/*
* sed.c - very minimalist version of sed
*
- * Copyright (C) 1999,2000 by Lineo, inc.
- * Written by Mark Whitley <markw@lineo.com>, <markw@enol.com>
+ * Copyright (C) 1999,2000,2001 by Lineo, inc.
+ * Written by Mark Whitley <markw@lineo.com>, <markw@codepoet.org>
*
* 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
- 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
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"
-
+#include <stdlib.h>
+#include "busybox.h"
/* externs */
+extern void xregcomp(regex_t *preg, const char *regex, int cflags);
extern int optind; /* in unistd.h */
extern char *optarg; /* ditto */
/* options */
static int be_quiet = 0;
+
struct sed_cmd {
+
+ /* GENERAL FIELDS */
+ char delimiter; /* The delimiter used to separate regexps */
+
/* 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 == $ */
/* 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? */
+
+ /* SUBSTITUTION COMMAND SPECIFIC FIELDS */
+
+ /* sed -e 's/sub_match/replace/' */
+ regex_t *sub_match;
+ char *replace;
+ 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) */
+ unsigned int sub_p:2; /* sed -e 's/foo/bar/p' (print substitution) */
+
+
+ /* EDIT COMMAND (a,i,c) SPEICIFIC FIELDS */
- /* edit command (a,i,c) speicific field */
char *editline;
};
/*static char *cur_file = NULL;*/ /* file currently being processed XXX: do I need this? */
-#if 0
+#ifdef BB_FEATURE_CLEAN_UP
static void destroy_cmd_strs()
{
if (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_unescaped_slash - walks left to right through a string beginning
- * at a specified index and returns the index of the next unescaped slash.
+ * 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 preceeded by
+ * a backslash ('\').
*/
-static int index_of_next_unescaped_slash(const char *str, int idx)
+static int index_of_next_unescaped_regexp_delim(struct sed_cmd *sed_cmd, const char *str, int idx)
{
- do {
- idx++;
- /* test if we've hit the end */
- if (str[idx] == 0)
- return -1;
- } while (str[idx] != '/' && str[idx - 1] != '\\');
+ for ( ; str[idx]; idx++) {
+ if (str[idx] == sed_cmd->delimiter && str[idx-1] != '\\')
+ return idx;
+ }
- 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)
+static int get_address(struct sed_cmd *sed_cmd, const char *str, int *line, regex_t **regex)
{
char *my_str = strdup(str);
int idx = 0;
idx++;
}
else if (my_str[idx] == '/') {
- idx = index_of_next_unescaped_slash(my_str, idx);
+ idx = index_of_next_unescaped_regexp_delim(sed_cmd, my_str, ++idx);
if (idx == -1)
- fatalError("unterminated match expression\n");
+ error_msg_and_die("unterminated match expression\n");
my_str[idx] = '\0';
*regex = (regex_t *)xmalloc(sizeof(regex_t));
- xregcomp(*regex, my_str+1, REG_NEWLINE);
+ xregcomp(*regex, my_str+1, 0);
idx++; /* so it points to the next character after the last '/' */
}
else {
- errorMsg("get_address: no address found in string\n"
+ error_msg("get_address: no address found in string\n"
"\t(you probably didn't check the string you passed me)\n");
idx = -1;
}
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
- * || | ||
+ * s/match/replace/gIp
+ * || | |||
* 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");
+ /* verify that the 's' is followed by something. That something
+ * (typically a 'slash') is now our regexp delimiter... */
+ if (!substr[++idx])
+ error_msg_and_die("bad format in substitution expression\n");
+ else
+ sed_cmd->delimiter=substr[idx];
/* save the match string */
oldidx = idx+1;
- idx = index_of_next_unescaped_slash(substr, idx);
+ idx = index_of_next_unescaped_regexp_delim(sed_cmd, substr, ++idx);
if (idx == -1)
- fatalError("bad format in substitution expression\n");
+ error_msg_and_die("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);
+ idx = index_of_next_unescaped_regexp_delim(sed_cmd, substr, ++idx);
if (idx == -1)
- fatalError("bad format in substitution expression\n");
+ error_msg_and_die("bad format in substitution expression\n");
sed_cmd->replace = strdup_substr(substr, oldidx, idx);
/* process the flags */
case 'I':
cflags |= REG_ICASE;
break;
+ case 'p':
+ sed_cmd->sub_p = 1;
+ 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");
+ error_msg_and_die("bad option in substitution expression\n");
}
}
out:
- /* compile the regex */
+ /* 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);
*/
if (editstr[1] != '\\' && (editstr[2] != '\n' || editstr[2] != '\r'))
- fatalError("bad format in edit expression\n");
+ error_msg_and_die("bad format in edit expression\n");
/* store the edit line text */
/* make editline big enough to accomodate the extra '\n' we will tack on
/* 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);
+ idx = get_address(sed_cmd, 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);
+ idx += get_address(sed_cmd, &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");
+ error_msg_and_die("missing command\n");
if (!strchr("pdsaic", cmdstr[idx])) /* <-- XXX add new commands here */
- fatalError("invalid command\n");
+ error_msg_and_die("invalid command\n");
sed_cmd->cmd = cmdstr[idx];
/* special-case handling for (s)ubstitution */
