Example

The following is an example of an external rewriting program rewrite.pl, used to change the prefix /home/ to /u/:

#!/usr/bin/perl
$| = 1;
while (<STDIN>) {
    s|^/home/|/u/|;
    print $_;
}

In this example, the external expression function used to invoke rewrite.pl is as follows:

NameTrans fn="rewrite" path="$(external('rewrite.pl', $path))"