micro-utils/src/grep.c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <regex.h>

typedef struct {
	char *pattern;
	regex_t rgex;
} PATTERN;
static PATTERN *regexs;
static size_t r_size;

static int addpattern(char *str) {
	if (regexs == NULL) {
		regexs = malloc(sizeof(PATTERN));
		if (regexs == NULL) {
			fprintf(stderr, "grep: malloc failed\n");
			return 1;
		}
	}

	PATTERN *regexs_tmp = realloc(regexs, (r_size + 1) * sizeof(PATTERN));
	if (regexs_tmp == NULL) {
		free(regexs);

		fprintf(stderr, "grep: realloc failed\n");
		return 1;
	}
	regexs = regexs_tmp;

	regexs[r_size].pattern = str;

	r_size++;
	return 0;
}

int main(int argc, char **argv) {

	int opt;
	while ((opt = getopt(argc, argv, "e:")) != -1) {
		switch (opt) {
			case 'e':
				if (addpattern(optarg))
					return 1;

				break;

			default:
				printf("grep [e] [FILE]\n\t-e PTRN Pattern to match\n");
				return 0;
		}
	}

	argv += optind;
	argc -= optind;
	if (r_size == 0) {
		fprintf(stderr, "grep: no patterns specified\n");
		return 1;
	}

	free(regexs);
	return 0;
}