From 3d022151d73ca2bb9d6caf5c2151247cc61f64fa Mon Sep 17 00:00:00 2001
From: Ward Wouts <ward@wouts.nl>
Date: Tue, 5 Feb 2002 21:11:23 +0000
Subject: [PATCH] clean up locks a little better

---
 mvwrap/mvwrap | 57 ++++++++++++++++++++++++++++++---------------------
 1 file changed, 34 insertions(+), 23 deletions(-)

diff --git a/mvwrap/mvwrap b/mvwrap/mvwrap
index 2e4cde8..20d917c 100755
--- a/mvwrap/mvwrap
+++ b/mvwrap/mvwrap
@@ -14,9 +14,10 @@ use File::Copy;
 use POSIX qw(tmpnam);
 use Getopt::Long;
 
+&lock;
+
 &cmdline;
 unless (defined @source) { @source = &read_cur_dir; }
-&lock;
 
 if (@pattern) {
 	@target = @source;
@@ -51,7 +52,7 @@ if (@unsafe = &check_safety(\@source, \@target)) {
 #Read current dir
 sub read_cur_dir {
 	my (@dir, $filename);
-	opendir(DIRHANDLE, ".") or die "couldn't open .: $!";
+	opendir(DIRHANDLE, ".") or &cdie("couldn't open .: $!\n");
 	while ( defined ($filename = readdir(DIRHANDLE)) ) {
 		unless ($filename eq "." | $filename eq "..") {
 			chomp ($filename);
@@ -69,7 +70,7 @@ sub edit {
 	@editor = (defined $ENV{EDITOR}  ? $ENV{EDITOR} : "vi", "$filename");
 	if ($opt_e) { @editor = ($opt_e, "$filename") }
 	system(@editor) == 0
-		or die "System @editor failed: $!";
+		or &cdie("System @editor failed: $!");
 }
 
 # make tempfiles and install handler to remove them
@@ -77,7 +78,7 @@ sub open_temp {
 	my $target;
 	do { $target_name = tmpnam() }
 		until $target = IO::File->new($target_name, O_RDWR|O_CREAT|O_EXCL);
-	END { if ($opt_e) { unlink($target_name) or die "Couldn't unlink $target_name: $!";} }
+	END { if ($opt_e) { unlink($target_name) or &cdie("Couldn't unlink $target_name: $!");} }
 	foreach (@source) {
 		print $target "$_\n";
 	}
@@ -87,7 +88,7 @@ sub open_temp {
 
 sub read_temp {
 	my $target_name = shift;
-	open TARGET, $target_name or die "Couldn't open tempfile: $target_name: $!";
+	open TARGET, $target_name or &cdie("Couldn't open tempfile: $target_name: $!");
 	foreach (<TARGET>) {
 		chomp;
 		push @target, $_;
@@ -110,7 +111,7 @@ sub move_files {
 			}
 			unless ($opt_n) {
 				move("$source", "$target")
-					or die "move failed: $!";
+					or &cdie("move failed: $!");
 			}
 		}
 	}
@@ -118,7 +119,7 @@ sub move_files {
 
 # read pattern file
 sub read_pattern {
-	open PAT, "< $opt_f" or die "Couldn't open pattern file: $!\n";
+	open PAT, "< $opt_f" or &cdie("Couldn't open pattern file: $!\n");
 	@pattern = <PAT>;
 	close PAT;
 }
@@ -139,20 +140,17 @@ sub pattern_edit {
 sub run_checks {
 	my $line;
 	unless ( scalar(@source) == scalar(@target) ) {
-		if ( -e ".mv_wrap" ) { unlink (".mv_wrap"); }
-		die "Aborting. Source and target list don't have the same number of lines.\n";
+		&cdie("Aborting. Source and target list don't have the same number of lines.\n");
 	}
 	
 	foreach $line (@target) {
 		if ( $line =~ m/^$/ ) {
-			if ( -e ".mv_wrap" ) { unlink (".mv_wrap"); }
-			die "Aborting. You can't move to empty names.\n";
+			&cdie("Aborting. You can't move to empty names.\n");
 		}
 	}
 	
 	if ( &check_unique(@target) ) {
-		if ( -e ".mv_wrap" ) { unlink (".mv_wrap"); }
-		die "Aborting. You're trying to move multiple files to the same name.\n";
+		&cdie("Aborting. You're trying to move multiple files to the same name.\n");
 	}
 }
 
@@ -219,7 +217,7 @@ sub safety_belt {
 		}
 		unless ($opt_n) {
 			move("$filename", "$rand")
-				or die "move failed: $!";
+				or &cdie("move failed: $!\n");
 		}
 		$source->[$filenr] = "$rand";
 	}
@@ -236,27 +234,41 @@ sub paranoia {
 		foreach $csource (@$source) {
 			if ($ctarget eq $csource) { $safe = 1; }
 		}
-		if (! $safe && -e $ctarget) { die "That would overwrite files\n"; }
+		if (! $safe && -e $ctarget) { &cdie("That would overwrite files\n"); }
 	}
 }
 
+# lock, unlock and cdie are the only subs that should use die;
+# all others should use &cdie. A handler for this would probably
+# be nicer.
+
+# place lockfile in dir, or exit if one exists.
 sub lock {
-	if ( -e ".mv_wrap") {
-		die "Another mv_wrap process is active in this direcory\n"
+	if ( -e ".mvwrap") {
+		die "Another mvwrap process is active in this direcory\n"
 	}
 	else {
-		open LOCK, "> .mv_wrap" or die "Couldn't open .mv_wrap for writing: $!\n";
+		open LOCK, "> .mvwrap" or die "Couldn't open .mvwrap for writing: $!\n";
 		print LOCK $$;
 		close LOCK;
 	}
 }
 
+# clean up lockfile
 sub unlock {
-	if ( -e ".mv_wrap" ) {
-		unlink(".mv_wrap") or die "Couldn't remove lock file: $!\n";
+	if ( -e ".mvwrap" ) {
+		unlink(".mvwrap") or die "Couldn't remove lock file: $!\n";
 	}
 }
 
+# clean up lock & die
+sub cdie {
+	$message = shift;
+	&unlock;
+	die "$message";
+}
+
+# parse commandline
 sub cmdline {
 	%optctl = ();
 	&GetOptions("e=s", "h", "p=s", \@pattern, "f=s", "v", "n");
@@ -272,6 +284,7 @@ sub cmdline {
 	}
 }
 
+# show help message
 sub help {
 	$opt_h = 1; # just get rid of that stupid message from -w
 	print << "EOT";
@@ -291,9 +304,7 @@ At the moment it takes the following options:
 -v			verbose; shows file moves
 -n			test; doesn't move, implies -v
 
-Specifying files on the command line is still unsafe! There are no checks
-to prevent overwriting non-specified files!
-
 EOT
+&unlock;
 exit;
 }