In general, the script should look something like this:

while (<ARGV>) {
   print if /some_regexp/;
}
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print "$1 $2 (..etc)\n" if /some regexp with captures/;
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Ritu says: Hi i dont no anything about PERL, only read a beginners online tutorial.

You might want to continue reading this site's Tutorials to learn some more?

There are output data files which some simulation runs are generating. I need a simple perl script to extract results from the files using perl script and use it to plot graphs in gnuplot. Can anybody please help me.

my @output_data_files = qw( filename1 filename2 more_filenames... );
my $pattern = qr/result/; # a regular expression that will find "resul
+t"

my @results_found;        # here goes everything that was found.

foreach my $file ( @output_data_files ) {
    open ( FILE, "< $file" )
      or die qq(could not open file "$file" for reading: $!);

    while ( <FILE> ) {    # on every line of the file
        if ( my @matches = m/$pattern/g ) { # matches of the pattern
            push @results_found, @matches;  # add them to @results_fou
+nd
        }
    }
    close FILE;
}
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Now you have got the results in the array   @results_found.
Tell us how gnuplot expects the data and we might know how to proceed from here.

Cheerio, Sören