Please show some data and the code you've tried, so we can help you.

as a very general hint, see:

perldoc -f index
perldoc -f sort
perldoc perlre
[download]

-- 
Joost       downtime n. The period during which a system
            is error-free and immune from user input.
[download]

This is the datafile of space delimited.
1 fruit apple,pear
2 fruitloop orange,yellow
3 fruitcake yummy,bad
4 car bug,volvo,toyota,jag

#!/usr/bin/perl -w
use strict;
my $keywordcol = 2; # keywords are in this column
my $wordpattotest = '\wag';
my $wordtotest = 'orange';
my $datafilename = 'in.dat';
open(IN,$datafilename);
my @data;
while(<IN>) {
    my (@fields) = split(/\s+/,$_); 
    # if you wanted to have data separated by tabs, replace \s with \t
+, 
    # remove the '+' if you don't want multiple consecutive 
    # separators to be treated as one.

    if( $fields[$keywordcol] =~ /$wordpattotest/ ) {
    print;
    }
    # or if you wanted to find exact words you could loop
    # over the keywords
    foreach my $w ( split(/,/,$fields[$keywordcol] ) ) {
    print if( $w eq $wordtotest);
    }
    push @data, \@fields;
}

# If you wanted to sort the data by a specific column
my $coltosort = 1;
foreach my $row ( sort { $a->[$coltosort] cmp $b->[$coltosort] } @data
+ ) { 
# replace cmp with <=> if data is numeric
 print join(' ', @$row), "\n"
}
[download]