in reply to Re^3: Data manipulation on a file
in thread Data manipulation on a file

Thanks for the replies, I am just about there with what I am needing. The print comes out nicely to STD out however I am a little confused as to how I assign the output to a scalar $output = . In the for loop what syntax is needed to assign the result to a variable concatinating each time. Once the loop of the hash is assigned to a $output then I can take it from there. Many thanks and sorry for the silly quesitons 

#!/usr/bin/perl
use strict;
use warnings;

my $filer;
my %filer_hash;

for (qx(mount -t nfs | awk -F/ '{print \$1,\$3}' | sed -r 's/(blah.*:)
+|(bblah.*:)//g' |sort)) {
    chomp;
    my ($host, $mp) = split;
    push @{ $filer_hash{$host} }, $mp;
}
foreach $filer ( sort { ${filer_hash{$b}} <=> ${filer_hash{$a}} } keys
+ %filer_hash ) {
   print "$filer:@{$filer_hash{$filer}},"
}

[download]

Replies are listed 'Best First'.
Re^5: Data manipulation on a file
by Corion (Patriarch) on Oct 01, 2015 at 09:34 UTC

    Instead of printing it, append it to a variable:

    my $output = '';
for ( ... ) {
    $output .= "$file:$@$filer_hash{$filer}},";
}
print "Now have: $output\n";

    [download]
[reply]
[d/l]

      Wow another great bit of help, maybe one day I will get to grips with perl. For just now I thank you once again it all works great now. ta

[reply]
Re^5: Data manipulation on a file
by sstruthe (Novice) on Oct 02, 2015 at 20:50 UTC

    Small problem now that the output when run on a large amount of linux hosts is producing duplicate mount points for different shares etc. This is due to the many mounts on the same mountpoint.

    like this $ouputstring: host1: mountpoint1 mountpoint1 mountpoint1 mountpoint2 host25: mountpoint5 mountpoint5 mounpoint5 mountpoint6 m......78.

    it would be really nice to remove the duplicates but this would mean logic before updating the array elements or logic coming out of the dump. As I am just dumping the full hash into a $scalar this could get tricky. Anyone got any suggestions on removing the duplicate mount points once the hash has been dumped to the scalar or should I put logic in the dump or even into the push. Perl is so powerfully but still a newbie here so any help appreciated. Many thanks 
    
#!/usr/bin/perl
use strict;
use warnings;

my $filer;
my %filer_hash;

for (qx(mount -t nfs | awk -F/ '{print \$1,\$3}' | sed -r 's/(blah.*:)
+|(bblah.*:)//g' |sort)) {
    chomp;
    my ($host, $mp) = split;
    push @{ $filer_hash{$host} }, $mp;
}
foreach $filer ( sort { ${filer_hash{$b}} <=> ${filer_hash{$a}} } keys
+ %filer_hash ) {
   $outputstring .= "$filer:@{$filer_hash{$filer}},"
}
print "  This is my output : $outputstring

    [download]
[reply]
[d/l]
      Have a look at the uniq and distinct functions from List::MoreUtils.

      For example:

      use Modern::Perl qw/2015/;
use List::MoreUtils qw/uniq/;
my @mountpoints = qw/one two three three two four one one five six/;

print join ' ', uniq sort @mountpoints;

      [download]

      Output: five four one six three two

      CountZero

      A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James

      My blog: Imperial Deltronics
[reply]
[d/l]
[select]

        Thanks this looks really cool and straight forward. Should I just run this on the output string that has been dumped from the hash of arrays. wow you guys are great, perl is getting cool

[reply]

      Thanks for the wisdom, however unfortunately if I use a module I would have to make sure that module was installed on every host that I want to use this on. Sadly that itself is a huge problem. It really has to be code from core perl I do not have the luxury of most of the CPAN modules. Unless of course "uniq" and "distinct" come with core perl. Any ideas are most welcome

[reply]

In Section Seekers of Perl Wisdom