use Perl

• grep-foo (Score:2)

  by triv (2745)

  @sizes = grep {length $_ -> [1]} @sizes; Specifically, what is {length $_ -> [1]} doing?

  From the docs:

  Evaluates the BLOCK or EXPR for each element of LIST (locally setting $_ to each element) and returns the list value consist- ing of those elements for which the expression evaluated to true. In scalar context, returns the number of times the expression was true.

  The most basic example is something like:

  perl -e '@foo = grep { $_ } (1,0,undef); print "@foo\n"'

  This goes though the list (1,

  --
  
  --
  "Cake or Death!" .... "Cake please"
  • Re:grep-foo (Score:1)

    by xenchu (4746)

    Oh. Ow. Ouch! @size is not an array of file names but rather a line with file name, file size, etc. I might plead that I am a windows programmer but geez, even so, I should have realized that. My stumbling block was [1]. I couldn't see the relationship even knowing what -> was. Density^3. Thank you.
• where's the rest of the code? (Score:1)

  by cog (4665)

  I'm curious about the rest of the code. What happened to @sizes before that? Where can I see that?
  • Re:where's the rest of the code? (Score:1)

    by xenchu (4746)

    Certainly. This was written by Abigail-II in answer the question Finding Top 10 Largest Files on PerlMonks. Since Abigail-II wrote it I have no doubt as to the correctness of the program:

    #!/usr/bin/perl
    
    use strict;
    use warnings;
    no warnings qw /syntax/;
    
    open my $fh => "find / -type f |" or die;
    
    my @sizes = map {[-1 => ""]} 1 .. 10;
    
    while (<$fh>) {
        chomp;
        my $size = -s;
        next if $size < $sizes [-1] [0];
        foreach my $i (0 .. $#sizes) {
     
    • Re:where's the rest of the code? (Score:3, Informative)

      by bart (450)

      The idea is to remove the empty entries, in case there are fewer than 10 real entries.