sbase/grep.c

100 lines
1.7 KiB
C

/* See LICENSE file for copyright and license details. */
#include <regex.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
static void grep(FILE *, const char *, regex_t *);
static bool iflag = false;
static bool vflag = false;
static bool many;
static bool match = false;
static char mode = 0;
int
main(int argc, char *argv[])
{
char c;
int flags = 0;
regex_t preg;
FILE *fp;
while((c = getopt(argc, argv, "cilnqv")) != -1)
switch(c) {
case 'c':
case 'l':
case 'n':
case 'q':
mode = c;
break;
case 'i':
iflag = true;
break;
case 'v':
vflag = true;
break;
default:
exit(EXIT_FAILURE);
}
if(optind == argc) {
fprintf(stderr, "usage: %s [-cilnqv] pattern [files...]\n", argv[0]);
exit(2);
}
if(mode == 'c')
flags |= REG_NOSUB;
if(iflag)
flags |= REG_ICASE;
regcomp(&preg, argv[optind++], flags);
many = (argc > optind+1);
if(optind == argc)
grep(stdin, "<stdin>", &preg);
else for(; optind < argc; optind++) {
if(!(fp = fopen(argv[optind], "r"))) {
fprintf(stderr, "fopen %s: ", argv[optind]);
perror(NULL);
exit(2);
}
grep(fp, argv[optind], &preg);
fclose(fp);
}
return match ? 0 : 1;
}
void
grep(FILE *fp, const char *str, regex_t *preg)
{
char buf[BUFSIZ];
int n, c = 0;
for(n = 1; fgets(buf, sizeof buf, fp); n++) {
if(regexec(preg, buf, 0, NULL, 0) ^ vflag)
continue;
if(mode == 'c')
c++;
else if(mode == 'l') {
puts(str);
break;
}
else if(mode == 'q')
exit(0);
else {
if(many)
printf("%s:", str);
if(mode == 'n')
printf("%d:", n);
fputs(buf, stdout);
}
match = true;
}
if(mode == 'c')
printf("%d\n", c);
if(ferror(fp)) {
fprintf(stderr, "%s: read error: ", str);
perror(NULL);
exit(2);
}
}