#!/usr/bin/perl -w

# fix_links.plx

# this script processes all the *.html files whose names are supplied
# to it on the command line, replacing all HREF attributes
# that point to local resources in the current directory
# with rewritten versions that have:
#
# 1) '.htm' extensions changed to '.html', and 
# 2) VaRiEnT captialization uniformly downcased.

foreach $file (@ARGV) {

    unless (-f $file) {
        warn "$file is not a plain file. Skipping...\n";
        next;
    }
    
    unless ($file =~ /\.html$/) {
        warn "$file doesn't end in .html. Skipping...\n";
        next;
    }

    if ($file =~ m{/}) {
        warn "$file contains a slash. Skipping...\n";
        next;
    }
    
    $content = '';
    open IN, $file or die "can't open $file for reading: $!";

    while ($line = <IN>) {
        
        # for HREF attributes pointing to the current directory,
        # downcase attribute, and rename '.htm' to '.html'
        
        $line =~ s/HREF="([^"\/]+\.htm)"/HREF="\L$1\El"/gi;
        
        $content .= $line;
    }

    close IN;
    
    # print $content, to check the changes
    # print "File $file, after changes:\n\n$content\n";

    open OUT, "> $file" or die "can't open $file for writing: $!";
    print OUT $content;
    close OUT           or die "can't close $file after writing: $!";
}