sbase/grep.c
sin 8767e4b320 Properly handle multiline patterns in grep(1)
We should be POSIX compliant now.
2014-11-20 19:56:44 +00:00

253 lines
4.6 KiB
C

/* See LICENSE file for copyright and license details. */
#include <regex.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "queue.h"
#include "text.h"
#include "util.h"
enum { Match = 0, NoMatch = 1, Error = 2 };
static void addpattern(const char *);
static void addpatternfile(FILE *);
static int grep(FILE *, const char *);
static int Fflag;
static int Hflag;
static int eflag;
static int fflag;
static int hflag;
static int iflag;
static int sflag;
static int vflag;
static int xflag;
static int many;
static int mode;
struct pattern {
char *pattern;
regex_t preg;
SLIST_ENTRY(pattern) entry;
};
static SLIST_HEAD(phead, pattern) phead;
static void
usage(void)
{
enprintf(Error, "usage: %s [-EFHcilnqsvx] [-e pattern] [-f file] pattern [files...]\n", argv0);
}
int
main(int argc, char *argv[])
{
struct pattern *pnode;
int i, m, flags = REG_NOSUB, match = NoMatch;
FILE *fp;
char *arg;
SLIST_INIT(&phead);
ARGBEGIN {
case 'E':
flags |= REG_EXTENDED;
break;
case 'F':
Fflag = 1;
break;
case 'H':
Hflag = 1;
break;
case 'e':
arg = EARGF(usage());
fp = fmemopen(arg, strlen(arg) + 1, "r");
addpatternfile(fp);
fclose(fp);
eflag = 1;
break;
case 'f':
arg = EARGF(usage());
fp = fopen(arg, "r");
if (!fp)
enprintf(Error, "fopen %s:", arg);
addpatternfile(fp);
fclose(fp);
fflag = 1;
break;
case 'h':
hflag = 1;
break;
case 'c':
case 'l':
case 'n':
case 'q':
mode = ARGC();
break;
case 'i':
flags |= REG_ICASE;
iflag = 1;
break;
case 's':
sflag = 1;
break;
case 'v':
vflag = 1;
break;
case 'x':
xflag = 1;
break;
default:
usage();
} ARGEND;
if (argc == 0 && !eflag && !fflag)
usage(); /* no pattern */
/* just add literal pattern to list */
if (!eflag && !fflag) {
fp = fmemopen(argv[0], strlen(argv[0]) + 1, "r");
addpatternfile(fp);
fclose(fp);
argc--;
argv++;
}
if (!Fflag)
/* Compile regex for all search patterns */
SLIST_FOREACH(pnode, &phead, entry)
enregcomp(Error, &pnode->preg, pnode->pattern, flags);
many = (argc > 1);
if (argc == 0) {
match = grep(stdin, "<stdin>");
} else {
for (i = 0; i < argc; i++) {
if (!(fp = fopen(argv[i], "r"))) {
if (!sflag)
weprintf("fopen %s:", argv[i]);
match = Error;
continue;
}
m = grep(fp, argv[i]);
if (m == Error || (match != Error && m == Match))
match = m;
fclose(fp);
}
}
while (!SLIST_EMPTY(&phead)) {
pnode = SLIST_FIRST(&phead);
SLIST_REMOVE_HEAD(&phead, entry);
if (!Fflag)
regfree(&pnode->preg);
free(pnode->pattern);
free(pnode);
}
return match;
}
static void
addpattern(const char *pattern)
{
struct pattern *pnode;
char *tmp;
/* a null BRE/ERE matches every line */
if (!Fflag)
if (pattern[0] == '\0')
pattern = ".";
if (!Fflag && xflag) {
tmp = emalloc(strlen(pattern) + 3);
snprintf(tmp, strlen(pattern) + 3, "%s%s%s",
pattern[0] == '^' ? "" : "^",
pattern,
pattern[strlen(pattern) - 1] == '$' ? "" : "$");
} else {
tmp = estrdup(pattern);
}
pnode = emalloc(sizeof(*pnode));
pnode->pattern = tmp;
SLIST_INSERT_HEAD(&phead, pnode, entry);
}
static void
addpatternfile(FILE *fp)
{
char *buf = NULL;
size_t len = 0, size = 0;
while ((len = getline(&buf, &size, fp)) != -1) {
if (len && buf[len - 1] == '\n')
buf[len - 1] = '\0';
addpattern(buf);
}
free(buf);
}
static int
grep(FILE *fp, const char *str)
{
char *buf = NULL;
size_t len = 0, size = 0;
long c = 0, n;
struct pattern *pnode;
int match = NoMatch;
for (n = 1; (len = getline(&buf, &size, fp)) != -1; n++) {
/* Remove the trailing newline if one is present. */
if (len && buf[len - 1] == '\n')
buf[len - 1] = '\0';
SLIST_FOREACH(pnode, &phead, entry) {
if (!Fflag) {
if (regexec(&pnode->preg, buf[0] == '\0' ? "\n" : buf, 0, NULL, 0) ^ vflag)
continue;
} else {
if (!xflag) {
if ((iflag ? strcasestr : strstr)(buf, pnode->pattern))
match = Match;
else
match = NoMatch;
} else {
if (!(iflag ? strcasecmp : strcmp)(buf, pnode->pattern))
match = Match;
else
match = NoMatch;
}
if (match ^ vflag)
continue;
}
switch (mode) {
case 'c':
c++;
break;
case 'l':
puts(str);
goto end;
case 'q':
exit(Match);
default:
if (!hflag && (many || Hflag))
printf("%s:", str);
if (mode == 'n')
printf("%ld:", n);
puts(buf);
break;
}
match = Match;
break;
}
}
if (mode == 'c')
printf("%ld\n", c);
end:
if (ferror(fp)) {
weprintf("%s: read error:", str);
match = Error;
}
free(buf);
return match;
}