| int j; |
| |
| /* |
| * the string that gets passed to this function should look like this: |
| * s/match/replace/gI |
| * || | || |
| * mandatory optional |
| * |
| * (all three of the '/' slashes are mandatory) |
| */ |
| |
| /* verify that the 's' is followed by a 'slash' */ |
| if (substr[++idx] != '/') |
| fatalError("bad format in substitution expression\n"); |
| |
| /* save the match string */ |
| oldidx = idx+1; |
| idx = index_of_next_unescaped_slash(substr, ++idx); |
| if (idx == -1) |
| fatalError("bad format in substitution expression\n"); |
| match = strdup_substr(substr, oldidx, idx); |
| |
| /* 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 */ |
| |
| /* sed_cmd->num_backrefs = 0; */ /* XXX: not needed? --apparently not */ |
| for (j = 0; match[j]; j++) { |
| /* GNU/POSIX sed does not save more than nine backrefs */ |
| if (match[j] == '\\' && match[j+1] == '(' && sed_cmd->num_backrefs < 9) |
| sed_cmd->num_backrefs++; |
| } |
| |
| /* save the replacement string */ |
| oldidx = idx+1; |
| idx = index_of_next_unescaped_slash(substr, ++idx); |
| if (idx == -1) |
| fatalError("bad format in substitution expression\n"); |
| sed_cmd->replace = strdup_substr(substr, oldidx, idx); |
| |
| /* process the flags */ |
| while (substr[++idx]) { |
| switch (substr[idx]) { |
| case 'g': |
| sed_cmd->sub_g = 1; |
| break; |
| case 'I': |
| cflags |= REG_ICASE; |
| break; |
| default: |
| /* any whitespace or semicolon trailing after a s/// is ok */ |
| if (strchr("; \t\v\n\r", substr[idx])) |
| goto out; |
| /* else */ |
| fatalError("bad option in substitution expression\n"); |
| } |
| } |
| |
| out: |
| /* compile the match string into a regex */ |
| sed_cmd->sub_match = (regex_t *)xmalloc(sizeof(regex_t)); |
| xregcomp(sed_cmd->sub_match, match, cflags); |
| free(match); |
| |
| return idx; |
| } |
| |
| static int parse_edit_cmd(struct sed_cmd *sed_cmd, const char *editstr) |
| { |
| int idx = 0; |
| int slashes_eaten = 0; |
| char *ptr; /* shorthand */ |
| |
| /* |
| * the string that gets passed to this function should look like this: |
| * |
| * need one of these |
| * | |
| * | this backslash (immediately following the edit command) is mandatory |
| * | | |
| * [aic]\ |
| * TEXT1\ |
| * TEXT2\ |
| * TEXTN |
| * |
| * as soon as we hit a TEXT line that has no trailing '\', we're done. |
| * this means a command like: |
| * |
| * i\ |
| * INSERTME |
| * |
| * is a-ok. |
| * |
| */ |
| |
| if (editstr[1] != '\\' && (editstr[2] != '\n' || editstr[2] != '\r')) |
| fatalError("bad format in edit expression\n"); |
| |
| /* store the edit line text */ |
| /* make editline big enough to accomodate the extra '\n' we will tack on |
| * to the end */ |
| sed_cmd->editline = xmalloc(strlen(&editstr[3]) + 2); |
| strcpy(sed_cmd->editline, &editstr[3]); |
| ptr = sed_cmd->editline; |
| |
| /* now we need to go through * and: s/\\[\r\n]$/\n/g on the edit line */ |
| while (ptr[idx]) { |
| while (ptr[idx] != '\\' && (ptr[idx+1] != '\n' || ptr[idx+1] != '\r')) { |
| idx++; |
| if (!ptr[idx]) { |
| goto out; |
| } |
| } |
| /* move the newline over the '\' before it (effectively eats the '\') */ |
| memmove(&ptr[idx], &ptr[idx+1], strlen(&ptr[idx+1])); |
| ptr[strlen(ptr)-1] = 0; |
| slashes_eaten++; |
| /* substitue \r for \n if needed */ |
| if (ptr[idx] == '\r') |
