hush/sed.c
Erik Andersen e916d24805 Fixed a bug where "sed 's/foo/bar/g'" (i.e. a script w/o a -e)
would go into an infinite loop.
 -Erik
2000-03-06 19:20:35 +00:00

357 lines
7.3 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini sed implementation for busybox
*
*
* Copyright (C) 1999 by Lineo, inc.
* Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
*
* Modifications for addresses and append command have been
* written by Marco Pantaleoni <panta@prosa.it>, <panta@elasticworld.org>
* and are:
* Copyright (C) 1999 Marco Pantaleoni.
*
* 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
*
*/
#include "internal.h"
#include "regexp.h"
#include <stdio.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <time.h>
#include <ctype.h>
static const char sed_usage[] =
"sed [-n] -e script [file...]\n\n"
"Allowed sed scripts come in the following form:\n"
"\t'ADDR [!] COMMAND'\n\n"
"\twhere address ADDR can be:\n"
"\t NUMBER Match specified line number\n"
"\t $ Match last line\n"
"\t /REGEXP/ Match specified regexp\n"
"\t (! inverts the meaning of the match)\n\n"
"\tand COMMAND can be:\n"
"\t s/regexp/replacement/[igp]\n"
"\t which attempt to match regexp against the pattern space\n"
"\t and if successful replaces the matched portion with replacement.\n\n"
"\t aTEXT\n"
"\t which appends TEXT after the pattern space\n"
"Options:\n"
"-e\tadd the script to the commands to be executed\n"
"-n\tsuppress automatic printing of pattern space\n\n"
#if defined BB_REGEXP
"This version of sed matches full regular expresions.\n";
#else
"This version of sed matches strings (not full regular expresions).\n";
#endif
/* Flags & variables */
typedef enum { f_none, f_replace, f_append } sed_function;
#define NO_LINE -2
#define LAST_LINE -1
static int addr_line = NO_LINE;
static char *addr_pattern = NULL;
static int negated = 0;
#define SKIPSPACES(p) do { while (isspace(*(p))) (p)++; } while (0)
#define BUFSIZE 1024
static inline int at_last(FILE * fp)
{
int res = 0;
if (feof(fp))
return 1;
else {
int ch;
if ((ch = fgetc(fp)) == EOF)
res++;
ungetc(ch, fp);
}
return res;
}
static void do_sed_repl(FILE * fp, char *needle, char *newNeedle,
int ignoreCase, int printFlag, int quietFlag)
{
int foundOne = FALSE;
char haystack[BUFSIZE];
int line = 1, doit;
while (fgets(haystack, BUFSIZE - 1, fp)) {
doit = 0;
if (addr_pattern) {
doit = !find_match(haystack, addr_pattern, FALSE);
} else if (addr_line == NO_LINE)
doit = 1;
else if (addr_line == LAST_LINE) {
if (at_last(fp))
doit = 1;
} else {
if (line == addr_line)
doit = 1;
}
if (negated)
doit = 1 - doit;
if (doit) {
foundOne =
replace_match(haystack, needle, newNeedle, ignoreCase);
if (foundOne == TRUE && printFlag == TRUE) {
fprintf(stdout, haystack);
}
}
if (quietFlag == FALSE) {
fprintf(stdout, haystack);
}
line++;
}
}
static void do_sed_append(FILE * fp, char *appendline, int quietFlag)
{
char buffer[BUFSIZE];
int line = 1, doit;
while (fgets(buffer, BUFSIZE - 1, fp)) {
doit = 0;
if (addr_pattern) {
