Shell Programming and Scripting

Hi Madhan,

No..Its taking double the time...

Script:

#!/usr/local/bin/perl
open(FILE, "<", $ARGV[0]) || die ("unable to open <$!>\n");
while( read(FILE, $data, 1000) == 1000) {
$stat=0;
@char = split(//,$data);
foreach (@char){
print "@char[$stat]" if((ord(@char[$stat])>=32)&&(ord(@char[$stat])<=126));
print "\n" if(ord(@char[$stat])==10);
$stat++;
}
}
# for processing last batch
$stat=0;
@char = split(//,$data);
foreach (@char){
print "@char[$stat]" if((ord(@char[$stat])>=32)&&(ord(@char[$stat])<=126));
print "\n" if(ord(@char[$stat])==10);
$stat++;
}
close(FILE);

So I am reverting back to the old logic that took 10 mins for 300 MB file.

Please let me know if anything else can be done.

Thank you for your support and help on this..

Code:

#!/usr/local/bin/perl
use warnings;
use strict;
$ARGV[0] or die "Need a filename\n";
while(<>) {
   foreach my $t (split(//)){
      my $ord = ord $t;
      print $t if ( $ord >= 32 && $ord <= 126);
   }
   print "\n";
}

Perl actually has pretty efficient internal optimizations for this kind of stuff.

If you are really into optimization, you can calculate a baseline by running just perl -ne 1 on the file and then see how much your additional processing takes time. Add some more steps piecemeal and see if there are any really big jumps in the stats. If there are, figure out if you are disabling some internal optimization and if rephrasing the code can get it back.

Can you split the processing, like tr -d '\000-\037\200-\377' <file | perl ... and get away with it?

(Or '\000-\011\013-\037\200-\377' if you want to preserve the newlines, like matrixmadhan observed.)

Duh, actually, newline is '\012', sorry for the brain fart. ('\010' is tab, might want to keep that too, tho.)

// Edited the posting to correct it there.