CODEWITHSUNDEEP
perlcommand-line
Devaki
Devaki

Reputation: 19

grep word in text files using perl

I have a text file A00010.txt A00011.txt A00012.txt to A00099.txt in myfolder which contains different entries like,

umxwtdn8vtnt_n
umxwtdtnt_nn8v
umxwt_ntdn8vtn
u8vtnt_nmxwtdn
utnt_nmxwtdn8v

my perl code is

#!/usr/bin/perl
use strict;

        my $count = 10; 
        for ($count = 10; $count<= 99; $count++) { 
            my $result = `/bin/cat /myfolder/A000$count.txt  | grep "umxwtdn8vtnt_n"`;
            return $result;
        }

     print $result;

i trying to get $result value but show empty

Upvotes: 1

Views: 1861

Answers (2)

sebnukem
sebnukem

Reputation: 8323

Do you really need to use Perl?

If not:

find /myfolder -name "A000??.txt" | xargs grep -n "umxwtdn8vtnt_n"

Will find the pattern in your files and tell you at which line...

Would you like to know if the pattern is in one or more of your files? Then:

 my $not_found = 1;
 for (my $count = 10; $count<= 99; $count++) { 
    my $result = `grep "umxwtdn8vtnt_n" /myfolder/A000$count.txt`;
    if ($result) {
        print $result;
        $not_found = 0; # error level 0 = no error = found
        last;
    }
 }
 exit $not_found; # error level 1 = error = not found

Still trying to understand your need... what about:

my $result;
for (my $count = 10; $count<= 99; $count++) { 
   # you should test that A000$count.txt actually exists here
   my $match = `grep "umxwtdn8vtnt_n" /myfolder/A000$count.txt`;
   if ($match == "umxwtdn8vtnt_n") {
        print "found $match in A000${count}.txt";
        $result = $match;
        last; # exit for loop
    }
}
if ($result) {
    # do something with it?
}

Upvotes: 2

Ming-Tang
Ming-Tang

Reputation: 17651

Is /myfolder really in the root directory? (what do you see in ls /? Do you see myfolder?) It's very rare to add things in the root directory in a Unix system, and I don't think you are messing with /.

Also, you are returning $result outside a subroutine (sub { }), and if that's the case, you should get a Perl runtime error.

If you are copying code fragments, then please note that $result is a local variable and it disappears after a subroutine ends.

Upvotes: 3

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