G'day perladdict,

You've been here long enough to know about using the strict and warnings pragmata. Why don't you? In this instance, warnings would have told you:

Use of uninitialized value $. in concatenation (.) or string at ...
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You've also been here long enough to know about posting actual error and warning messages, not some vague or incomplete version. Here's what your code actually produces:

syntax error at -e line 2, near "if =="
  (Might be a runaway multi-line "" string starting on line 1)
Execution of -e aborted due to compilation errors.
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Backticks (`...`) are interpolating quotes: see perlop: Quote-Like Operators. The $. is interpolated as an "uninitialized value" (which warnings tells you); so "if $.==" becomes "if ==" (which the full error message tells you).

That explains the problem; however, why are you starting another perl process? You're already running a perl process — just let it run the code.

Thanks Kcott, based on your detail description for the error message i modified the command as below.
In our server there is no stricts and warning in stalled @INC hence unable to use this in my test script.

@reports = `ls *.doc`;
foreach $file(@reports) {
$cmd=`perl -ni -e 'print;print "VALUE=KEY\n" if \$\.== 3;' $file`
}
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The above code is working fine now, with this i can able to add a line to around 1400 report files.

@reports = `ls *.doc`;
foreach $file(@reports) {
$cmd=`perl -ni -e 'print;print "VALUE=KEY\n" if \$\.== 3;' $file`
}
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The above code is working fine now, with this i can able to add a line to around 1400 report files.

That script will be creating ~1400 perl processes. You've been repeatedly advised about this yet you continue to do it.

This script performs exactly the same function but only uses one perl process:

#!/usr/bin/env perl -i

use strict;
use warnings;

while (<>) {
    print;
    print "VALUE=KEY\n" if $. == 3;
    $. = 0 if eof;
}
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I suggest you read "perlrun - how to execute the Perl interpreter". Amongst other things, this will tell you about the Command Switches: perhaps lack of knowledge in this area is why you're coding your script the way you are.

I put the above code in pm_1076103.pl and created three *.doc files:

$ ls -al *.doc
-rw-r--r--  1 ken  staff  52 26 Feb 03:20 pm_1076103_1.doc
-rw-r--r--  1 ken  staff  52 26 Feb 03:22 pm_1076103_2.doc
-rw-r--r--  1 ken  staff  52 26 Feb 03:22 pm_1076103_3.doc

$ cat pm_1076103_1.doc
Doc 1 Line 1
Doc 1 Line 2
Doc 1 Line 3
Doc 1 Line 4

$ cat pm_1076103_2.doc
Doc 2 Line 1
Doc 2 Line 2
Doc 2 Line 3
Doc 2 Line 4

$ cat pm_1076103_3.doc
Doc 3 Line 1
Doc 3 Line 2
Doc 3 Line 3
Doc 3 Line 4
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I then ran the script like this:

$ pm_1076103.pl *.doc
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Here's what the *.doc files now look like:

$ cat pm_1076103_1.doc
Doc 1 Line 1
Doc 1 Line 2
Doc 1 Line 3
VALUE=KEY
Doc 1 Line 4

$ cat pm_1076103_2.doc
Doc 2 Line 1
Doc 2 Line 2
Doc 2 Line 3
VALUE=KEY
Doc 2 Line 4

$ cat pm_1076103_3.doc
Doc 3 Line 1
Doc 3 Line 2
Doc 3 Line 3
VALUE=KEY
Doc 3 Line 4
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-- Ken

Hi,
"..In our server there is no stricts and warning in stalled @INC hence unable to use this in my test script..."
strict and warnings comes installed with your perl installation. strict since perl 5 and warnings since perl v5.6.0. So if your perl version is newer than the ones i mentioned then you have these pragma installed.
Just use like so

use warnings;
use strict;
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in your perl scripts.
Moreso, I wonder why you are using a oneliner perl with a backtick while you can do all that very simply and clearly like so:
*

use warnings;
use strict;

for my $file ( glob("*.pl") ) {
    open my $fh, '<', $file or die $!;
    while ( defined( $_ = <$fh> ) ) {
        print $_;
        print "adding value=key\n" if $. == 3;
    }
}
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* Update
If you tell me, I'll forget.
If you show me, I'll remember.
if you involve me, I'll understand.
--- Author unknown to me

"In our server there is no stricts and warning in stalled @INC hence unable to use this in my test script."

It's not "stricts", it's "strict". I have no "stricts" either:

$ perl -Mstricts -e 1
Can't locate stricts.pm in @INC (you may need to install the stricts m
+odule) (@INC contains: ...).
BEGIN failed--compilation aborted.
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It's not "warning", it's "warnings". I have no "warning" either:

Can't locate warning.pm in @INC (you may need to install the warning m
+odule) (@INC contains: ...).
BEGIN failed--compilation aborted.
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Please try these from your command line and report any output:

perl -Mstrict -e 1
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perl -Mwarnings -e 1
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If you get no output from those, you have both strict and warnings installed. However, if either produces any output, please run this and report all output:

perl -v
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-- Ken

Hi,
I doubt it if the perl -ni -e 'print; print "adding value=key\n" if $.==3' myfile.txt even run from the CLI without generating a syntax error.
Simply using the below as a script

while (defined($_ = <ARGV>)) {
    print $_;
    print "adding value=key\n" if $. == 3;
}
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