busybox/miscutils/readahead.c
Pere Orga 5bc8c005a8 move remaining help text from include/usage.src.h
Signed-off-by: Pere Orga <gotrunks@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2011-04-11 03:29:49 +02:00

48 lines
1.0 KiB
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 source tree.
*/
//usage:#define readahead_trivial_usage
//usage: "[FILE]..."
//usage:#define readahead_full_usage "\n\n"
//usage: "Preload FILEs to RAM"
#include "libbb.h"
int readahead_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int readahead_main(int argc UNUSED_PARAM, char **argv)
{
int retval = EXIT_SUCCESS;
if (!argv[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;
}