githubmirror/libuser

samples/field.c
74 строки2 KB
Miloslav Trmač
Update FSF address
06 фев 2012, 19:12
06 фев 2012, 19:1281ae3fa
/*
 * Copyright (C) 2000-2002 Red Hat, Inc.
 *
 * This is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Library General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 */

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

int
main(int argc, char **argv)
{
	int fd;
	struct lu_error *error = NULL;
	gpointer lock;

	if (argc < 4) {
		printf("usage: %s <file> <initial> <field> [value]\n",
		       strchr(argv[0], '/') ?
		       strrchr(argv[0], '/') + 1 : argv[0]);
		exit(1);
	}
	fd = open(argv[1], (argc > 4) ? O_RDWR : O_RDONLY);
	if (fd == -1) {
		fprintf(stderr, "error opening `%s': %s\n", argv[1],
			strerror(errno));
		exit(2);
	}

	if ((lock = lu_util_lock_obtain(fd, &error)) == NULL) {
		fprintf(stderr, "failed to lock `%s': %s\n", argv[1],
			lu_strerror(error));
		close(fd);
		exit(3);
	}

	if (argc > 4) {
		if (!lu_util_field_write(fd, argv[2], atoi(argv[3]),
					 argv[4], &error)) {
			fprintf(stderr, "failed to modify `%s': %s\n",
				argv[1], lu_strerror(error));
		}
	} else {
		char *ret;
		ret = lu_util_field_read(fd, argv[2], atoi(argv[3]), &error);
		if (ret == NULL) {
			fprintf(stderr, "failed to read `%s': %s\n",
				argv[1], lu_strerror(error));
		}
		printf("`%s'\n", ret);
		g_free(ret);
	}
	lu_util_lock_free(lock);
	close(fd);
	return 0;
}