Why does this Perl code work from the shell, but not from a script?

Question

I have a simple question. I have been using the zoidberg perl shell to get myself familiarized with perl interactively. I like being able to test my stuff on the fly before I flesh out a script. (I am a novice learner.)

My question is, in the shell I can do the following:

@a = `df -h | grep /dev/mapper | cut -c 48-`

for $i (@a) { @b=`ls $i` }
print @b;

However, when I put this in a script in linux:

#!/bin/perl

I see the following error when I run the script:

syntax error at perl_diskstats.perl line 5, near "$i ( "
Execution of perl_diskstats.perl aborted due to compilation errors.

Am I doing something obvious here? What exactly am I doing wrong? I thought the format was..

foreach $var (@array) { codeblock }

... right?

You're missing a semi-colon at the end of your first line.

ire_and_curses
– ire_and_curses

2012-06-13 22:29:20 +00:00
Commented Jun 13, 2012 at 22:29 — ire_and_curses
– ire_and_curses, Commented Jun 13, 2012 at 22:29
holy moly you are awesome, and I am so dumb thank you!

slugman
– slugman

2012-06-13 22:30:16 +00:00
Commented Jun 13, 2012 at 22:30 — slugman
– slugman, Commented Jun 13, 2012 at 22:30
@ire_and_curses You should make that comment an answer.

TLP
– TLP

2012-06-13 22:57:04 +00:00
Commented Jun 13, 2012 at 22:57 — TLP
– TLP, Commented Jun 13, 2012 at 22:57

ire_and_curses · Accepted Answer · 2012-06-13 23:06:02Z

7

You're missing a semi-colon at the end of your first line.

answered Jun 13, 2012 at 23:06

ire_and_curses

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Comments

LeoNerd · Accepted Answer · 2012-06-14 09:30:10Z

0

Also you are missing use strict, and the my declarations.

use strict;

my @a = `df -h | grep /dev/mapper | cut -c 48-`;

my @b;
for my $i (@a) { @b=`ls $i` }

print @b;

Start off on the habit of use strict now, while you're still beginning. It will save you in the longterm.

answered Jun 14, 2012 at 9:30

LeoNerd

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