/* 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");
+ error_msg_and_die("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
continue;
}
/* grow the array */
- sed_cmds = realloc(sed_cmds, sizeof(struct sed_cmd) * (++ncmds));
+ sed_cmds = xrealloc(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 */
char *line;
char *nextline;
- cmdfile = fopen(filename, "r");
- if (cmdfile == NULL)
- fatalError(strerror(errno));
+ cmdfile = xfopen(filename, "r");
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);
+ line = xrealloc(line, strlen(line) + strlen(nextline) + 1);
strcat(line, nextline);
free(nextline);
}
}
}
+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 a backslash escaped character, print the character */
+ else if (replace[i] == '\\') {
+ ++i;
+ fputc(replace[i], 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)
{
+ char *hackline = (char *)line;
int altered = 0;
+ regmatch_t *regmatch = NULL;
+
+ /* we only proceed if the substitution 'search' expression matches */
+ if (regexec(sed_cmd->sub_match, line, 0, NULL, 0) == REG_NOMATCH)
+ return 0;
+
+ /* whaddaya know, it matched. get the number of back references */
+ regmatch = xmalloc(sizeof(regmatch_t) * (sed_cmd->num_backrefs+1));
- /* we only substitute if the substitution 'search' expression matches */
- if (regexec(sed_cmd->sub_match, line, 0, NULL, 0) == 0) {
- regmatch_t regmatch;
+ /* and now, as long as we've got a line to try matching and if we can match
+ * the search string, we make substitutions */
+ while (*hackline && (regexec(sed_cmd->sub_match, hackline,
+ sed_cmd->num_backrefs+1, regmatch, 0) == 0) ) {
int i;
- char *ptr = (char *)line;
-
- while (*ptr) {
- /* if we can match the search string... */
- if (regexec(sed_cmd->sub_match, ptr, 1, ®match, 0) == 0) {
- /* print everything before the match, */
- for (i = 0; i < regmatch.rm_so; i++)
- fputc(ptr[i], stdout);
- /* then print the substitution in its place */
- fputs(sed_cmd->replace, stdout);
- /* then advance past the match */
- ptr += regmatch.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);
+ /* print everything before the match */
+ for (i = 0; i < regmatch[0].rm_so; i++)
+ fputc(hackline[i], stdout);
+
+ /* then print the substitution string */
+ print_subst_w_backrefs(hackline, sed_cmd->replace, regmatch);
+
+ /* advance past the match */
+ hackline += regmatch[0].rm_eo;
+ /* flag that something has changed */
+ altered++;
+
+ /* if we're not doing this globally, get out now */
+ if (!sed_cmd->sub_g)
+ break;
}
+ /* if there's anything left of the line, print it */
+ if (*hackline)
+ fputs(hackline, stdout);
+
+ /* cleanup */
+ free(regmatch);
+
return altered;
}
break;
case 's':
- altered = do_subst_command(sed_cmd, line);
+
+ /*
+ * Some special cases for 's' printing to make it compliant with
+ * GNU sed printing behavior (aka "The -n | s///p Matrix"):
+ *
+ * -n ONLY = never print anything regardless of any successful
+ * substitution
+ *
+ * s///p ONLY = always print successful substitutions, even if
+ * the line is going to be printed anyway (line will be printed
+ * twice).
+ *
+ * -n AND s///p = print ONLY a successful substitution ONE TIME;
+ * no other lines are printed - this is the reason why the 'p'
+ * flag exists in the first place.
+ */
+
+ /* if the user specified that they didn't want anything printed (i.e. a -n
+ * flag and no 'p' flag after the s///), then there's really no point doing
+ * anything here. */
+ if (be_quiet && !sed_cmd->sub_p)
+ break;
+
+ /* we print the line once, unless we were told to be quiet */
+ if (!be_quiet)
+ altered = do_subst_command(sed_cmd, line);
+
+ /* we also print the line if we were given the 'p' flag
+ * (this is quite possibly the second printing) */
+ if (sed_cmd->sub_p)
+ altered = do_subst_command(sed_cmd, line);
+
break;
case 'a':
}
/* 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)
+ else if (sed_cmds[i].beg_line > 0 && sed_cmds[i].end_line != 0) {
+ if (linenum >= sed_cmds[i].beg_line &&
+ (sed_cmds[i].end_line == -1 || linenum <= sed_cmds[i].end_line))
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) */
+ * line was altered (via a 'd'elete or 's'ubstitution), in which case
+ * the altered line was already printed */
if (!be_quiet && !line_altered)
fputs(line, stdout);
{
int opt;
- /* do special-case option parsing */
- if (argv[1] && (strcmp(argv[1], "--help") == 0))
- usage(sed_usage);
-
-#if 0
+#ifdef BB_FEATURE_CLEAN_UP
/* destroy command strings on exit */
- if (atexit(destroy_cmd_strs) == -1) {
- perror("sed");
- exit(1);
- }
+ if (atexit(destroy_cmd_strs) == -1)
+ perror_msg_and_die("atexit");
#endif
/* do normal option parsing */
- while ((opt = getopt(argc, argv, "Vhne:f:")) > 0) {
+ while ((opt = getopt(argc, argv, "hne:f:")) > 0) {
switch (opt) {
- case 'V':
- printf("BusyBox v%s (%s)\n", BB_VER, BB_BT);
- exit(0);
- break;
case 'h':
usage(sed_usage);
break;
for (i = optind; i < argc; i++) {
file = fopen(argv[i], "r");
if (file == NULL) {
- errorMsg("%s: %s\n", argv[i], strerror(errno));
+ perror_msg("%s", argv[i]);
} else {
process_file(file);
fclose(file);
projects / oweals / busybox.git / blobdiff