busybox/miscutils/readahead.c

/* vi: set sw=4 ts=4: */
/*
 * readahead implementation for busybox
 *
 * Preloads the given files in RAM, to reduce access time.
 * Does this by calling the readahead(2) system call.
 *
 * Copyright (C) 2006  Michael Opdenacker <michael@free-electrons.com>
 *
 * Licensed under GPLv2 or later, see file License in this tarball for details.
 */

#include "libbb.h"

int readahead_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int readahead_main(int argc, char **argv)
{
	int retval = EXIT_SUCCESS;

	if (argc == 1) bb_show_usage();

	while (*++argv) {
		int fd = open_or_warn(*argv, O_RDONLY);
		if (fd >= 0) {
			off_t len;
			int r;

			/* fdlength was reported to be unreliable - use seek */
			len = xlseek(fd, 0, SEEK_END);
			xlseek(fd, 0, SEEK_SET);
			r = readahead(fd, 0, len);
			close(fd);
			if (r >= 0)
				continue;
		}
		retval = EXIT_FAILURE;
	}

	return retval;
}
1	niro	532	/* vi: set sw=4 ts=4: */
2			/*
3			* readahead implementation for busybox
4			*
5			* Preloads the given files in RAM, to reduce access time.
6			* Does this by calling the readahead(2) system call.
7			*
8			* Copyright (C) 2006 Michael Opdenacker <michael@free-electrons.com>
9			*
10			* Licensed under GPLv2 or later, see file License in this tarball for details.
11			*/
12
13	niro	816	#include "libbb.h"
14	niro	532
15	niro	816	int readahead_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
16	niro	532	int readahead_main(int argc, char **argv)
17			{
18			int retval = EXIT_SUCCESS;
19
20			if (argc == 1) bb_show_usage();
21
22			while (*++argv) {
23	niro	816	int fd = open_or_warn(*argv, O_RDONLY);
24			if (fd >= 0) {
25			off_t len;
26			int r;
27	niro	532
28	niro	816	/* fdlength was reported to be unreliable - use seek */
29			len = xlseek(fd, 0, SEEK_END);
30			xlseek(fd, 0, SEEK_SET);
31			r = readahead(fd, 0, len);
32			close(fd);
33			if (r >= 0)
34			continue;
35	niro	532	}
36			retval = EXIT_FAILURE;
37			}
38
39			return retval;
40			}