copy-if-different.pl revision 326663 
1#!/usr/local/bin/perl
2
3use strict;
4
5use Fcntl;
6
7# copy-if-different.pl
8
9# Copy to the destination if the source is not the same as it.
10
11my @filelist;
12
13foreach my $arg (@ARGV) {
14	$arg =~ s|\\|/|g;	# compensate for bug/feature in cygwin glob...
15	$arg = qq("$arg") if ($arg =~ /\s/);	# compensate for bug in 5.10...
16	foreach (glob $arg)
17		{
18		push @filelist, $_;
19		}
20}
21
22my $fnum = @filelist;
23
24if ($fnum <= 1)
25	{
26	die "Need at least two filenames";
27	}
28
29my $dest = pop @filelist;
30
31if ($fnum > 2 && ! -d $dest)
32	{
33	die "Destination must be a directory";
34	}
35
36foreach (@filelist)
37	{
38        my $dfile;
39	if (-d $dest)
40		{
41		$dfile = $_;
42		$dfile =~ s|^.*[/\\]([^/\\]*)$|$1|;
43		$dfile = "$dest/$dfile";
44		}
45	else
46		{
47		$dfile = $dest;
48		}
49
50	my $buf;
51	if (-f $dfile)
52		{
53		sysopen(IN, $_, O_RDONLY|O_BINARY) || die "Can't Open $_";
54		sysopen(OUT, $dfile, O_RDONLY|O_BINARY)
55		  || die "Can't Open $dfile";
56		while (sysread IN, $buf, 10240)
57			{
58			my $b2;
59			goto copy if !sysread(OUT, $b2, 10240) || $buf ne $b2;
60			}
61		goto copy if sysread(OUT, $buf, 1);
62		close(IN);
63		close(OUT);
64		print "NOT copying: $_ to $dfile\n";
65		next;
66		}
67      copy:
68	sysopen(IN, $_, O_RDONLY|O_BINARY) || die "Can't Open $_";
69	sysopen(OUT, $dfile, O_WRONLY|O_CREAT|O_TRUNC|O_BINARY)
70					|| die "Can't Open $dfile";
71	while (sysread IN, $buf, 10240)
72		{
73		syswrite(OUT, $buf, length($buf));
74		}
75	close(IN);
76	close(OUT);
77	print "Copying: $_ to $dfile\n";
78	}
79
80