while following perl hack book

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

While folloing perl hack book's example(chap 1 hack 5; it's about auto completion in vim and putting all modules in one file to search from), I found it very surprising that it wasn't working on my linux box
I am sure it was working somewhere else and I overlooked something, I digged in and see if I could make it work on my box

Finally results being at the bottom, and looking at the file that I created after running the script looks like it's working
Can some more experienced monks fix it so that I can see what I should have done instead of what I did?
My maine question is, when encountered below

            ## Need to get rid of directories, such as 5.8.8 or i386-l
+inux-thread-multi
            ## 5.8.8::URI.pm
            ## i386-linux-thread-multi::Net::DNS::RR::MG.pm
            $file =~ s{^ +\d+\.\d+\.\d+::}{}g;
            $file =~ s{^ ?[^A-Z]+::}{}g;
            $file =~ s/^ +//g;
[download]

Looks like I could have gotten rid of directories more simpler way then applying 3 regex back to back to back?

use File::Find 'find';

# Where to create this list...
my $LIST_DIR  = "$ENV{HOME}/.vim_extras/"
my $LIST_FILE = "file_that_lists_every_installed_Perl_module";

# Make sure the directory is available...
unless (-e $LIST_DIR )
{
    mkdir $LIST_DIR
        or die "Couldn't create directory $LIST_DIR ($!)\\n";
}

# (Re)create the file...
open my $fh, '>', "$LIST_DIR$LIST_FILE"
    or die "Couldn't create file '$LIST_FILE' ($!)\\n";

# Only report each module once (the first time it's seen)...
my %already_seen;

# Walk through the module include directories, finding .pm files...
for my $incl_dir (@INC)
{
    find
    {
        wanted => sub
        {
            my $file = $_;

            # They have to end in .pm...
            return unless $file =~ /\\.pm\\z/;

            # Convert the path name to a module name...
            $file =~ s{^\\Q$incl_dir/\\E}{ };
            $file =~ s{/}{::}g;
            $file =~ s{\\.pm\\z}{ };

            # Handle standard subdirectories (like site_perl/ or 5.8.6
+/)...
            $file =~ s{^.*\\b[a-z_0-9]+::}{ };
            $file =~ s{^\\d+\\.\\d+\\.\\d+::(?:[a-z_][a-z_0-9]*::)?}{ 
+};
            return if $file =~ m{^::};

            # Print the module's name (once)...
            print {$fh} $file, "\\n" unless $already_seen{$file}++;
        },
        no_chdir => 1,
    }, $incl_dir;
}
[download]

so I changed to below and works but how I did it looks very inefficient..

for my $incl_dir (@INC)
{
    find
    {
        wanted => sub
        {
            my $file = $_;

            # They have to end in .pm...
            return unless $file =~ /.+\.pm/;
            # Convert the path name to a module name...
            $file =~ s{^\Q$incl_dir/\E}{ };
            $file =~ s{/}{::}g;

            # Handle standard subdirectories (like site_perl/ or 5.8.6
+/)...
            ## 5.8.8::URI.pm
            ## i386-linux-thread-multi::Net::DNS::RR::MG.pm
            $file =~ s{^ +\d+\.\d+\.\d+::}{}g;
            $file =~ s{^ ?[^A-Z]+::}{}g;
            $file =~ s/^ +//g;
            return if $file =~ m{^::};

            # Print the module's name (once)...
            #print "printing\n";
            print {$fh} $file, "\n" unless $already_seen{$file}++;
        },
        no_chdir => 1,
    }, $incl_dir;
[download]

Comment on while following perl hack book Select or Download Code

Replies are listed 'Best First'.
Re: while following perl hack book by Util (Priest) on Feb 04, 2008 at 04:28 UTC
The problem with the original, as you posted it, is that all the backslashes have been doubled. Change all occurances of '`\\`' into '`\`', and it works fine. The downloadable code from O'Reilly does not have the doubled backslashes, (and neither does the copy of the page at Google Books), but it is missing a trailing semi-colon from the `$LIST_DIR` line. In the tarball, the path is `perl_hacks_examples/productivity_hacks/autocomplete_perl_identifiers_in_vim/find_pm_files.pl`.	[reply] [d/l] [select]
Re^2: while following perl hack book by convenientstore (Pilgrim) on Feb 04, 2008 at 04:35 UTC
hey thanks! didn't realize they have downloadable codes. Downloaded them and will be going over them. I still am however looking for ways to optimize that code (but I am sure point of that book wasn't about optimizing UPDATE: can someone please explain to me what wanted=> sub is all about? I thought wanted() was a simple sub? so I am not sure what wanted=> sub is doing in the code `{ find { wanted => sub { ## code.... }, no_chdir => 1, }, $incl_dir; }` [download]	[reply] [d/l]
Re^3: while following perl hack book by ysth (Canon) on Feb 04, 2008 at 08:59 UTC
sub { some code } generates an anonymous subroutine and returns a reference to it. So: `find( { wanted => sub { blah blah } }, @dirs );` [download] is the same as `sub foo { blah blah } find( { wanted => \&foo }, @dirs );` [download] but without declaring a separate, named subroutine. Update: fixed to pass hashref and array -- Online Fortune Cookie Search	[reply] [d/l] [select]
Re^4: while following perl hack book by convenientstore (Pilgrim) on Feb 04, 2008 at 20:04 UTC
Re^5: while following perl hack book by ysth (Canon) on Feb 04, 2008 at 20:11 UTC
Re^5: while following perl hack book by Util (Priest) on Feb 05, 2008 at 02:45 UTC
Some notes below your chosen depth have not been shown here
Re^3: while following perl hack book by Util (Priest) on Feb 05, 2008 at 02:33 UTC
++ysth is correct about named vs anonymous subroutines. Another confusing issue is that the first argument to find() can be either a code reference or a hash reference. In the simpler case, where you have no special options to set, you just make the first argument a code reference; a reference to the "callback" sub. The sub is always named "wanted" in the documentation, but it can have any name, or be a anonymous sub. `find( \&some_subroutine, @directories_to_search, );` [download] If you need to set a special option in find(), like 'no_chdir', then you pass a hash reference as the first argument. The code reference (that you would have used as the first argument in the simpler case) becomes the 'wanted' option. `find( { wanted => \&some_subroutine, other_option => 'other_option_value', # ... }, @directories_to_search, );` [download]	[reply] [d/l] [select]


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