#!/usr/bin/perl

# First extract the include lines from each file.

foreach $file (@ARGV) {
    open(FILE, $file) || warn "Can't open $file: $!\n";
    while (<FILE>) {
	if (/^#include\s+["<]([^">]*)[">]/) {
	    $included = $1;
	    $includes{$file} .= $included . ' ';
	}
    }
}

# Now print them out in sorted order.

foreach $target (sort keys(%includes)) {
    $dependencies = $includes{$target};
    foreach $dependency (split(/ /, $dependencies)) {
	print "$target: $dependency\n";
    }
}