| ptr[idx] = '\n'; |
| } |
| |
| out: |
| ptr[idx] = '\n'; |
| ptr[idx+1] = 0; |
| |
| /* this accounts for discrepancies between the modified string and the |
| * original string passed in to this function */ |
| idx += slashes_eaten; |
| |
| /* this accounts for the fact that A) we started at index 3, not at index |
| * 0 and B) that we added an extra '\n' at the end (if you think the next |
| * line should read 'idx += 4' remember, arrays are zero-based) */ |
| |
| idx += 3; |
| |
| return idx; |
| } |
| |
| static char *parse_cmd_str(struct sed_cmd *sed_cmd, const char *cmdstr) |
| { |
| int idx = 0; |
| |
| /* parse the command |
| * format is: [addr][,addr]cmd |
| * |----||-----||-| |
| * part1 part2 part3 |
| */ |
| |
| |
| /* first part (if present) is an address: either a number or a /regex/ */ |
| if (isdigit(cmdstr[idx]) || cmdstr[idx] == '/') |
| idx = get_address(cmdstr, &sed_cmd->beg_line, &sed_cmd->beg_match); |
| |
| /* second part (if present) will begin with a comma */ |
| if (cmdstr[idx] == ',') |
| idx += get_address(&cmdstr[++idx], &sed_cmd->end_line, &sed_cmd->end_match); |
| |
| /* last part (mandatory) will be a command */ |
| if (cmdstr[idx] == '\0') |
| fatalError("missing command\n"); |
| if (!strchr("pdsaic", cmdstr[idx])) /* <-- XXX add new commands here */ |
| fatalError("invalid command\n"); |
| sed_cmd->cmd = cmdstr[idx]; |
| |
| /* special-case handling for (s)ubstitution */ |
| if (sed_cmd->cmd == 's') { |
| idx += parse_subst_cmd(sed_cmd, &cmdstr[idx]); |
| } |
| /* special-case handling for (a)ppend, (i)nsert, and (c)hange */ |
| else if (strchr("aic", cmdstr[idx])) { |
| if (sed_cmd->end_line || sed_cmd->end_match) |
| fatalError("only a beginning address can be specified for edit commands\n"); |
| idx += parse_edit_cmd(sed_cmd, &cmdstr[idx]); |
| } |
| /* if it was a single-letter command (such as 'p' or 'd') we need to |
| * increment the index past that command */ |
| else |
| idx++; |
| |
| /* give back whatever's left over */ |
| return (char *)&cmdstr[idx]; |
| } |
| |
| static void add_cmd_str(const char *cmdstr) |
| { |
| char *mystr = (char *)cmdstr; |
| |
| do { |
| |
| /* trim leading whitespace and semicolons */ |
| memmove(mystr, &mystr[strspn(mystr, "; \n\r\t\v")], strlen(mystr)); |
| /* if we ate the whole thing, that means there was just trailing |
| * whitespace or a final / no-op semicolon. either way, get out */ |
| if (strlen(mystr) == 0) |
| return; |
| /* if this is a comment, jump past it and keep going */ |
| if (mystr[0] == '#') { |
| mystr = strpbrk(mystr, ";\n\r"); |
| continue; |
| } |
| /* grow the array */ |
| sed_cmds = realloc(sed_cmds, sizeof(struct sed_cmd) * (++ncmds)); |
| /* zero new element */ |
| memset(&sed_cmds[ncmds-1], 0, sizeof(struct sed_cmd)); |
| /* load command string into new array element, get remainder */ |
| mystr = parse_cmd_str(&sed_cmds[ncmds-1], mystr); |
| |
| } while (mystr && strlen(mystr)); |
| } |
| |
| |
| static void load_cmd_file(char *filename) |
| { |
| FILE *cmdfile; |
| char *line; |
| char *nextline; |
| |
| cmdfile = fopen(filename, "r"); |
| if (cmdfile == NULL) |
| fatalError(strerror(errno)); |
| |
| while ((line = get_line_from_file(cmdfile)) != NULL) { |
| /* if a line ends with '\' it needs the next line appended to it */ |
