Perl file and STDERR

[jitendra B]

Hi All,


Can you please let me know the following snippset? why it is used for?


select( STDERR );
$| = 1;
select( STDOUT );
$| = 1;
print STDERR "\nThis is india\n\n";
 print STDERR "Usage: This is build";
 print STDERR "where: base PL label\n";

and second question
****************
 second question:- I want to open a file read+write mode and change the
some content in same file without creating another file and copy to it.

MY SCRIPT(Not working as i wish to )
********************
#!/usr/bin/perl

open(FILE,">test.txt") or die "Could not open the file: $!";

@file=<FILE>;

foreach (@file)
{
      $_=~s/BLR/bangalore/g;

      print "$_";
}
close(FILE);

Regards,
Jitendra