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/*
* pipesz(1) - Set or examine pipe buffer sizes.
*
* Copyright (c) 2022 Nathan Sharp
* Written by Nathan Sharp <nwsharp@live.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.
*
* 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 <getopt.h>
#include <sys/ioctl.h> /* FIONREAD */
#include <fcntl.h> /* F_GETPIPE_SZ F_SETPIPE_SZ */
#include "c.h"
#include "nls.h"
#include "closestream.h" /* close_stdout_atexit */
#include "optutils.h" /* err_exclusive_options */
#include "path.h" /* ul_path_read_s32 */
#include "pathnames.h" /* _PATH_PROC_PIPE_MAX_SIZE */
#include "strutils.h" /* strtos32_or_err strtosize_or_err */
static char opt_check = 0; /* --check */
static char opt_get = 0; /* --get */
static char opt_quiet = 0; /* --quiet */
static int opt_size = -1; /* --set <size> */
static char opt_verbose = 0; /* --verbose */
/* fallback file for default size */
#ifndef PIPESZ_DEFAULT_SIZE_FILE
#define PIPESZ_DEFAULT_SIZE_FILE _PATH_PROC_PIPE_MAX_SIZE
#endif
/* convenience macros, since pipesz is by default very lenient */
#define check(FMT...) do { \
if (opt_check) { \
err(EXIT_FAILURE, FMT); \
} else if (!opt_quiet) { \
warn(FMT); \
} \
} while (0)
#define checkx(FMT...) do { \
if (opt_check) { \
errx(EXIT_FAILURE, FMT); \
} else if (!opt_quiet) { \
warnx(FMT); \
} \
} while (0)
static void __attribute__((__noreturn__)) usage(void)
{
fputs(USAGE_HEADER, stdout);
printf(_(" %s [options] [--set <size>] [--] [command]\n"), program_invocation_short_name);
printf(_(" %s [options] --get\n"), program_invocation_short_name);
fputs(USAGE_SEPARATOR, stdout);
/* TRANSLATORS: 'command' refers to a program argument */
puts(_("Set or examine pipe buffer sizes and optionally execute command."));
fputs(USAGE_OPTIONS, stdout);
puts(_(" -g, --get examine pipe buffers"));
/* TRANSLATORS: '%s' refers to a system file */
printf(
_(" -s, --set <size> set pipe buffer sizes\n"
" size defaults to %s\n"),
PIPESZ_DEFAULT_SIZE_FILE);
fputs(USAGE_SEPARATOR, stdout);
puts(_(" -f, --file <path> act on a file"));
puts(_(" -n, --fd <num> act on a file descriptor"));
puts(_(" -i, --stdin act on standard input"));
puts(_(" -o, --stdout act on standard output"));
puts(_(" -e, --stderr act on standard error"));
fputs(USAGE_SEPARATOR, stdout);
puts(_(" -c, --check do not continue after an error"));
puts(_(" -q, --quiet do not warn of non-fatal errors"));
puts(_(" -v, --verbose provide detailed output"));
fputs(USAGE_SEPARATOR, stdout);
printf(USAGE_HELP_OPTIONS(20));
printf(USAGE_MAN_TAIL("pipesz(1)"));
exit(EXIT_SUCCESS);
}
/*
* performs F_GETPIPE_SZ and FIONREAD
* outputs a table row
*/
static void do_get(int fd, const char *name)
{
int sz, used;
sz = fcntl(fd, F_GETPIPE_SZ);
if (sz < 0) {
/* TRANSLATORS: '%s' refers to a file */
check(_("cannot get pipe buffer size of %s"), name);
return;
}
if (ioctl(fd, FIONREAD, &used))
used = 0;
printf("%s\t%d\t%d\n", name, sz, used);
}
/*
* performs F_SETPIPE_SZ
*/
static void do_set(int fd, const char *name)
{
int sz;
sz = fcntl(fd, F_SETPIPE_SZ, opt_size);
if (sz < 0)
/* TRANSLATORS: '%s' refers to a file */
check(_("cannot set pipe buffer size of %s"), name);
else if (opt_verbose)
/* TRANSLATORS: '%s' refers to a file, '%d' to a buffer size in bytes */
warnx(_("%s pipe buffer size set to %d"), name, sz);
}
/*
* does the requested operation on an fd
*/
static void do_fd(int fd)
{
char name[sizeof(stringify(INT_MIN)) + 3];
sprintf(name, "fd %d", fd);
if (opt_get)
do_get(fd, name);
else
do_set(fd, name);
}
/*
* does the requested operation on a file
*/
static void do_file(const char *path)
{
int fd;
fd = open(path, O_RDONLY | O_CLOEXEC);
if (fd < 0) {
/* TRANSLATORS: '%s' refers to a file */
check(_("cannot open %s"), path);
