[src/trunk]: src/bin/mv New mv -h option.

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f8f47d6e2aeb
branches:  trunk
changeset: 973230:f8f47d6e2aeb
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Wed Jun 24 16:58:12 2020 +0000

description:
New mv -h option.

`mv -h source target' just issues rename(source, target) without
discriminating on whether target resolves to a directory; this way
you can atomically replace a symlink to a directory.

diffstat:

 bin/mv/mv.1 |  13 ++++++++++---
 bin/mv/mv.c |  15 +++++++++------
 2 files changed, 19 insertions(+), 9 deletions(-)

diffs (99 lines):

diff -r f04a09da4da1 -r f8f47d6e2aeb bin/mv/mv.1
--- a/bin/mv/mv.1       Wed Jun 24 16:49:30 2020 +0000
+++ b/bin/mv/mv.1       Wed Jun 24 16:58:12 2020 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: mv.1,v 1.30 2017/07/04 06:50:04 wiz Exp $
+.\"    $NetBSD: mv.1,v 1.31 2020/06/24 16:58:12 riastradh Exp $
 .\"
 .\" Copyright (c) 1989, 1990, 1993
 .\"    The Regents of the University of California.  All rights reserved.
@@ -40,7 +40,7 @@
 .Nd move files
 .Sh SYNOPSIS
 .Nm
-.Op Fl fiv
+.Op Fl fhiv
 .Ar source target
 .Nm
 .Op Fl fiv
@@ -54,7 +54,9 @@
 .Ar target
 operand.
 This form is assumed when the last operand does not name an already
-existing directory.
+existing directory or when the
+.Fl h
+flag is specified.
 .Pp
 In its second form,
 .Nm
@@ -72,6 +74,11 @@
 .It Fl f
 Do not prompt for confirmation before overwriting the destination
 path.
+.It Fl h
+Try to rename the source to the target irrespective of whether the
+target may resolve to a directory.
+This option allows atomically replacing a symbolic link to a
+directory.
 .It Fl i
 Causes
 .Nm
diff -r f04a09da4da1 -r f8f47d6e2aeb bin/mv/mv.c
--- a/bin/mv/mv.c       Wed Jun 24 16:49:30 2020 +0000
+++ b/bin/mv/mv.c       Wed Jun 24 16:58:12 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: mv.c,v 1.45 2016/02/28 10:59:29 mrg Exp $ */
+/* $NetBSD: mv.c,v 1.46 2020/06/24 16:58:12 riastradh Exp $ */
 
 /*
  * Copyright (c) 1989, 1993, 1994
@@ -42,7 +42,7 @@
 #if 0
 static char sccsid[] = "@(#)mv.c       8.2 (Berkeley) 4/2/94";
 #else
-__RCSID("$NetBSD: mv.c,v 1.45 2016/02/28 10:59:29 mrg Exp $");
+__RCSID("$NetBSD: mv.c,v 1.46 2020/06/24 16:58:12 riastradh Exp $");
 #endif
 #endif /* not lint */
 
@@ -65,7 +65,7 @@
 
 #include "pathnames.h"
 
-static int fflg, iflg, vflg;
+static int fflg, hflg, iflg, vflg;
 static int stdin_ok;
 static sig_atomic_t pinfo;
 
@@ -93,8 +93,11 @@
        setprogname(argv[0]);
        (void)setlocale(LC_ALL, "");
 
-       while ((ch = getopt(argc, argv, "ifv")) != -1)
+       while ((ch = getopt(argc, argv, "hifv")) != -1)
                switch (ch) {
+               case 'h':
+                       hflg = 1;
+                       break;
                case 'i':
                        fflg = 0;
                        iflg = 1;
@@ -123,7 +126,7 @@
         * If the stat on the target fails or the target isn't a directory,
         * try the move.  More than 2 arguments is an error in this case.
         */
-       if (stat(argv[argc - 1], &sb) || !S_ISDIR(sb.st_mode)) {
+       if (hflg || stat(argv[argc - 1], &sb) || !S_ISDIR(sb.st_mode)) {
                if (argc > 2)
                        usage();
                exit(do_move(argv[0], argv[1]));
@@ -419,7 +422,7 @@
 static void
 usage(void)
 {
-       (void)fprintf(stderr, "usage: %s [-fiv] source target\n"
+       (void)fprintf(stderr, "usage: %s [-fhiv] source target\n"
            "       %s [-fiv] source ... directory\n", getprogname(),
            getprogname());
        exit(1);