IPstacks has asked for the wisdom of the Perl Monks concerning the following question:

Okay... I've been a perl monk for all of a few hours. I have been reading the O'Reilly press book and have made some progress. My basic question is I am trying to open a file and read in the contents and then close the file (haven't even tried to print it yet). The problem is that I get this error:

root@ns1 /root# ./script.pl
Global symbol "@data" requires explicit package name at ./script.pl line 7.
Execution of ./script.pl aborted due to compilation errors. 
#!/usr/bin/perl -w
use strict;

my $filename = "/root/estimates.foo.com"; # declare filename

open FILE, $filename or die "Can't open file: $!/n";
@data=<FILE>;
close FILE;

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From everything that I've read, this looks fine. Any help would be appreciated!

Replies are listed 'Best First'.
Re: File Open Question
by perigeeV (Hermit) on Nov 14, 2001 at 07:51 UTC

    root@ns1 /root# ./script.pl

    Please don't play with Perl while running as root. Please.
    And on a nameserver no less.

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Re: File Open Question
by jerrygarciuh (Curate) on Nov 14, 2001 at 06:18 UTC
    You need to declare all varibles with my when using the strict pragma. So declare @data as my @data
    HTH
    jg
    _____________________________________________________
    My name is Inigo Montoya...
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Re: File Open Question
by Anonymous Monk on Nov 14, 2001 at 06:14 UTC
    i doubt this is the problem.. but you should declare the variable.
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      Oh, declare the @data -- I did that and it's good now. Thanks and sorry about the post.
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Re: File Open Question
by grinder (Bishop) on Nov 14, 2001 at 14:18 UTC

    Note that the idiom of slurping an entire file into an array is a bad habit to get into. It's easy to do, but one day you will slurp a really big file by accident, exhaust all your RAM, start to swap, and bring your system to its knees.

    A much better way to go about reading files is as follows:

    open FILE, $filename or die "$0: cannot open $filename for input: $!\n
+";
# two notes
# 1. Put as much information as possible in the die string
#    as you can lay your hands on.
# 2. That's \n, not /n, but I guess you realised that already...
while( <FILE> ) {
  # possibly...
  chomp;
  # otherwise do what you want with $_
}
close FILE;

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    Creating scripts with small memory footprints is a good idea. Otherwise the other people using the system will start to equate Perl with prolifligate memory consumption, and we don't want Perl to get a bad name, right?

    --
    g r i n d e r
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