| while (line[strlen(line)-2] == '\\' && |
| (nextline = get_line_from_file(cmdfile)) != NULL) { |
| line = realloc(line, strlen(line) + strlen(nextline) + 1); |
| strcat(line, nextline); |
| free(nextline); |
| } |
| /* eat trailing newline (if any) --if I don't do this, edit commands |
| * (aic) will print an extra newline */ |
| if (line[strlen(line)-1] == '\n') |
| line[strlen(line)-1] = 0; |
| add_cmd_str(line); |
| free(line); |
| } |
| } |
| |
| static void print_subst_w_backrefs(const char *line, const char *replace, regmatch_t *regmatch) |
| { |
| int i; |
| |
| /* 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] == '\\' && isdigit(replace[i+1])) { |
| int j; |
| char tmpstr[2]; |
| int backref; |
| ++i; /* i now indexes the backref number, instead of the leading slash */ |
| tmpstr[0] = replace[i]; |
| tmpstr[1] = 0; |
| backref = atoi(tmpstr); |
| /* print out the text held in regmatch[backref] */ |
| for (j = regmatch[backref].rm_so; j < regmatch[backref].rm_eo; j++) |
| fputc(line[j], stdout); |
| } |
| |
| /* if we find an unescaped '&' print out the whole matched text. |
| * fortunately, regmatch[0] contains the indicies to the whole matched |
| * expression (kinda seems like it was designed for just such a |
| * purpose...) */ |
| else if (replace[i] == '&' && replace[i-1] != '\\') { |
| int j; |
| for (j = regmatch[0].rm_so; j < regmatch[0].rm_eo; j++) |
| fputc(line[j], stdout); |
| } |
| /* nothing special, just print this char of the replacement string to stdout */ |
| else |
| fputc(replace[i], stdout); |
| } |
| } |
| |
| static int do_subst_command(const struct sed_cmd *sed_cmd, const char *line) |
| { |
| int altered = 0; |
| |
| /* we only substitute if the substitution 'search' expression matches */ |
| if (regexec(sed_cmd->sub_match, line, 0, NULL, 0) == 0) { |
| regmatch_t *regmatch = xmalloc(sizeof(regmatch_t) * (sed_cmd->num_backrefs+1)); |
| int i; |
| char *ptr = (char *)line; |
| |
| while (*ptr) { |
| /* if we can match the search string... */ |
| if (regexec(sed_cmd->sub_match, ptr, sed_cmd->num_backrefs+1, regmatch, 0) == 0) { |
| /* print everything before the match, */ |
| for (i = 0; i < regmatch[0].rm_so; i++) |
| fputc(ptr[i], stdout); |
| |
| /* then print the substitution in its place */ |
| print_subst_w_backrefs(ptr, sed_cmd->replace, regmatch); |
| |
| /* then advance past the match */ |
| ptr += regmatch[0].rm_eo; |
| |
| /* and flag that something has changed */ |
| altered++; |
| |
| /* if we're not doing this globally... */ |
| if (!sed_cmd->sub_g) |
| break; |
| } |
| /* if we COULD NOT match the search string (meaning we've gone past |
| * all previous instances), get out */ |
| else |
| break; |
| } |
| |
| /* is there anything left to print? */ |
| if (*ptr) |
| fputs(ptr, stdout); |
| |
| /* cleanup */ |
| free(regmatch); |
| } |
| |
| return altered; |
| } |
| |
| static int do_sed_command(const struct sed_cmd *sed_cmd, const char *line) |
| { |
| int altered = 0; |
| |
| switch (sed_cmd->cmd) { |
| |
| case 'p': |
| fputs(line, stdout); |
| break; |
| |
| case 'd': |
| altered++; |
| break; |
| |
| case 's': |
| altered = do_subst_command(sed_cmd, line); |
| break; |
| |
| case 'a': |
| fputs(line, stdout); |
| fputs(sed_cmd->editline, stdout); |
| altered++; |
| break; |
| |
| case 'i': |
