micro-utils/src/coreutils/nl/nl.c

#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "config.h"

int w_flag = 4;
int lines = 1;

int nl(const char *path) {
	FILE *fp = stdin;

	if (strcmp(path, "-"))
		fp = fopen(path, "r");

	if (fp == NULL) {
		fprintf(stderr, "nl: %s: %s\n", path, strerror(errno));
		return 1;
	}

	char *buf = NULL;
	size_t size = 0;
	while (getline(&buf, &size, fp) != EOF) {
		if (strlen(buf) > 1)
			fprintf(stdout, "%*d\t%s", w_flag, lines++, buf);

		else
			fprintf(stdout, "%*s\t%s", w_flag, " ", buf);
	}

	if (buf != NULL)
		free(buf);

	if (strcmp(path, "-"))
		fclose(fp);

	return 0;
}

int main(int argc, char **argv) {
	int opt;
	while ((opt = getopt(argc, argv, "w:v:")) != -1) {
		switch (opt) {
			case 'w':
				w_flag = atoi(optarg);
				break;

			case 'v':
				lines = atoi(optarg);
				break;

			default:
				printf("nl [wv] [file1 file2...]\n\t-w N Width of line numbers\n\t-v N Start from N\n");
				return 0;
		}
	}

	argv += optind;
	argc -= optind;

	if (argc == 0)
		return nl("-");

	else {
		int ret = 0;
		for (int i = 0; i < argc; i++)
			if (nl(argv[i]))
				ret = 1;

		return ret;
	}
}