sbase/grep.c
2014-11-16 12:39:15 +00:00

172 lines
3.1 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 int grep(FILE *, const char *);
static int eflag = 0;
static int vflag = 0;
static int Hflag = 0;
static int many;
static char mode = 0;
struct pattern {
char *pattern;
regex_t preg;
TAILQ_ENTRY(pattern) entry;
};
static TAILQ_HEAD(phead, pattern) phead;
static void
usage(void)
{
enprintf(Error, "usage: %s [-EHcilnqv] [-e pattern] pattern [files...]\n", argv0);
}
int
main(int argc, char *argv[])
{
struct pattern *pnode, *tmp;
int i, n, m, flags = REG_NOSUB, match = NoMatch;
char buf[BUFSIZ];
FILE *fp;
TAILQ_INIT(&phead);
ARGBEGIN {
case 'E':
flags |= REG_EXTENDED;
break;
case 'H':
Hflag = 1;
break;
case 'e':
addpattern(EARGF(usage()));
eflag = 1;
break;
case 'c':
case 'l':
case 'n':
case 'q':
mode = ARGC();
break;
case 'i':
flags |= REG_ICASE;
break;
case 'v':
vflag = 1;
break;
default:
usage();
} ARGEND;
if (argc == 0 && !eflag)
usage(); /* no pattern */
/* If -e is not specified treat it as if it were */
if (!eflag) {
addpattern(argv[0]);
argc--;
argv++;
}
/* Compile regex for all search patterns */
TAILQ_FOREACH(pnode, &phead, entry) {
if ((n = regcomp(&pnode->preg, pnode->pattern, flags)) != 0) {
regerror(n, &pnode->preg, buf, sizeof buf);
enprintf(Error, "invalid pattern: %s\n", buf);
}
}
many = (argc > 1);
if (argc == 0) {
match = grep(stdin, "<stdin>");
} else {
for (i = 0; i < argc; i++) {
if (!(fp = fopen(argv[i], "r"))) {
weprintf("fopen %s:", argv[i]);
match = Error;
continue;
}
m = grep(fp, argv[i]);
if (m == Error || (match != Error && m == Match))
match = m;
fclose(fp);
}
}
TAILQ_FOREACH_SAFE(pnode, &phead, entry, tmp) {
TAILQ_REMOVE(&phead, pnode, entry);
regfree(&pnode->preg);
free(pnode->pattern);
free(pnode);
}
return match;
}
static void
addpattern(const char *pattern)
{
struct pattern *pnode;
pnode = emalloc(sizeof(*pnode));
pnode->pattern = estrdup(pattern);
TAILQ_INSERT_TAIL(&phead, pnode, entry);
}
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 = agetline(&buf, &size, fp)) != -1; n++) {
/* Remove the trailing newline if one is present. */
if (len && buf[len - 1] == '\n')
buf[len - 1] = '\0';
TAILQ_FOREACH(pnode, &phead, entry) {
if (regexec(&pnode->preg, buf, 0, NULL, 0) ^ vflag)
continue;
switch (mode) {
case 'c':
c++;
break;
case 'l':
puts(str);
goto end;
case 'q':
exit(Match);
default:
if (many || Hflag)
printf("%s:", str);
if (mode == 'n')
printf("%ld:", n);
puts(buf);
break;
}
match = Match;
}
}
if (mode == 'c')
printf("%ld\n", c);
end:
if (ferror(fp)) {
weprintf("%s: read error:", str);
match = Error;
}
free(buf);
return match;
}