| fputs(sed_cmd->editline, stdout); |
| break; |
| |
| case 'c': |
| fputs(sed_cmd->editline, stdout); |
| altered++; |
| break; |
| } |
| |
| return altered; |
| } |
| |
| static void process_file(FILE *file) |
| { |
| char *line = NULL; |
| static int linenum = 0; /* GNU sed does not restart counting lines at EOF */ |
| unsigned int still_in_range = 0; |
| int line_altered; |
| int i; |
| |
| /* go through every line in the file */ |
| while ((line = get_line_from_file(file)) != NULL) { |
| |
| linenum++; |
| line_altered = 0; |
| |
| /* for every line, go through all the commands */ |
| for (i = 0; i < ncmds; i++) { |
| |
| /* are we acting on a range of matched lines? */ |
| if (sed_cmds[i].beg_match && sed_cmds[i].end_match) { |
| if (still_in_range || regexec(sed_cmds[i].beg_match, line, 0, NULL, 0) == 0) { |
| line_altered += do_sed_command(&sed_cmds[i], line); |
| still_in_range = 1; |
| if (regexec(sed_cmds[i].end_match, line, 0, NULL, 0) == 0) |
| still_in_range = 0; |
| } |
| } |
| |
| /* are we trying to match a single line? */ |
| else if (sed_cmds[i].beg_match) { |
| if (regexec(sed_cmds[i].beg_match, line, 0, NULL, 0) == 0) |
| line_altered += do_sed_command(&sed_cmds[i], line); |
| } |
| |
| /* are we acting on a range of line numbers? */ |
| else if (sed_cmds[i].beg_line > 0 && sed_cmds[i].end_line > 0) { |
| if (linenum >= sed_cmds[i].beg_line && linenum <= sed_cmds[i].end_line) |
| line_altered += do_sed_command(&sed_cmds[i], line); |
| } |
| |
| /* are we acting on a specified line number */ |
| else if (sed_cmds[i].beg_line > 0) { |
| if (linenum == sed_cmds[i].beg_line) |
| line_altered += do_sed_command(&sed_cmds[i], line); |
| } |
| |
| /* not acting on matches or line numbers. act on every line */ |
| else |
| line_altered += do_sed_command(&sed_cmds[i], line); |
| |
| } |
| |
| /* we will print the line unless we were told to be quiet or if the |
| * line was altered (via a 'd'elete or 's'ubstitution) */ |
| if (!be_quiet && !line_altered) |
| fputs(line, stdout); |
| |
| free(line); |
| } |
| } |
| |
| extern int sed_main(int argc, char **argv) |
| { |
| int opt; |
| |
| #if 0 |
| /* destroy command strings on exit */ |
| if (atexit(destroy_cmd_strs) == -1) { |
| perror("sed"); |
| exit(1); |
| } |
| #endif |
| |
| /* do normal option parsing */ |
| while ((opt = getopt(argc, argv, "hne:f:")) > 0) { |
| switch (opt) { |
| case 'h': |
| usage(sed_usage); |
| break; |
| case 'n': |
| be_quiet++; |
| break; |
| case 'e': |
| add_cmd_str(optarg); |
| break; |
| case 'f': |
| load_cmd_file(optarg); |
| break; |
| } |
| } |
| |
| /* if we didn't get a pattern from a -e and no command file was specified, |
| * argv[optind] should be the pattern. no pattern, no worky */ |
| if (ncmds == 0) { |
| if (argv[optind] == NULL) |
| usage(sed_usage); |
| else { |
| add_cmd_str(argv[optind]); |
| optind++; |
| } |
| } |
| |
| |
| /* argv[(optind)..(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[optind] == NULL || (strcmp(argv[optind], "-") == 0)) { |
| process_file(stdin); |
| } |
| else { |
| int i; |
| FILE *file; |
| for (i = optind; i < argc; i++) { |
| file = fopen(argv[i], "r"); |
| if (file == NULL) { |
| errorMsg("%s: %s\n", argv[i], strerror(errno)); |
| } else { |
| process_file(file); |
| fclose(file); |
| } |
| } |
| } |
| |
| return 0; |
| } |