Re^2: Problem in executing the perl oneliner within the script

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Re^3: Problem in executing the perl oneliner within the script (calling perl from perl) by kcott (Archbishop) on Feb 25, 2014 at 16:57 UTC
@reports = `ls .doc`; foreach $file(@reports) { $cmd=`perl -ni -e 'print;print "VALUE=KEY\n" if \$\.== 3;' $file` } [download] 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; $. = 0 if eof; }` [download] I suggest you read "perlrun - how to execute the Perl interpreter". Amongst other things, this will tell you about the Command Switches: perhaps lack of knowledge in this area is why you're coding your script the way you are. I put the above code in `pm_1076103.pl` and created three `.doc` files: `$ 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` [download] I then ran the script like this: `$ pm_1076103.pl .doc` [download] 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` [download] -- Ken	[reply] [d/l] [select]
Re^3: Problem in executing the perl oneliner within the script by 2teez (Vicar) on Feb 25, 2014 at 13:32 UTC
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;` [download] 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 $. == 3; } }` [download] Update If you tell me, I'll forget. If you show me, I'll remember. if you involve me, I'll understand. --- Author unknown to me	[reply] [d/l] [select]
Re^3: Problem in executing the perl oneliner within the script (strict and warnings) by kcott (Archbishop) on Feb 25, 2014 at 16:09 UTC
"In our server there is no stricts and warning in stalled @INC hence unable to use this in my test script." It's not "stricts", it's "strict". I have no "stricts" either: `$ 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.` [download] 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.` [download] Please try these from your command line and report any output: `perl -Mstrict -e 1` [download] `perl -Mwarnings -e 1` [download] 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` [download] -- Ken	[reply] [d/l] [select]