utils-std

commit: 25b4d174ea465c365fd5356d7a73ef49fe72dc24
parent 4ad6ddd0e1587ec03e5c11fac8dce09e92ab2b79
Author: Haelwenn (lanodan) Monnier <contact@hacktivis.me>
Date:   Sun,  2 Jun 2024 08:20:53 +0200

cmd/mv: Align overwriting to POSIX

Diffstat:
M
cmd/mv.c
55
+++++++++++++++++++++++++++++++++----------------------
M
test-cmd/mv.t
48
++++++++++++++++++++++++++++++++++++++++++++++--

2 files changed, 79 insertions(+), 24 deletions(-)
diff --git a/cmd/mv.c b/cmd/mv.c
@@ -31,6 +31,8 @@ char *argv0 = "mv";
 
 bool no_clob = false, force = false, interact = false, verbose = false;
 
+static int stdin_tty = 0;
+
 struct named_fd
 {
 	int fd;
@@ -70,20 +72,23 @@ do_renameat(const char *restrict src, struct named_fd destdir, const char *restr
 		return -1;
 	}
 
-	int ret = faccessat(destdir.fd, dest, F_OK, 0);
-	if(ret == 0)
+	errno = 0;
+
+	struct stat dest_status;
+	int ret = fstatat(destdir.fd, dest, &dest_status, 0);
+	if(ret < 0 && errno != ENOENT)
 	{
-		struct stat dest_status;
-		if(fstatat(destdir.fd, dest, &dest_status, 0) < 0)
-		{
-			fprintf(stderr,
-			        "mv: Failed getting status for destination file '%s/%s': %s\n",
-			        destdir.name,
-			        dest,
-			        strerror(errno));
-			return -1;
-		}
+		fprintf(stderr,
+		        "mv: Failed getting status for destination file '%s/%s': %s\n",
+		        destdir.name,
+		        dest,
+		        strerror(errno));
+		return -1;
+	}
+	errno = 0;
 
+	if(ret == 0)
+	{
 		struct stat src_status;
 		if(fstatat(AT_FDCWD, src, &src_status, 0) < 0)
 		{
@@ -109,25 +114,28 @@ do_renameat(const char *restrict src, struct named_fd destdir, const char *restr
 
 		if(!force)
 		{
-			if(interact || isatty(STDIN_FILENO))
+			if(interact)
 			{
-				errno = 0;
 				if(!consentf(
 				       "mv: Destination file '%s/%s' already exists, overwrite? [yN] ", destdir.name, dest))
 					return 0;
 			}
-			else
+			else if(stdin_tty)
 			{
-				errno = 0;
-				fprintf(stderr, "mv: Destination file '%s/%s' already exists.\n", destdir.name, dest);
-				return 0;
+				if(faccessat(destdir.fd, dest, W_OK, 0) == 0)
+				{
+					if(!consentf("mv: No write permissions for destination file '%s/%s', overwrite? [yN] ",
+					             destdir.name,
+					             dest))
+						return 0;
+				}
+				else
+				{
+					errno = 0;
+				}
 			}
 		}
 	}
-	else
-	{
-		errno = 0;
-	}
 
 	assert(errno == 0);
 	if(renameat(AT_FDCWD, src, destdir.fd, dest) < 0)
@@ -257,6 +265,9 @@ main(int argc, char *argv[])
 
 	consent_init();
 
+	stdin_tty = isatty(STDIN_FILENO);
+	if(!stdin_tty) errno = 0;
+
 	if(destdir.fd == AT_FDCWD)
 	{
 		if(argc <= 1)
diff --git a/test-cmd/mv.t b/test-cmd/mv.t
@@ -9,12 +9,12 @@
 POSIX, non-directory target with a trailing slash is an error
   $ touch nondir file
   $ mv file nondir/
-  mv: Failed opening destination directory 'nondir/': Not a directory
+  mv: Failed getting status for destination file './nondir/': Not a directory
   [1]
   $ test -e file
   $ test -e nondir
   $ mv enoent nondir/
-  mv: Failed moving 'enoent' to './nondir/': No such file or directory
+  mv: Failed getting status for destination file './nondir/': Not a directory
   [1]
   $ rm nondir file
 
@@ -81,6 +81,50 @@ POSIX mv(1) step 2, same file
   $ test -e same-s
   $ rm same Same same-s
 
+Where destination is an existing directory
+  $ mkdir destdir
+  $ touch foo
+  $ mv foo destdir
+  mv: Destination file './destdir' already exists.
+  [1]
+  $ test -f foo
+  $ test -d destdir
+  $ test ! -e destdir/foo
+  $ rm -r destdir
+
+  $ mkdir destdir_trail/
+  $ touch foo_trail
+  $ mv foo_trail destdir_trail/
+  mv: Destination file './destdir_trail/' already exists.
+  [1]
+  $ test -f foo_trail
+  $ test -d destdir_trail
+  $ test ! -e destdir_trail/foo_trail
+  $ rm -r destdir_trail
+  $ rm foo_trail
+
+Where destination is an existing file
+  $ touch foo_file destfile
+  $ mv foo_file destfile
+  $ test ! -e foo_file
+  $ test -f destfile
+  $ rm destfile
+
+  $ touch foo_file_i destfile_i
+  $ printf 'y\n' | mv -i foo_file_i destfile_i
+  mv: Destination file './destfile_i' already exists, overwrite? [yN] y
+  $ test ! -e foo_file_i
+  $ test -f destfile_i
+  $ rm destfile_i
+
+  $ touch foo_file_trail destfile_trail
+  $ mv foo_file_trail destfile_trail/
+  mv: Failed getting status for destination file './destfile_trail/': Not a directory
+  [1]
+  $ test -f foo_file_trail
+  $ test -f destfile_trail
+  $ rm foo_file_trail destfile_trail
+
 Verbose (non-standard)
   $ touch foo
   $ mv -v foo bar