I think I understand this part of your description:

if value exist in file1 and found in file2 than take both lines containing that value and merge into one single file

But there's nothing in your code to support this kind of operation. What is the value that you're looking for in the two input files?

It looks like both input files are lists of table-like data, with three fields per line ("id up down"). If the value you're looking for is unique to one "cell" in each table (that is, it would occur only once per input file, if at all), then you're really talking about doing a "grep" operation. In fact, if you're using a unix-like OS, just use the "grep" command-line utility; if you're using MS-Windows, there are versions of grep available for free.

But if you want to see how it's done in perl, here's one way:

#!/usr/bin/perl

use strict;

my $Usage = "Usage: $0 value file1 file2\n";
die $Usage unless ( @ARGV == 3 and -f $ARGV[1] and -f $ARGV[2] );

my $value = shift;  # removes first element from @ARGV

my @match;  # will hold matching line from each file

for my $file ( @ARGV ) {  # loop over remaining two ARG's
    open( IN, $file ) or die "$file: $!";
    while (<IN>) {
        if ( /$value/ ) {
            chomp;
            push @match, $_;
            last;
        }
    }
}

print join( " ", @match ), "\n";
[download]

Now, if you were to try using the unix "grep" command, it would be:

 grep value file1 file2
[download]

Note that both the perl script and the grep command shown above will output the matching lines to STDOUT (the grep command will not join the two into a single line -- it will also include the file name at the beginning of each line, to show where the line came from).

Also, your output might not be what you expect, if the value you're searching for contains characters that have special meanings in a regex (period, plus-sign, asterisk, question mark, brackets, braces, parens, "^", "$", "@" or "%", some others, depending on context). For such things, put "\Q" and "\E" around $value in the perl script.

If you want the matches to be saved in a separate file, just use redirection on the command line:

  perlscript value file1 file2 > matched.lines
# or
  grep value file1 file2 > matched.lines
[download]

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.