What do you mean by "chomp [is] not working"? chomp removes \n (or whatever $/ holds) form the end of the string, if present.

I'd say the likelyhood of chomp not working is nil. The following questions should help you find the real problem:

• Does $/ contain \n (and just that)?
  Test: die("Bad \$/\n") if $/ ne "\n";
• Does the string end with \n?
  Test: die("String doesn't end with \\n\n") if $line !~ /\n\z/;
• Is there only one \n at the end of the string?
  Test: die("String has multiple \\n\n") if $line =~ /\n.*\n/s;
• Are you sure there isn't any other special characters (such as \r) at the end of the string or before the \n?
  Test: die("String has \\r\n") if $line =~ /\r/;

Update: Added test snippets.

I don't if the string end with line , I am giving the output as it is and trying to print the line as it is then next to the line I need to write valid or not valid . how ever if I try to type valid next to the line it will go to the next line no matter what I do :

print "$line valid\n";
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will look somthing like this one % ...... valid

Run

$line = "one % : thrre blblblb % 545334\n";
chomp($line);
print "$line valid\n";
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If you get

one % : thrre blblblb % 545334 
valid
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then someting is really wrong with your perl.

If you get,

one % : thrre blblblb % 545334 valid
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then chomp is working and my previous post stands. Answer the questions in my previous post if you want to find the problem. I've just added code snippets in that post to help you answer the questions.

Could this be a Windows to UNIX text file transfer problem? Hidden characters used in Windows text files can do strange things in UNIX. There is an EMBOSS program that will strip these for you.

How about posting a small code snippet that shows the problem. I suggest you use the following template as a starting point:

use strict;
use warnings;

while (<DATA>) {
    chomp;
    print ">$_<\n";
}

__DATA__
test data that chomps fine.
Your manky data that fails for a chomp
A nicely chomped line
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Prints:

>test data that chomps fine.<
>Your manky data that fails for a chomp<
>A nicely chomped line<
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$ perl -e '$_=qq{one % : thrre blblblb % 545334\n};chomp;print "!!$_!!
+\n"; print "Erm...\n"'
!!one % : thrre blblblb % 545334!!
Erm . . .
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