mklink.pl revision 194206 
1#!/usr/local/bin/perl
2
3# mklink.pl
4
5# The first command line argument is a non-empty relative path
6# specifying the "from" directory.
7# Each other argument is a file name not containing / and
8# names a file in the current directory.
9#
10# For each of these files, we create in the "from" directory a link
11# of the same name pointing to the local file.
12#
13# We assume that the directory structure is a tree, i.e. that it does
14# not contain symbolic links and that the parent of / is never referenced.
15# Apart from this, this script should be able to handle even the most
16# pathological cases.
17
18my $pwd;
19eval 'use Cwd;';
20if ($@)
21	{
22	$pwd = `pwd`;
23	}
24else
25	{
26	$pwd = getcwd();
27	}
28
29my $from = shift;
30my @files = @ARGV;
31
32my @from_path = split(/[\\\/]/, $from);
33chomp($pwd);
34my @pwd_path = split(/[\\\/]/, $pwd);
35
36my @to_path = ();
37
38my $dirname;
39foreach $dirname (@from_path) {
40
41    # In this loop, @to_path always is a relative path from
42    # @pwd_path (interpreted is an absolute path) to the original pwd.
43
44    # At the end, @from_path (as a relative path from the original pwd)
45    # designates the same directory as the absolute path @pwd_path,
46    # which means that @to_path then is a path from there to the original pwd.
47
48    next if ($dirname eq "" || $dirname eq ".");
49
50    if ($dirname eq "..") {
51	@to_path = (pop(@pwd_path), @to_path);
52    } else {
53	@to_path = ("..", @to_path);
54	push(@pwd_path, $dirname);
55    }
56}
57
58my $to = join('/', @to_path);
59
60my $file;
61$symlink_exists=eval {symlink("",""); 1};
62foreach $file (@files) {
63    my $err = "";
64    if ($symlink_exists) {
65	unlink "$from/$file";
66	symlink("$to/$file", "$from/$file") or $err = " [$!]";
67    } else {
68	unlink "$from/$file";
69	open (OLD, "<$file") or die "Can't open $file: $!";
70	open (NEW, ">$from/$file") or die "Can't open $from/$file: $!";
71	binmode(OLD);
72	binmode(NEW);
73	while (<OLD>) {
74	    print NEW $_;
75	}
76	close (OLD) or die "Can't close $file: $!";
77	close (NEW) or die "Can't close $from/$file: $!";
78    }
79    print $file . " => $from/$file$err\n";
80}
81