[PATCH] rename: add --dry-run option

* [PATCH] rename: add --dry-run option
@ 2017-02-13 14:08 Alexander F Rødseth
  2017-02-15 12:48 ` Karel Zak
  0 siblings, 1 reply; 3+ messages in thread
From: Alexander F Rødseth @ 2017-02-13 14:08 UTC (permalink / raw)
  To: util-linux

[-- Attachment #1: Type: text/plain, Size: 246 bytes --]

Added a --dry-run and -d option for not making changes when running
the rename command. Also made changes to the man page.

Having a dry-run option is useful when running a scary rename.

-- 
Sincerely,
    Alexander F Rødseth / xyproto

[-- Attachment #2: 0001-rename-add-dry-run-option.patch --]
[-- Type: text/x-patch, Size: 5411 bytes --]

From d75d6b1ce3819bdd99e2d84a79f7d642f021cd55 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexander=20F=20R=C3=B8dseth?= <xyproto@archlinux.org>
Date: Mon, 13 Feb 2017 13:44:38 +0100
Subject: [PATCH] rename: add --dry-run option
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Alexander F Rødseth <xyproto@archlinux.org>
---
 misc-utils/rename.1 | 13 ++++++++-----
 misc-utils/rename.c | 28 +++++++++++++++++-----------
 2 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/misc-utils/rename.1 b/misc-utils/rename.1
index 165d61eff..4023fd5f9 100644
--- a/misc-utils/rename.1
+++ b/misc-utils/rename.1
@@ -22,6 +22,9 @@ Do not rename a symlink but its target.
 .BR \-v , " \-\-verbose"
 Show which files where renamed, if any.
 .TP
+.BR \-d , " \-\-dry-run"
+Do not make any changes.
+.TP
 .BR \-V , " \-\-version"
 Display version information and exit.
 .TP
@@ -60,11 +63,11 @@ rename '_with_long_name' '' file_with_long_name.*
 .RE
 will remove the substring in the filenames.
 .SH WARNING
-The renaming has no safeguards.  If the user has permission to rewrite file names,
-the command will perform the action without any questions.  For example, the
-result can be quite drastic when the command is run as root in the /lib
-directory.  Always make a backup before running the command, unless you truly
-know what you are doing.
+The renaming has no safeguards except the dry-run option.  If the user has
+permission to rewrite file names, the command will perform the action without
+any questions.  For example, the result can be quite drastic when the command
+is run as root in the /lib directory.  Always make a backup before running the
+command, unless you truly know what you are doing.
 .SH "EXIT STATUS"
 .RS
 .PD 0
diff --git a/misc-utils/rename.c b/misc-utils/rename.c
index f53b236e2..d04a9a284 100644
--- a/misc-utils/rename.c
+++ b/misc-utils/rename.c
@@ -53,7 +53,7 @@ static int string_replace(char *from, char *to, char *s, char *orig, char **newn
 	return 0;
 }
 
-static int do_symlink(char *from, char *to, char *s, int verbose)
+static int do_symlink(char *from, char *to, char *s, int verbose, int dry_run)
 {
 	char *newname = NULL, *target = NULL;
 	int ret = 1;
@@ -76,21 +76,21 @@ static int do_symlink(char *from, char *to, char *s, int verbose)
 	target[sb.st_size] = '\0';
 	if (string_replace(from, to, target, target, &newname))
 		ret = 0;
-	else if (0 > unlink(s)) {
+	else if (!dry_run && 0 > unlink(s)) {
 		warn(_("%s: unlink failed"), s);
 		ret = 2;
-	} else if (symlink(newname, s) != 0) {
+	} else if (!dry_run && symlink(newname, s) != 0) {
 		warn(_("%s: symlinking to %s failed"), s, newname);
 		ret = 2;
 	}
-	if (verbose && ret == 1)
+	if (verbose && (dry_run || ret == 1))
 		printf("%s: `%s' -> `%s'\n", s, target, newname);
 	free(newname);
 	free(target);
 	return ret;
 }
 
-static int do_file(char *from, char *to, char *s, int verbose)
+static int do_file(char *from, char *to, char *s, int verbose, int dry_run)
 {
 	char *newname = NULL, *file=NULL;
 	int ret = 1;
@@ -101,11 +101,11 @@ static int do_file(char *from, char *to, char *s, int verbose)
 		file = s;
 	if (string_replace(from, to, file, s, &newname))
 		return 0;
-	else if (rename(s, newname) != 0) {
+	else if (!dry_run && rename(s, newname) != 0) {
 		warn(_("%s: rename to %s failed"), s, newname);
 		ret = 2;
 	}
-	if (verbose && ret == 1)
+	if (verbose && (dry_run || ret == 1))
 		printf("`%s' -> `%s'\n", s, newname);
 	free(newname);
 	return ret;
@@ -124,6 +124,7 @@ static void __attribute__ ((__noreturn__)) usage(FILE * out)
 	fputs(USAGE_OPTIONS, out);
 	fputs(_(" -v, --verbose    explain what is being done\n"), out);
 	fputs(_(" -s, --symlink    act on the target of symlinks\n"), out);
+	fputs(_(" -d, --dry-run    do not make any changes\n"), out);
 	fputs(USAGE_SEPARATOR, out);
 	fputs(USAGE_HELP, out);
 	fputs(USAGE_VERSION, out);
@@ -134,13 +135,14 @@ static void __attribute__ ((__noreturn__)) usage(FILE * out)
 int main(int argc, char **argv)
 {
 	char *from, *to;
-	int i, c, ret = 0, verbose = 0;
-	int (*do_rename)(char *from, char *to, char *s, int verbose) = do_file;
+	int i, c, ret = 0, verbose = 0, dry_run = 0;
+	int (*do_rename)(char *from, char *to, char *s, int verbose, int dry_run) = do_file;
 
 	static const struct option longopts[] = {
 		{"verbose", no_argument, NULL, 'v'},
 		{"version", no_argument, NULL, 'V'},
 		{"help", no_argument, NULL, 'h'},
+		{"dry-run", no_argument, NULL, 'd'},
 		{"symlink", no_argument, NULL, 's'},
 		{NULL, 0, NULL, 0}
 	};
@@ -150,11 +152,14 @@ int main(int argc, char **argv)
 	textdomain(PACKAGE);
 	atexit(close_stdout);
 
-	while ((c = getopt_long(argc, argv, "vsVh", longopts, NULL)) != -1)
+	while ((c = getopt_long(argc, argv, "vsVhd", longopts, NULL)) != -1)
 		switch (c) {
 		case 'v':
 			verbose = 1;
 			break;
+		case 'd':
+			dry_run = 1;
+			break;
 		case 's':
 			do_rename = do_symlink;
 			break;
@@ -163,6 +168,7 @@ int main(int argc, char **argv)
 			return EXIT_SUCCESS;
 		case 'h':
 			usage(stdout);
+			// fallthrough
 		default:
 			errtryhelp(EXIT_FAILURE);
 		}
@@ -179,7 +185,7 @@ int main(int argc, char **argv)
 	to = argv[1];
 
 	for (i = 2; i < argc; i++)
-		ret |= do_rename(from, to, argv[i], verbose);
+		ret |= do_rename(from, to, argv[i], verbose, dry_run);
 
 	switch (ret) {
 	case 0:
-- 
2.11.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread