rename: use access(3) to check if a file exists

This is more lightweight than calling stat(3).  In same go add a regression
test to ensure changes like this will not break --no-overwrite option.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/misc-utils/rename.c b/misc-utils/rename.c
index 7c3cdf67da6674664f59acabe2b3fd7d055457b7..cbda638e18faa3a999c0dd645b564ecfa5fc9c86 100644 (file)
--- a/misc-utils/rename.c
+++ b/misc-utils/rename.c
@@ -105,7 +105,6 @@ static int do_file(char *from, char *to, char *s, int verbose, int noact, int no
 {
        char *newname = NULL, *file=NULL;
        int ret = 1;
-       struct stat sb;
 
        if (strchr(from, '/') == NULL && strchr(to, '/') == NULL)
                file = strrchr(s, '/');
@@ -113,7 +112,7 @@ static int do_file(char *from, char *to, char *s, int verbose, int noact, int no
                file = s;
        if (string_replace(from, to, file, s, &newname))
                return 0;
-       if (nooverwrite && stat(newname, &sb) == 0) {
+       if (nooverwrite && access(newname, F_OK) == 0) {
                printf(_("Skipping existing file: `%s'\n"), newname);
                ret = 0;
        }

diff --git a/tests/expected/rename/overwrite b/tests/expected/rename/overwrite
new file mode 100644 (file)
index 0000000..b16f799
--- /dev/null
+++ b/tests/expected/rename/overwrite
@@ -0,0 +1 @@
+Skipping existing file: `rename_to'

diff --git a/tests/ts/rename/overwrite b/tests/ts/rename/overwrite
new file mode 100755 (executable)
index 0000000..be5b24d
--- /dev/null
+++ b/tests/ts/rename/overwrite
@@ -0,0 +1,31 @@
+#!/bin/bash
+
+#
+# Copyright (C) 2017 Sami Kerola <kerolasa@iki.fi>
+#
+# This file is part of util-linux.
+#
+# This file 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 file is distributed in the hope that it will 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.
+#
+TS_TOPDIR="${0%/*}/../.."
+TS_DESC="overwrite"
+
+. $TS_TOPDIR/functions.sh
+ts_init "$*"
+
+ts_check_test_command "$TS_CMD_RENAME"
+ts_cd "$TS_OUTDIR"
+
+touch rename_from rename_to
+$TS_CMD_RENAME -v --no-overwrite from to rename_from > $TS_OUTPUT 2>&1
+rm rename_from rename_to >> $TS_OUTPUT 2>&1
+
+ts_finalize