Hello,

I'm sure I have asked this before, but I haven't been able to find where, so apologies for possibly repeating myself.

I have a file that contains environment variables. I want to create a new file in which the environment variables have been expanded. I could obviously get the template file line by line, look for things that look like environment variables, look these up in the %ENV hash, and replace the variable with the value if found. E.g.

use strict;
use warnings;

my $file = shift;

my $undefinedVars = 0;

open(FILE,$file);

while (<FILE>) {
  if (/(\$[^\/\n\t]*)/) {
    my $var = $&;
    my $key = $var;
    substr($key, 0, 1) = "";
    my $val = $ENV{$key};
    if (defined($val)) {
      my $line = $_;
      $line =~ s/\$//g;
      $line =~ s/$key/$val/g;
      print $line;
    } else {
      $undefinedVars++;
    }
  } else {
    print $_;
  }
}

close(FILE);

if ($undefinedVars > 0) {
  print "ERROR: There were $undefinedVars undefined variables!\n";
}
[download]

This input looks (something) like this:

bigcompany.product.part.widgit=$WIDGIT
bigcompany.product.part.battery=$BATTERY
bigcompany.product.part.frobnicator=$FROBNICATOR
bigcompany.product.part.blorpdata=$BLORP/data
[download]

But I feel there must be a simpler way. Any ideas?

Thanks,

loris

Update 1: Added code

Update 2: Added input

Update 3: Added missing case to input