This little snippet uses a Module that exports a multidimensional hash. In my case this contains some configuration for various perl programs that are all part of the same project.

To use this configuration from other C programs, too, this hash is written to a C header file that takes the names of the hash and makes a string with lots of underscores in it... This is done recursively :)

# this contains the hash %global_conf
use GlobalConf;

$headerfile = "global_conf.h";

open HEAD, ">$headerfile" or die
  "could not write header file\n$!";

# Intro
print HEAD "/* global configuration for the XXXX project\n",
  " * automatically generated with pm2h from GlobalConf.pm \n */\n\n";
print HEAD "# ifndef GLOBAL_CONF_HH_INCLUDED\n",
  "# define GLOBAL_CONF_HH_INCLUDED\n\n";

recurse_hash(\%global_conf,"global_conf",0);

print HEAD "\n# endif\n";
close HEAD;
exit 0;

# recursively traverse the hash
sub recurse_hash {
  my ($hashref,$string_so_far,$depth) = @_;
  my $indent = "  " x $depth; 
  my $string = $string_so_far;
  my %hash = %{ $hashref };

  foreach $key (keys %hash) {
    if (ref($hash{$key})) {
      recurse_hash($hash{$key},$string."_$key",$depth+1);
    } else {
      print HEAD "static char ",$string."_$key","[] = \"$hash{$key}\";
+\n";
          # for debug
      #print $indent,$string."_$key","[] = \"$hash{$key}\";\n";
    }
  }  
}

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In reply to Hash To C-Header - Recursive by stefan k

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