util-linux/misc-utils/fadvise.c
2022-12-28 04:52:15 +00:00

153 lines
3.9 KiB
C

/*
* fadvise - utility to use the posix_fadvise(2)
*
* Copyright (C) 2022 Red Hat, Inc. All rights reserved.
* Written by Masatake YAMATO <yamato@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU 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 would 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 General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <fcntl.h>
#include <getopt.h>
#include <stdbool.h>
#include <stdio.h>
#include "c.h"
#include "nls.h"
#include "strutils.h"
static const struct advice {
const char *name;
int num;
} advices [] = {
{ "normal", POSIX_FADV_NORMAL, },
{ "sequential", POSIX_FADV_SEQUENTIAL, },
{ "random", POSIX_FADV_RANDOM, },
{ "noreuse", POSIX_FADV_NOREUSE, },
{ "willneeded", POSIX_FADV_WILLNEED, },
{ "dontneed", POSIX_FADV_DONTNEED, },
};
static void __attribute__((__noreturn__)) usage(void)
{
FILE *out = stdout;
size_t i;
fputs(USAGE_HEADER, out);
fprintf(out, _(" %s [options] file\n"), program_invocation_short_name);
fprintf(out, _(" %s [options] --fd|-d file-descriptor\n"), program_invocation_short_name);
fputs(USAGE_OPTIONS, out);
fputs(_(" -a, --advice <advice> applying advice to the file (default: \"dontneed\")\n"), out);
fputs(_(" -l, --length <num> length for range operations, in bytes\n"), out);
fputs(_(" -o, --offset <num> offset for range operations, in bytes\n"), out);
fputs(USAGE_SEPARATOR, out);
printf(USAGE_HELP_OPTIONS(23));
fputs(_("\nAvailable values for advice:\n"), out);
for (i = 0; i < ARRAY_SIZE(advices); i++) {
fprintf(out, " %s\n",
advices[i].name);
}
printf(USAGE_MAN_TAIL("fadvise(1)"));
exit(EXIT_SUCCESS);
}
int main(int argc, char ** argv)
{
int c;
int rc;
bool do_close = false;
int fd = -1;
off_t offset = 0;
off_t len = 0;
int advice = POSIX_FADV_DONTNEED;
static const struct option longopts[] = {
{ "advice", required_argument, NULL, 'a' },
{ "fd", required_argument, NULL, 'd' },
{ "length", required_argument, NULL, 'l' },
{ "offset", required_argument, NULL, 'o' },
{ "version", no_argument, NULL, 'V' },
{ "help", no_argument, NULL, 'h' },
{ NULL, 0, NULL, 0 },
};
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
while ((c = getopt_long (argc, argv, "a:d:hl:o:V", longopts, NULL)) != -1) {
switch (c) {
case 'a':
break;
case 'd':
fd = strtos32_or_err(optarg,
_("invalid fd argument"));
break;
case 'l':
len = strtosize_or_err(optarg,
_("invalid length argument"));
break;
case 'o':
offset = strtosize_or_err(optarg,
_("invalid offset argument"));
break;
case 'V':
print_version(EXIT_SUCCESS);
case 'h':
usage();
default:
errtryhelp(EXIT_FAILURE);
}
}
if (optind == argc && fd == -1) {
warnx(_("no file specified"));
errtryhelp(EXIT_FAILURE);
}
if (argc - optind > 0 && fd != -1) {
warnx(_("specify either file descriptor or file name"));
errtryhelp(EXIT_FAILURE);
}
if (argc - optind > 1) {
warnx(_("specify one file descriptor or file name"));
errtryhelp(EXIT_FAILURE);
}
if (fd == -1) {
fd = open(argv[optind], O_RDONLY);
if (fd < 0)
err(EXIT_FAILURE, _("cannot open %s"), argv[optind]);
do_close = true;
}
rc = posix_fadvise(fd,
offset, len,
advice);
if (rc != 0)
warn(_("failed to advise"));
if (do_close)
close(fd);
return rc;
}