diff --git a/png2c.pl b/png2c.pl
index b6092ef..d98f635 100644
--- a/png2c.pl
+++ b/png2c.pl
@@ -1,34 +1,43 @@
-#!/usr/bin/perl
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
 
 use GD;
 
-my ($out, $proto) = @ARGV;
+my ($out, $proto, $srcdir) = @ARGV;
+defined($srcdir) or $srcdir = '.';
+-d "$srcdir/icons" || die "$srcdir/icons/: directory not found";
+
 open(OUT, ">$out") or die "$out: $!";
 open(PROTO, ">$proto") or die "$proto: $!";
 
-for $file (<icons/*.png>) {
-    next if $file =~ /char-/;
+print OUT   "/**** This is a generated file - do not edit ****/\n\n";
+print PROTO "/**** This is a generated file - do not edit ****/\n\n";
 
-    $file =~ m#.*/(.*)\.png#;
-    $base = "Icon_$1";
+for my $file (<$srcdir/icons/*.png>) {
+    next if $file =~ m#/char-[^/]+$#;
+
+    $file =~ m#/([^/]+)\.png$#;
+    my $base = "Icon_$1";
     $base =~ y/-/_/;
 
     open(PNG, $file) or die "$file: $!\n";
-    $img = newFromPng GD::Image(\*PNG) or die;
+    my $img = newFromPng GD::Image(\*PNG) or die;
     $img->trueColor(1);
 
     close PNG;
 
-    ($width, $height) = $img->getBounds();
+    my ($width, $height) = $img->getBounds();
     die "$file: $width, $height"  if ($width != 24) or ($height != 24);
 
-    print PROTO "extern unsigned char $base\[24*24*3\];";
+    print PROTO "extern unsigned char $base\[24*24*3\];\n";
     print OUT "unsigned char $base\[24*24*3] = {\n";
 
-    for($y = 0; $y < 24; $y++) {
-        for($x = 0; $x < 24; $x++) {
-            $index = $img->getPixel($x, 23-$y);
-            ($r, $g, $b) = $img->rgb($index);
+    for(my $y = 0; $y < 24; $y++) {
+        for(my $x = 0; $x < 24; $x++) {
+            my $index = $img->getPixel($x, 23-$y);
+            my ($r, $g, $b) = $img->rgb($index);
             if($r + $g + $b < 11) {
                 ($r, $g, $b) = (30, 30, 30);
             }
@@ -37,5 +46,7 @@ for $file (<icons/*.png>) {
     }
 
     print OUT "};\n\n";
-
 }
+
+close PROTO;
+close OUT;
diff --git a/pngchar2c.pl b/pngchar2c.pl
index 99ce60f..8462c2b 100644
--- a/pngchar2c.pl
+++ b/pngchar2c.pl
@@ -1,20 +1,29 @@
-#!/usr/bin/perl
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
 
 use GD;
 
-for $file (sort <icons/char-*.png>) {
+my ($srcdir) = @ARGV;
+defined($srcdir) or $srcdir = '.';
+-d "$srcdir/icons" || die "$srcdir/icons/: directory not found";
+
+print "/**** This is a generated file - do not edit ****/\n\n";
+
+for my $file (sort <$srcdir/icons/char-*.png>) {
     open(PNG, $file) or die "$file: $!\n";
-    $img = newFromPng GD::Image(\*PNG) or die;
+    my $img = newFromPng GD::Image(\*PNG) or die;
     $img->trueColor(1);
     close PNG;
 
-    ($width, $height) = $img->getBounds();
+    my ($width, $height) = $img->getBounds();
     die "$file: $width, $height"  if ($width != 16) or ($height != 16);
 
-    for($x = 0; $x < 16; $x++) {
-        for($y = 0; $y < 16; $y++) {
-            $index = $img->getPixel($x, $y);
-            ($r, $g, $b) = $img->rgb($index);
+    for(my $x = 0; $x < 16; $x++) {
+        for(my $y = 0; $y < 16; $y++) {
+            my $index = $img->getPixel($x, $y);
+            my ($r, $g, $b) = $img->rgb($index);
             if($r + $g + $b < 11) {
                 print "  0, ";
             } else {