For most uses, you'll probably be satisfied with the solutions above, where you decompress the .gz file into memory and "operates" on the uncompressed content as you wish.

But if you need to deal with really big files or if the operations you'll need to apply prefer the content in a file (eg. when you need to pass it to external programs), you can do it with a combination of Archive::Extract and File::Temp. The following code is such an example:

use File::Temp ();
use Archive::Extract ();

for my $gz ( @ARGV ) {

  my $tmp = File::Temp->new();

  my $ae = Archive::Extract->new( archive => $gz );
  my $ok = $ae->extract( to => $tmp->filename );
  die $ae->error unless $ok;

  # do what you want to the uncompressed content in the
  # file named $tmp->filename
  ...
  # at the end of the scope, $tmp vanishes 
}
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This code has the bonus of working with other compressed types, like .bz2, .Z and even .lzma with the latest release of Archive::Extract. Even more, because this module may also extract archives with multiple files like .tar.gz, .zip, etc.

did this code work for u.When i tried its showing an error like "It looks like you don't have a C compiler on your PATH, so you will not be able to compile C or XS extension modules. You can install GCC from the MinGW package using the Perl Package Manager by running: ppm install MinGW"

I tried installing using the above command.But installation is getting failed

When i tried its showing an error like

It is not only an error message, it is instructions to overcome the error!!!!!!

Cheers,

JohnGG

Update: I'm not sure what I was on when I wrote that nonsense about .zip files. I have, of course, used Compress::Zlib on .gz files, it was Archive::Zip that I used on .zip files.

use strict;
use PerlIO::gzip;

( @ARGV == 1 and -f $ARGV[0] and $ARGV[0] =~ /\.gz$/ )
    or die "Usage: $0  file.gz\n";

open( IN, "<:gzip", $ARGV[0] ) or die "open failed on $ARGV[0]: $!\n";
while (<IN>) {
    # $_ contains one line of uncompressed text data per iteration
    do_something($_);
}
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UPDATE: (2010-10-18) It seems that PerlIO::gzip should be viewed as superseded by PerlIO::via:gzip. (see PerlIO::gzip or PerlIO::via::gzip).