Re: undefined hash elements

[Random_Walk]

On my current OS, Linux Mint, the following code works. Note I take the headers from the first line of df and use them. I then have a small abstraction of a name hash to map mount and percent to appropriate fields. I think your list of headers came from another OS than the one you are running on, and that is leading down the wrong path.

#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

# a couple of headers that vary from df to df
my %name = (
    percent => 'Use%',
    mount   => 'Mounted',
);

# my @headers = qw(name size used free capacity mount);
my @df = `df -k`;
my @headers = split /\s+/, shift @df;

my %devices;
for my $line (@df) {
    print $line;
    my %info;
    @info{@headers} = split /\s+/, $line;  # note the hash slice
    $info{capacity} = _percentage_to_decimal($info{$name{percent}});
    $devices{ $info{$name{mount}} } = \%info;
}

# Change 12.3% to .123
sub _percentage_to_decimal {
    my $percentage = shift;
    $percentage =~ s{%}{};
    return $percentage / 100;
}
print Dumper \%devices;

Cheers,
R.

[MrTEE]

Yeah It works for me at home as well. the DF has long values at work, they get kicked to another line. That is just what DF does. . The df -k | grep -v var cleans up - but i have gotten these undefined errors before. it is a linux box.

[capsper@casperbox .wjohnson]$ uname -a
Linux casper25s 2.6.18-194.32.1.el5 #1 SMP Wed Jan 5 17:52:25 EST 2011
+ x86_64 x86_64 x86_64 GNU/Linux

This is the data dumper - is there a way to get rid of the undef's ?

 
[icapsper@casperbox .wjohnson]$ ./get_df.just_capacity
$VAR1 = {};
Use of uninitialized value in substitution (s///) at ./get_df.just_cap
+acity line 25.
Use of uninitialized value in division (/) at ./get_df.just_capacity l
+ine 26.
Use of uninitialized value in hash element at ./get_df.just_capacity l
+ine 18.
$VAR1 = {
          '' => {
                  'free' => undef,
                  'mount' => undef,
                  'used' => undef,
                  'name' => '/dev/mapper/VolGroup00-LogVol00',
                  'capacity' => '0',
                  'size' => undef
                }
        };

[MrTEE]

I dump out the %info and %devices hashes

use Data::Dumper ;
my %devices;
for my $line (@df) {
    use Data::Dumper ;
    my %info;
    print Dumper (\%info);
    @info{@headers} = split /\s+/, $line;  # note the hash slice
    $info{capacity} = _percentage_to_decimal($info{capacity});
    $devices{ $info{mount} } = \%info;
    print Dumper(\%devices);
}