A faster (and more general, and better documented) replacement for mklink.sh.

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Reviewed by:
PR:

diff --git a/util/mklink.pl b/util/mklink.pl
new file mode 100755 (executable)
index 0000000..9f48925
--- /dev/null
+++ b/util/mklink.pl
@@ -0,0 +1,52 @@
+#!/usr/local/bin/perl
+
+# mklink.pl -- a faster substitute for mklink.sh.
+
+# The first command line argument is a non-empty relative path
+# specifying the "from" directory.
+# Each other argument is a file name not containing / and names
+# a file in the current directory.
+#
+# For each of these files, we create in the "from" directory a link
+# of the same name pointing to the local file.
+#
+# We assume that the directory structure is a tree, i.e. that does not
+# contain symbolic links and that the parent of / is never referenced.
+# Apart from this, this script should be able to handle even the most
+# pathological cases.
+
+my $from = shift;
+my @files = @ARGV;
+
+my @from_path = split(/\//, $from);
+my $pwd = `pwd`;
+chop($pwd);
+my @pwd_path = split(/\//, $pwd);
+
+my @to_path = ();
+foreach my $dirname (@from_path) {
+
+    # In this loop, @to_path always is a relative path from
+    # @pwd_path (interpreted is an absolute path) to the original pwd.
+
+    # At the end, @from_path (as a relative path from the original pwd)
+    # designates the same directory as the absolute path @pwd_path,
+    # which means that @to_path then is a path from there to the original pwd.
+
+    next if ($dirname eq "" || $dirname eq ".");
+
+    if ($dirname eq "..") {
+       @to_path = (pop(@pwd_path), @to_path);
+    } else {
+       @to_path = ("..", @to_path);
+       push(@pwd_path, $dirname);
+    }
+}
+
+my $to = join('/', @to_path);
+
+foreach my $file (@files) {
+#    print "ln -s $to/$file $from/$file\n";
+    symlink("$to/$file", "$from/$file");
+    print $file . " => $from/$file\n";
+}