this:

 my @nonempty_files = grep { ! -z $_ } @files;
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looks not very trustworthy ;-). This might be wrong. Compare some test schenarios with this approach:

 ...
 my @nonempty_files = grep -e && !-z, @files;
 ...
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(especially for non-accessible and non-existent files.)

Regards

mwa

@files = grep { /\.log$/ } readdir ($DIR);
foreach my $x (@files){
open READFILE, "......";
open WRITEFILE, ">......";
while(<READFILE>){
chomp;
my @parts = split(/\s/, $_);
print WRITEFILE $parts[1], " ", $parts[0], "\n";
}
close WRITEFILE;
close READFILE;
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Your code won't compile. That's not very dire. Just stay comitted to it ;-)

use strict;
use warnings;

my $path = '/tmp/allfiles';
my $outpath = '/tmp/nonemptyfiles';
opendir my $dh, $path or die $!;
my @files = grep /\.log$/ && -f "$path/$_" && !-z "$path/$_", readdir 
+$dh;
closedir $dh;

for my $fn (@files){
   open my $fr, '<', "$path/$fn" or die "IN: $fn $!";
   open my $fw, '>', "$outpath/$fn" or die "OUT: $fn $!";;
   while( <$fr> ) {
      printf $fw "$1 $2\n" if /(\S+)\s+(\S+)/
   }
}
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Try to study the example and bear some idomatic expressions in mind like indirect file handles and checks for success ...

Regards

mwa

#!/usr/bin/perl
$dest="/home/perl/sra/";
print "the source direcotry name:\n";
chomp(my $source=<STDIN>);
opendir($DIR, $source)
or die "cannot open the directory '$source': $!";
@files =@files = grep { /\.log$/ } readdir ($DIR);
foreach my $x (my @files){
open READFILE, "$source/$x";
open WRITEFILE, ">$dest$x";
while(<READFILE>){
chomp;
my @parts = split(/\s/, $_);
print WRITEFILE $parts[1], " ", $parts[0], "\n";
}
close WRITEFILE;
close READFILE;
}
closedir($DIR)
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this code works out but the options given by you for selecting and copying only non empty files doesnt work out!! please help me out!!

@files = grep { /\.c$/ } readdir ($DIR);
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