[thirdparty/util-linux.git] / misc-utils / exch.c

/*
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * 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.
 *
 * Copyright (C) 2023 Red Hat, Inc. All rights reserved.
 * Written by Masatake YAMATO <yamato@redhat.com>
 *
 * exch(1) - a command line interface for RENAME_EXCHANGE of renameat2(2).
 */
#include "c.h"
#include "nls.h"

#include <fcntl.h>
#include <getopt.h>

#ifndef HAVE_RENAMEAT2
# include <sys/syscall.h>
# include <unistd.h>
#endif

#ifndef RENAME_EXCHANGE
# define RENAME_EXCHANGE (1 << 1)
#endif

#if !defined(HAVE_RENAMEAT2) && defined(SYS_renameat2)
static inline int renameat2(int olddirfd, const char *oldpath,
			    int newdirfd, const char *newpath, unsigned int flags)
{
	return syscall (SYS_renameat2, olddirfd, oldpath, newdirfd, newpath, flags);
}
#endif

static void __attribute__((__noreturn__)) usage(void)
{
	FILE *out = stdout;

	fputs(USAGE_HEADER, out);
	fprintf(out, _(" %s [options] oldpath newpath\n"), program_invocation_short_name);
	fputs(USAGE_SEPARATOR, out);
	fputs(_("Atomically exchanges paths between two files.\n"), out);

	fputs(USAGE_OPTIONS, out);
	fprintf(out, USAGE_HELP_OPTIONS(30));

	fprintf(out, USAGE_MAN_TAIL("exch(1)"));

	exit(EXIT_SUCCESS);
}

int main(int argc, char **argv)
{
	int c;
	int rc;

	static const struct option longopts[] = {
		{ "version",    no_argument, NULL, 'V' },
		{ "help",	no_argument, NULL, 'h' },
		{ NULL }
	};

	setlocale(LC_ALL, "");
	bindtextdomain(PACKAGE, LOCALEDIR);
	textdomain(PACKAGE);

	while ((c = getopt_long(argc, argv, "Vh", longopts, NULL)) != -1) {
		switch (c) {
		case 'V':
			print_version(EXIT_SUCCESS);
		case 'h':
			usage();
		default:
			errtryhelp(EXIT_FAILURE);
		}
	}

	if (argc - optind < 2) {
		warnx(_("too few arguments"));
		errtryhelp(EXIT_FAILURE);
	} else if (argc - optind > 2) {
		warnx(_("too many arguments"));
		errtryhelp(EXIT_FAILURE);
	}

	rc = renameat2(AT_FDCWD, argv[optind],
		       AT_FDCWD, argv[optind + 1], RENAME_EXCHANGE);
	if (rc)
		warn(_("failed to exchange \"%s\" and \"%s\""),
		     argv[optind], argv[optind + 1]);

	return rc == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
}
Commit	Line	Data
cd094a05	1	/*
8380ce72	2	* SPDX-License-Identifier: GPL-2.0-or-later
cd094a05 MY	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
8380ce72 KZ	9	* Copyright (C) 2023 Red Hat, Inc. All rights reserved.
8380ce72 KZ	10	* Written by Masatake YAMATO <yamato@redhat.com>
cd094a05	11	*
8380ce72	12	* exch(1) - a command line interface for RENAME_EXCHANGE of renameat2(2).
cd094a05	13	*/
cd094a05 MY	14	#include "c.h"
	15	#include "nls.h"
	16
	17	#include <fcntl.h>
	18	#include <getopt.h>
	19
	20	#ifndef HAVE_RENAMEAT2
8380ce72 KZ	21	# include <sys/syscall.h>
	22	# include <unistd.h>
	23	#endif
cd094a05 MY	24
cd094a05 MY	25	#ifndef RENAME_EXCHANGE
8380ce72	26	# define RENAME_EXCHANGE (1 << 1)
cd094a05 MY	27	#endif
cd094a05 MY	28
8a7c8803	29	#if !defined(HAVE_RENAMEAT2) && defined(SYS_renameat2)
cd094a05 MY	30	static inline int renameat2(int olddirfd, const char *oldpath,
	31	int newdirfd, const char *newpath, unsigned int flags)
	32	{
	33	return syscall (SYS_renameat2, olddirfd, oldpath, newdirfd, newpath, flags);
	34	}
cd094a05 MY	35	#endif
	36
	37	static void __attribute__((__noreturn__)) usage(void)
	38	{
	39	FILE *out = stdout;
	40
	41	fputs(USAGE_HEADER, out);
	42	fprintf(out, _(" %s [options] oldpath newpath\n"), program_invocation_short_name);
8380ce72 KZ	43	fputs(USAGE_SEPARATOR, out);
8380ce72 KZ	44	fputs(_("Atomically exchanges paths between two files.\n"), out);
cd094a05 MY	45
	46	fputs(USAGE_OPTIONS, out);
	47	fprintf(out, USAGE_HELP_OPTIONS(30));
	48
	49	fprintf(out, USAGE_MAN_TAIL("exch(1)"));
	50
	51	exit(EXIT_SUCCESS);
	52	}
	53
	54	int main(int argc, char **argv)
	55	{
	56	int c;
	57	int rc;
	58
	59	static const struct option longopts[] = {
	60	{ "version", no_argument, NULL, 'V' },
	61	{ "help", no_argument, NULL, 'h' },
75f4d809	62	{ NULL }
cd094a05 MY	63	};
	64
	65	setlocale(LC_ALL, "");
	66	bindtextdomain(PACKAGE, LOCALEDIR);
	67	textdomain(PACKAGE);
	68
	69	while ((c = getopt_long(argc, argv, "Vh", longopts, NULL)) != -1) {
	70	switch (c) {
	71	case 'V':
	72	print_version(EXIT_SUCCESS);
	73	case 'h':
	74	usage();
	75	default:
	76	errtryhelp(EXIT_FAILURE);
	77	}
	78	}
	79
	80	if (argc - optind < 2) {
	81	warnx(_("too few arguments"));
	82	errtryhelp(EXIT_FAILURE);
	83	} else if (argc - optind > 2) {
	84	warnx(_("too many arguments"));
	85	errtryhelp(EXIT_FAILURE);
	86	}
	87
	88	rc = renameat2(AT_FDCWD, argv[optind],
	89	AT_FDCWD, argv[optind + 1], RENAME_EXCHANGE);
	90	if (rc)
	91	warn(_("failed to exchange \"%s\" and \"%s\""),
	92	argv[optind], argv[optind + 1]);
	93
	94	return rc == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
	95	}