From 401c9fda42a465243e0816e882373e14c30c9df1 Mon Sep 17 00:00:00 2001
From: Jaakko Heinonen <jh@FreeBSD.org>
Date: Sat, 4 Feb 2012 13:37:31 +0000
Subject: [PATCH] Remove useless and potentially dangerous rw() function which
 tries to update access and modification times by reading and writing the
 file. chmod(2) in rw() doesn't help because utimes(2) allow owner and the
 super-user to change times. Using just utimes(2) should be sufficient.

The -f option becomes no-op.

Reviewed by:	jilles
---
 usr.bin/touch/touch.1 |  7 ++---
 usr.bin/touch/touch.c | 68 ++++---------------------------------------
 2 files changed, 8 insertions(+), 67 deletions(-)

diff --git a/usr.bin/touch/touch.1 b/usr.bin/touch/touch.1
index 1f3b8c20bc17..c2b0a607fa2d 100644
--- a/usr.bin/touch/touch.1
+++ b/usr.bin/touch/touch.1
@@ -31,7 +31,7 @@
 .\"     @(#)touch.1	8.3 (Berkeley) 4/28/95
 .\" $FreeBSD$
 .\"
-.Dd April 28, 1995
+.Dd February 4, 2012
 .Dt TOUCH 1
 .Os
 .Sh NAME
@@ -40,7 +40,7 @@
 .Sh SYNOPSIS
 .Nm
 .Op Fl A Ar [-][[hh]mm]SS
-.Op Fl acfhm
+.Op Fl achm
 .Op Fl r Ar file
 .Op Fl t Ar [[CC]YY]MMDDhhmm[.SS]
 .Ar
@@ -109,9 +109,6 @@ The
 .Nm
 utility does not treat this as an error.
 No error messages are displayed and the exit value is not affected.
-.It Fl f
-Attempt to force the update, even if the file permissions do not
-currently permit it.
 .It Fl h
 If the file is a symbolic link, change the times of the link
 itself rather than the file that the link points to.
diff --git a/usr.bin/touch/touch.c b/usr.bin/touch/touch.c
index ce507b525e9f..7a613e887d49 100644
--- a/usr.bin/touch/touch.c
+++ b/usr.bin/touch/touch.c
@@ -55,7 +55,6 @@ static const char sccsid[] = "@(#)touch.c	8.1 (Berkeley) 6/6/93";
 #include <time.h>
 #include <unistd.h>
 
-int	rw(char *, struct stat *, int);
 void	stime_arg1(char *, struct timeval *);
 void	stime_arg2(char *, int, struct timeval *);
 void	stime_file(char *, struct timeval *);
@@ -69,12 +68,12 @@ main(int argc, char *argv[])
 	struct timeval tv[2];
 	int (*stat_f)(const char *, struct stat *);
 	int (*utimes_f)(const char *, const struct timeval *);
-	int Aflag, aflag, cflag, fflag, mflag, ch, fd, len, rval, timeset;
+	int Aflag, aflag, cflag, mflag, ch, fd, len, rval, timeset;
 	char *p;
 	char *myname;
 
 	myname = basename(argv[0]);
-	Aflag = aflag = cflag = fflag = mflag = timeset = 0;
+	Aflag = aflag = cflag = mflag = timeset = 0;
 	stat_f = stat;
 	utimes_f = utimes;
 	if (gettimeofday(&tv[0], NULL))
@@ -92,7 +91,7 @@ main(int argc, char *argv[])
 			cflag = 1;
 			break;
 		case 'f':
-			fflag = 1;
+			/* No-op for compatibility. */
 			break;
 		case 'h':
 			cflag = 1;
@@ -222,14 +221,8 @@ main(int argc, char *argv[])
 		 if (!utimes_f(*argv, NULL))
 			continue;
 
-		/* Try reading/writing. */
-		if (!S_ISLNK(sb.st_mode) && !S_ISDIR(sb.st_mode)) {
-			if (rw(*argv, &sb, fflag))
-				rval = 1;
-		} else {
-			rval = 1;
-			warn("%s", *argv);
-		}
+		rval = 1;
+		warn("%s", *argv);
 	}
 	exit(rval);
 }
@@ -368,59 +361,10 @@ stime_file(char *fname, struct timeval *tvp)
 	TIMESPEC_TO_TIMEVAL(tvp + 1, &sb.st_mtim);
 }
 
-int
-rw(char *fname, struct stat *sbp, int force)
-{
-	int fd, needed_chmod, rval;
-	u_char byte;
-
-	/* Try regular files. */
-	if (!S_ISREG(sbp->st_mode)) {
-		warnx("%s: %s", fname, strerror(EFTYPE));
-		return (1);
-	}
-
-	needed_chmod = rval = 0;
-	if ((fd = open(fname, O_RDWR, 0)) == -1) {
-		if (!force || chmod(fname, DEFFILEMODE))
-			goto err;
-		if ((fd = open(fname, O_RDWR, 0)) == -1)
-			goto err;
-		needed_chmod = 1;
-	}
-
-	if (sbp->st_size != 0) {
-		if (read(fd, &byte, sizeof(byte)) != sizeof(byte))
-			goto err;
-		if (lseek(fd, (off_t)0, SEEK_SET) == -1)
-			goto err;
-		if (write(fd, &byte, sizeof(byte)) != sizeof(byte))
-			goto err;
-	} else {
-		if (write(fd, &byte, sizeof(byte)) != sizeof(byte)) {
-err:			rval = 1;
-			warn("%s", fname);
-		} else if (ftruncate(fd, (off_t)0)) {
-			rval = 1;
-			warn("%s: file modified", fname);
-		}
-	}
-
-	if (close(fd) && rval != 1) {
-		rval = 1;
-		warn("%s", fname);
-	}
-	if (needed_chmod && chmod(fname, sbp->st_mode) && rval != 1) {
-		rval = 1;
-		warn("%s: permissions modified", fname);
-	}
-	return (rval);
-}
-
 void
 usage(char *myname)
 {
-	fprintf(stderr, "usage:\n" "%s [-A [-][[hh]mm]SS] [-acfhm] [-r file] "
+	fprintf(stderr, "usage:\n" "%s [-A [-][[hh]mm]SS] [-achm] [-r file] "
 		"[-t [[CC]YY]MMDDhhmm[.SS]] file ...\n", myname);
 	exit(1);
 }