Module Name: src
Committed By: kre
Date: Sat Feb 10 00:19:30 UTC 2024
Modified Files:
src/usr.bin/touch: touch.1 touch.c
Log Message:
Add a -D option to touch, which acts like the -d option added to
chmod/chown/chgrp (probably others) in the not too far distant past,
and causes the operation to be a no-op if no actual change would be
made (avoiding updating the file's ctime for no reason).
That is, with touch, -D causes no modifying sys call to be made to
a file if that file's atime and mtime are already set to the values
that would be used. A common case for this is when a "-r ref-file"
is also a target file for the operation.
Unfortunately -d was already taken in touch, so next best available is -D.
To generate a diff of this commit:
cvs rdiff -u -r1.28 -r1.29 src/usr.bin/touch/touch.1
cvs rdiff -u -r1.39 -r1.40 src/usr.bin/touch/touch.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.bin/touch/touch.1
diff -u src/usr.bin/touch/touch.1:1.28 src/usr.bin/touch/touch.1:1.29
--- src/usr.bin/touch/touch.1:1.28 Fri Feb 9 23:41:48 2024
+++ src/usr.bin/touch/touch.1 Sat Feb 10 00:19:30 2024
@@ -1,4 +1,4 @@
-.\" $NetBSD: touch.1,v 1.28 2024/02/09 23:41:48 kre Exp $
+.\" $NetBSD: touch.1,v 1.29 2024/02/10 00:19:30 kre Exp $
.\"
.\" Copyright (c) 1991, 1993
.\" The Regents of the University of California. All rights reserved.
@@ -32,7 +32,7 @@
.\"
.\" @(#)touch.1 8.3 (Berkeley) 4/28/95
.\"
-.Dd February 9, 2024
+.Dd February 10, 2024
.Dt TOUCH 1
.Os
.Sh NAME
@@ -40,7 +40,7 @@
.Nd change file access and modification times
.Sh SYNOPSIS
.Nm
-.Op Fl acfhm
+.Op Fl acDfhm
.Op Fl d Ar posix-datetime|human-datetime
.Op Fl Fl \|date Ar posix-datetime|human-datetime
.Op Fl R Ar ref-file
@@ -77,6 +77,11 @@ The
.Nm
utility does not treat this as an error.
No error messages are displayed and the exit value is not affected.
+.Pp
+.It Fl D
+Do not attempt to adjust a
+.Ar file Ns 's
+times if they are already set to the values specified.
.Pp
.It Fl d Ar posix-datetime
.It Fl d Ar human-datetime
@@ -360,6 +365,56 @@ of the
.Ar path
file to the current time of day.
.Pp
+.Dl touch -Dh -d human-datetime -t CCYYMMDDhhmm.ss -R file file
+.Pp
+Provided
+.Ar file
+exists, this parses the
+.Ar human-datetime
+and
+.Ar CCYYMMDDhhmm.ss
+arguments,
+verifying that they would be suitable for use with
+.Nm ,
+then does nothing, as the final time specification
+.Pq Fl R
+specifies to take the times from
+.Ar file
+and apply them to
+.Ar file
+itself, changing nothing, which the
+.Fl D
+option then prevents from actually occurring.
+That is, this merely tests that the
+.Ar human-datetime
+and
+.Ar datetime
+argumments to
+.Fl d
+and
+.Fl t
+respectively are valid, and could be used to specify a time.
+Use of both
+.Fl h
+and
+.Fl R
+means this works if
+.Ar file
+is a symbolic link,
+even one which does not reference an existing file,
+as well as if it is some other file type.
+Use of
+.Fl R
+requires that
+.Ar file
+exists,
+though if it does not, and an error is generated for that reason,
+the
+.Fl d
+and
+.Fl t
+arguments would have already been successfully processed.
+.Pp
.Dl touch -m -d '-1 day' somefile
.Pp
Set the modify time for
Index: src/usr.bin/touch/touch.c
diff -u src/usr.bin/touch/touch.c:1.39 src/usr.bin/touch/touch.c:1.40
--- src/usr.bin/touch/touch.c:1.39 Fri Feb 9 23:41:48 2024
+++ src/usr.bin/touch/touch.c Sat Feb 10 00:19:30 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: touch.c,v 1.39 2024/02/09 23:41:48 kre Exp $ */
+/* $NetBSD: touch.c,v 1.40 2024/02/10 00:19:30 kre Exp $ */
/*
* Copyright (c) 1993
@@ -39,7 +39,7 @@ __COPYRIGHT("@(#) Copyright (c) 1993\
#if 0
static char sccsid[] = "@(#)touch.c 8.2 (Berkeley) 4/28/95";
#endif
-__RCSID("$NetBSD: touch.c,v 1.39 2024/02/09 23:41:48 kre Exp $");
+__RCSID("$NetBSD: touch.c,v 1.40 2024/02/10 00:19:30 kre Exp $");
#endif /* not lint */
#include <sys/types.h>
@@ -91,18 +91,18 @@ main(int argc, char *argv[])
{
struct stat sb;
struct timespec ts[2];
- int aflag, cflag, hflag, mflag, ch, fd, len, rval, timeset;
+ int aflag, cflag, Dflag, hflag, mflag, ch, fd, len, rval, timeset;
char *p;
int (*change_file_times)(const char *, const struct timespec *);
int (*get_file_status)(const char *, struct stat *);
setlocale(LC_ALL, "");
- aflag = cflag = hflag = mflag = timeset = 0;
+ aflag = cflag = Dflag = hflag = mflag = timeset = 0;
if (clock_gettime(CLOCK_REALTIME, &ts[0]))
err(1, "clock_gettime");
- while ((ch = getopt_long(argc, argv, "acd:fhmR:r:t:", touch_longopts,
+ while ((ch = getopt_long(argc, argv, "acDd:fhmR:r:t:", touch_longopts,
NULL)) != -1)
switch (ch) {
case 'a':
@@ -111,6 +111,9 @@ main(int argc, char *argv[])
case 'c':
cflag = 1;
break;
+ case 'D':
+ Dflag = 1;
+ break;
case 'd':
timeset = 1;
if (!stime_posix(optarg, ts))
@@ -200,6 +203,11 @@ main(int argc, char *argv[])
if (!mflag)
ts[1] = sb.st_mtimespec;
+ if (Dflag &&
+ timespeccmp(&ts[0], &sb.st_atimespec, ==) &&
+ timespeccmp(&ts[1], &sb.st_mtimespec, ==))
+ continue;
+
/* Try utimes(2). */
if (!(*change_file_times)(*argv, ts))
continue;
@@ -527,7 +535,7 @@ static void
usage(void)
{
(void)fprintf(stderr,
- "Usage: %s [-acfhm] [-d|--date datetime] [-R|-r|--reference file]"
+ "Usage: %s [-acDfhm] [-d|--date datetime] [-R|-r|--reference file]"
" [-t time] file ...\n", getprogname());
exit(EXIT_FAILURE);
}
