exch: cosmetic changes

* use the same license header as in other utuls
* make sure SYS_renamea2 defined
* small change to usage()

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/misc-utils/exch.1.adoc b/misc-utils/exch.1.adoc
index fef78e8c08f532bdb98ac87e966025631cc07fa9..b1c51d41ba45c36169b56875bcb1853d107191b9 100644 (file)
--- a/misc-utils/exch.1.adoc
+++ b/misc-utils/exch.1.adoc
@@ -8,7 +8,7 @@
 
 == NAME
 
-exch - a command line interface for RENAME_EXCHANGE of renameat2(2)
+exch - atomically exchanges paths between two files
 
 == SYNOPSIS
 

diff --git a/misc-utils/exch.c b/misc-utils/exch.c
index 0181bd9e6c953147e778088ae8d33ef064049afd..3a8e240edaf73261ed9d52fd24e6663001f7a902 100644 (file)
--- a/misc-utils/exch.c
+++ b/misc-utils/exch.c
@@ -1,24 +1,16 @@
 /*
- * exch(1) - a command line interface for RENAME_EXCHANGE of renameat2(2).
- *
- * Copyright (C) 2023 Red Hat, Inc. All rights reserved.
- * Written by Masatake YAMATO <yamato@redhat.com>
+ * 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.
  *
- * 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.
+ * Copyright (C) 2023 Red Hat, Inc. All rights reserved.
+ * Written by Masatake YAMATO <yamato@redhat.com>
  *
- * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ * exch(1) - a command line interface for RENAME_EXCHANGE of renameat2(2).
  */
-
 #include "c.h"
 #include "nls.h"
 
@@ -26,20 +18,20 @@
 #include <getopt.h>
 
 #ifndef HAVE_RENAMEAT2
-
-#include <sys/syscall.h>
-#include <unistd.h>
+# include <sys/syscall.h>
+# include <unistd.h>
+#endif
 
 #ifndef RENAME_EXCHANGE
-#define RENAME_EXCHANGE (1 << 1)
+# define RENAME_EXCHANGE (1 << 1)
 #endif
 
+#if !defined(HAVE_RENAMEAT2) && defined(SYS_renamea2)
 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)
@@ -48,6 +40,8 @@ static void __attribute__((__noreturn__)) usage(void)
 
        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));