Beefy Boxes and Bandwidth Generously Provided by pair Networks
Welcome to the Monastery
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??

I have been using this regular expression to parse *nix paths as part of a module.

my $rxParsePath = qr {(?x) # Use extended regular expression syntax to # allow comments and white space ^ # Anchor pattern to beginning of string (?=.) # Zero-width look ahead assertion to ensure # that there must be at least one character # for the match to succeed (.*/)? # A memory grouping (1st) for path, greedy # match of any characters up to and including # the rightmost slash (the path part) with a # quantifier of '?' (0 or 1), i.e. there # may or may not be a directory part ( # Open memory grouping (2nd) for file name (.*?) # A memory grouping (3rd) for file name stub # of a non-greedy match of any character # without a quantifier since, if there is a # file name part, at least some of it will # form a stub otherwise it would be a dot-file ( # A memory grouping (4th) for file name # extension (?<=[^/]) # zero width look behind assertion such # that following pattern will only succeed # if preceded by any caracter other than # a slash '/' \.[^.]+ # a literal dot '.' followed by one or more # non-dots )? # Close memory grouping (4th) with a quantifier # of '?' (0 or 1), i.e. there may or may not # be a file name extension part )? # Close memory grouping (2nd) with a quantifier # of '?' (0 or 1), i.e. there may or may not # be a file name part $ # Anchor pattern to end of string };

Here is a short script using it, without extended syntax for brevity, to pull out the elements of a *nix path.

use strict; use warnings; my $rxParsePath = qr{^(?=.)(.*/)?((.*?)((?<=[^/])\.[^.]+)?)?$}; print <<EOT; Path Directory File Name File Stub Extension EOT print map { sprintf qq{%20s%15s%15s%10s%10s\n}, @$_ } map { [ $_, map { defined $_ ? $_ : q{} } m{$rxParsePath} ] } qw { /etc/motd /var/adm/messages.1 .alias a.html ab.cd.txt /bin };

The results

Path Directory File Name File Stub Extension /etc/motd /etc/ motd motd /var/adm/messages.1 /var/adm/ messages.1 messages .1 .alias .alias .alias a.html a.html a .html ab.cd.txt ab.cd.txt ab.cd .txt /bin / bin bin

I hope this will be useful.

Cheers,

JohnGG

Update: Corrected superfluous text from C&P error.


In reply to Re: Regex To Remove File Extension by johngg
in thread Regex To Remove File Extension by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others pondering the Monastery: (14)
    As of 2015-07-06 18:40 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









      Results (80 votes), past polls