return;
}
if (opt_get)
do_get(fd, path);
else
do_set(fd, path);
close(fd);
}
/*
* if necessary, determines a default buffer size and places it in opt_size
* returns FALSE if this could not be done
*/
static char set_size_default(void)
{
if (opt_size >= 0)
return TRUE;
if (ul_path_read_s32(NULL, &opt_size, PIPESZ_DEFAULT_SIZE_FILE)) {
/* TRANSLATORS: '%s' refers to a system file */
check(_("cannot parse %s"), PIPESZ_DEFAULT_SIZE_FILE);
return FALSE;
}
if (opt_size < 0) {
/* TRANSLATORS: '%s' refers to a system file */
checkx(_("cannot parse %s"), PIPESZ_DEFAULT_SIZE_FILE);
return FALSE;
}
return TRUE;
}
int main(int argc, char **argv)
{
static const char shortopts[] = "+cef:ghin:oqs:vV";
static const struct option longopts[] = {
{ "check", no_argument, NULL, 'c' },
{ "fd", required_argument, NULL, 'n' },
{ "file", required_argument, NULL, 'f' },
{ "get", no_argument, NULL, 'g' },
{ "help", no_argument, NULL, 'h' },
{ "quiet", no_argument, NULL, 'q' },
{ "set", required_argument, NULL, 's' },
{ "stdin", no_argument, NULL, 'i' },
{ "stdout", no_argument, NULL, 'o' },
{ "stderr", no_argument, NULL, 'e' },
{ "verbose", no_argument, NULL, 'v' },
{ "version", no_argument, NULL, 'V' },
{ NULL, 0, NULL, 0 }
};
static const ul_excl_t excl[] = {
{ 'g', 's' },
{ 0 }
};
int c, fd, n_opt_pipe = 0, n_opt_size = 0;
uintmax_t sz;
int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
close_stdout_atexit();
/* check for --help or --version */
while ((c = getopt_long(argc, argv, shortopts, longopts, NULL)) != -1) {
switch (c) {
case 'h':
usage();
case 'V':
print_version(EXIT_SUCCESS);
}
}
/* gather normal options */
optind = 1;
while ((c = getopt_long(argc, argv, shortopts, longopts, NULL)) != -1) {
err_exclusive_options(c, longopts, excl, excl_st);
switch (c) {
case 'c':
opt_check = TRUE;
break;
case 'e':
++n_opt_pipe;
break;
case 'f':
++n_opt_pipe;
break;
case 'g':
opt_get = TRUE;
break;
case 'i':
++n_opt_pipe;
break;
case 'n':
fd = strtos32_or_err(optarg, _("invalid fd argument"));
++n_opt_pipe;
break;
case 'o':
++n_opt_pipe;
break;
case 'q':
opt_quiet = TRUE;
break;
case 's':
sz = strtosize_or_err(optarg, _("invalid size argument"));
opt_size = sz >= INT_MAX ? INT_MAX : (int)sz;
++n_opt_size;
break;
case 'v':
opt_verbose = TRUE;
break;
default:
errtryhelp(EXIT_FAILURE);
}
}
/* check arguments */
if (opt_get) {
if (argv[optind])
errx(EXIT_FAILURE, _("cannot specify a command with --get"));
/* print column headers, if requested */
if (opt_verbose)
printf("%s\t%s\t%s\n",
/* TRANSLATORS: a column that contains the names of files that are unix pipes */
_("pipe"),
/* TRANSLATORS: a column that contains buffer sizes in bytes */
_("size"),
/* TRANSLATORS: a column that contains an amount of data which has not been used by a program */
_("unread")
);
/* special behavior for --get */
if (!n_opt_pipe) {
do_fd(STDIN_FILENO);
return EXIT_SUCCESS;
}
} else {
if (!set_size_default())
goto execute_command;
if (!opt_quiet && n_opt_size > 1)
warnx(_("using last specified size"));
/* special behavior for --set */
if (!n_opt_pipe) {
do_fd(STDOUT_FILENO);
goto execute_command;
}
}
/* go through the arguments again and do the requested operations */
optind = 1;
while ((c = getopt_long(argc, argv, shortopts, longopts, NULL)) != -1)
switch (c) {
case 'e':
do_fd(STDERR_FILENO);
break;
case 'f':
do_file(optarg);
break;
case 'i':
do_fd(STDIN_FILENO);
break;
case 'n':
/* optarg was checked before, but it's best to be safe */
fd = strtos32_or_err(optarg, _("invalid fd argument"));
do_fd(fd);
break;
case 'o':
do_fd(STDOUT_FILENO);
break;
}
execute_command:
/* exec the command, if it's present */
if (!argv[optind])
return EXIT_SUCCESS;
execvp(argv[optind], &argv[optind]);
errexec(argv[optind]);
}