doit = !find_match(buffer, addr_pattern, FALSE);
} else if (addr_line == NO_LINE)
doit = 1;
else if (addr_line == LAST_LINE) {
if (at_last(fp))
doit = 1;
} else {
if (line == addr_line)
doit = 1;
}
if (negated)
doit = 1 - doit;
if (quietFlag == FALSE) {
fprintf(stdout, buffer);
}
if (doit) {
fputs(appendline, stdout);
fputc('\n', stdout);
}
line++;
}
}
extern int sed_main(int argc, char **argv)
{
FILE *fp;
char *needle = NULL, *newNeedle = NULL;
char *name;
char *cp;
int ignoreCase = FALSE;
int printFlag = FALSE;
int quietFlag = FALSE;
int stopNow;
char *line_s = NULL, saved;
char *appendline = NULL;
char *pos;
sed_function sed_f = f_none;
argc--;
argv++;
if (argc < 1) {
usage(sed_usage);
}
while (argc > 1) {
if (**argv != '-')
usage(sed_usage);
argc--;
cp = *argv++;
stopNow = FALSE;
while (*++cp && stopNow == FALSE) {
switch (*cp) {
case 'n':
quietFlag = TRUE;
break;
case 'e':
if (*(cp + 1) == 0 && --argc < 0) {
usage(sed_usage);
}
if (*++cp != 's')
cp = *argv++;
/* Read address if present */
SKIPSPACES(cp);
if (*cp == '$') {
addr_line = LAST_LINE;
cp++;
} else {
if (isdigit(*cp)) { /* LINE ADDRESS */
line_s = cp;
while (isdigit(*cp))
cp++;
if (cp > line_s) {
/* numeric line */
saved = *cp;
*cp = '\0';
addr_line = atoi(line_s);
*cp = saved;
}
} else if (*cp == '/') { /* PATTERN ADDRESS */
pos = addr_pattern = cp + 1;
pos = strchr(pos, '/');
if (!pos)
usage(sed_usage);
*pos = '\0';
cp = pos + 1;
}
}
SKIPSPACES(cp);
if (*cp == '!') {
negated++;
cp++;
}
/* Read command */
SKIPSPACES(cp);
switch (*cp) {
case 's': /* REPLACE */
if (strlen(cp) <= 3 || *(cp + 1) != '/')
break;
sed_f = f_replace;
pos = needle = cp + 2;
for (;;) {
pos = strchr(pos, '/');
if (pos == NULL) {
usage(sed_usage);
}
if (*(pos - 1) == '\\') {
pos++;
continue;
}
break;
}
*pos = 0;
newNeedle = ++pos;
for (;;) {
pos = strchr(pos, '/');
if (pos == NULL) {
usage(sed_usage);
}
if (*(pos - 1) == '\\') {
pos++;
continue;
}
break;
}
*pos = 0;
if (pos + 2 != 0) {
while (*++pos) {
switch (*pos) {
case 'i':
ignoreCase = TRUE;
break;
case 'p':
printFlag = TRUE;
break;
case 'g':
break;
default:
usage(sed_usage);
}
}
}
cp = pos;
/* fprintf(stderr, "replace '%s' with '%s'\n", needle, newNeedle); */
break;
case 'a': /* APPEND */
if (strlen(cp) < 2)
break;
sed_f = f_append;
appendline = ++cp;
/* fprintf(stderr, "append '%s'\n", appendline); */
break;
}
stopNow = TRUE;
break;
default:
usage(sed_usage);
}
}
}
if (argc == 0) {
switch (sed_f) {
case f_none:
break;
case f_replace:
do_sed_repl(stdin, needle, newNeedle, ignoreCase, printFlag,
quietFlag);
break;
case f_append:
do_sed_append(stdin, appendline, quietFlag);
break;
}
} else {
while (argc-- > 0) {
name = *argv++;
fp = fopen(name, "r");
if (fp == NULL) {
perror(name);
continue;
}
switch (sed_f) {
case f_none:
break;
case f_replace:
do_sed_repl(fp, needle, newNeedle, ignoreCase, printFlag,
quietFlag);
break;
case f_append:
do_sed_append(fp, appendline, quietFlag);
break;
}
if (ferror(fp))
perror(name);
fclose(fp);
}
}
exit(TRUE);
}
/* END CODE */