in reply to Re^2: How to enter a filename in each line
in thread How to enter a filename in each line

That method works for a change to a single file but goes a bit pear-shaped if dealing with multiple files. Consider the following.

[johngg@ovs276 perl]$ ls
abc.txt  def.txt
[johngg@ovs276 perl]$ head -99 *
==> abc.txt <==
test text line 1
test text line 2
test text line 3

==> def.txt <==
test text line 1
test text line 2
test text line 3
[johngg@ovs276 perl]$ perl -i.BAK -pe 'BEGIN { $\ = ",$ARGV[0]\n" } ch
+omp' *.txt
[johngg@ovs276 perl]$ ls
abc.txt      abc.txt.BAK  def.txt      def.txt.BAK
[johngg@ovs276 perl]$ head -99 *
==> abc.txt <==
test text line 1,abc.txt
test text line 2,abc.txt
test text line 3,abc.txt

==> abc.txt.BAK <==
test text line 1
test text line 2
test text line 3

==> def.txt <==
test text line 1,abc.txt
test text line 2,abc.txt
test text line 3,abc.txt

==> def.txt.BAK <==
test text line 1
test text line 2
test text line 3
[johngg@ovs276 perl]$
[johngg@ovs276 perl]$
[johngg@ovs276 perl]$ mv abc.txt.BAK abc.txt
[johngg@ovs276 perl]$ mv def.txt.BAK def.txt
[johngg@ovs276 perl]$ ls
abc.txt  def.txt
[johngg@ovs276 perl]$ head -99 *
==> abc.txt <==
test text line 1
test text line 2
test text line 3

==> def.txt <==
test text line 1
test text line 2
test text line 3
[johngg@ovs276 perl]$ perl -i.BAK -pe 's/$/,$ARGV/;' *.txt
[johngg@ovs276 perl]$ ls
abc.txt      abc.txt.BAK  def.txt      def.txt.BAK
[johngg@ovs276 perl]$ head -99 *
==> abc.txt <==
test text line 1,abc.txt
test text line 2,abc.txt
test text line 3,abc.txt

==> abc.txt.BAK <==
test text line 1
test text line 2
test text line 3

==> def.txt <==
test text line 1,def.txt
test text line 2,def.txt
test text line 3,def.txt

==> def.txt.BAK <==
test text line 1
test text line 2
test text line 3
[johngg@ovs276 perl]$

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Note how with your method the second file (and any subsequent files) is annotated the name of the first file processed, which was in the first element of @ARGV. Have a look at $ARGV vs. @ARGV in perlvar.

Cheers,

JohnGG

Replies are listed 'Best First'.
Re^4: How to enter a filename in each line
by repellent (Priest) on Sep 12, 2008 at 22:59 UTC
    Yes, I realized that when I provided the quick-and-dirty solution. With that, I merely wanted to point out the alternative way of changing the output terminator, especially when printing output is of concern.

    Beyond the OP, we really can't tell how thorough a solution is required. For instance, we had to assume that abc.txt was the filename in itself and not part of the file contents.
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Re^4: How to enter a filename in each line
by imran77 (Initiate) on Sep 15, 2008 at 05:16 UTC
    Bundle of thanks to JohnGG, I get what I want. I am not best in perl but now trying to learn steadily form people like you. Can you give some clue how i can do this other than on command line. Regards, Imran
[reply]
      #!/usr/bin/perl
use warnings;
use strict;

$^I = '.BAK';
while ( <> ) {
    s/$/,$ARGV/;
    print;
    }

__END__

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