I am not a big expert in regex and have just little understanding of that language.
Could you help me to understand the regular Perl expression:
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This is regex to select functions from a C/C++ source and defined in UltraEdit (if interested where it is from)
It works.
I able to use it in my perl script by applying 'm' - multyline regex and having whole file as one string (by 'undef $/')
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I am going to show here my understanding how much I have and will ask where I do not know what is happening.
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Please, correct me, if I am wrong in any assumption and give me an idea where I do not have any!
Thanks!
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So, as I understanding this regex so far, is:
Thanks!
Last edited by alex_5161; 06-12-2015 at 01:38 PM..
For a programming exercise, I am mean to design a Perl script that detects double letters in a text file.
I tried the following expressions
# Check for any double letter within the alphabet
/+/
# Check for any repetition of an alphanumeric character
/\w+/
Im aware that the... (8 Replies)
Hi,
Can anyone help me to find regular expression for the following in Perl?
"The string can only contain lower case letters (a-z) and no more than one of any letter."
For example: "table" is accepted, whether "dude" is not.
I have coded like this:
$str = "table";
if ($str =~ m/\b()\b/) {... (4 Replies)
The following regular expression is found in a book I have been reading. It apparently can be used on an /etc/passwd file to find any accounts which have no password. I am having a heck of a time seeing how it works, and I was wondering if someone could run me through it. I will take a stab at... (1 Reply)
I am having trouble parsing rpm filenames in a shell script.. I found a snippet of perl code that will perform the task but I really don't have time to rewrite the entire script in perl. I cannot for the life of me convert this code into something sed-friendly:
if ($rpm =~ /(*)-(*)-(*)\.(.*)/)... (1 Reply)
Hi,
I get the following when I cat a file *.log
xxxxx
=====
dasdas gwdgsg fdsagfsag agsdfag
=====
random data
=====
My output should look like :
If the random data after the 2nd ==== is null then OK should be printed else
the random data should be printed.
How do I go about this... (5 Replies)
HI,
I'm new to perl and need simple regex for reading a file using my perl script.
The text file reads as -
filename=/pot/uio/current/myremificates.txt
certificates=/pot/uio/current/userdir/conf/user/gamma/settings/security/... (3 Replies)
Hi Guys
I have the following regex
$OSRELEASE = $1 if ($output =~ /(Mac OS X (Server )?10.\d)/);
output is currently
Mac OS X 10.7.5
when the introduction of Mac 10.8 output changes to
OS X 10.8.2
they have dropped the Mac bit so i changed the regex to be (2 Replies)
Could anyone please make me understand how the ?= works below ..
After executing this I am getting the same output.
$string="I love chocolate.";
$string =~ s/chocolate(?= ice)/vanilla/;
print "$string\n"; (2 Replies)
I'm trying to get some exclusions into our sendmail regular expression for the K command. The following configuration & regex works:
LOCAL_CONFIG
#
Kcheckaddress regex -a@MATCH
+<@+?\.++?\.(us|info|to|br|bid|cn|ru)
LOCAL_RULESETS
SLocal_check_mail
# check address against various regex... (0 Replies)
Experts -
I found a script on one of the servers that I work on and I need help understanding
one of the lines.
I know what the script does, but I'm having a hard time understanding the grouping.
Can someone help me with this?
Here's the script...
#!/usr/bin/perl
use strict;
use... (2 Replies)
Discussion started by: timj123
2 Replies
LEARN ABOUT DEBIAN
graphviz::regex
GraphViz::Regex(3pm) User Contributed Perl Documentation GraphViz::Regex(3pm)NAME
GraphViz::Regex - Visualise a regular expression
SYNOPSIS
use GraphViz::Regex;
my $regex = '(([abcd0-9])|(foo))';
my $graph = GraphViz::Regex->new($regex);
print $graph->as_png;
DESCRIPTION
This module attempts to visualise a Perl regular expression. Understanding regular expressions is tricky at the best of times, and regexess
almost always evolve in ways unforseen at the start. This module aims to visualise a regex as a graph in order to make the structure clear
and aid in understanding the regex.
The graph visualises how the Perl regular expression engine attempts to match the regex. Simple text matches or character classes are
represented by.box-shaped nodes. Alternations are represented by a diamond-shaped node which points to the alternations. Repetitions are
represented by self-edges with a label of the repetition type (the nodes being repeated are pointed to be a full edge, a dotted edge points
to what to match after the repetition). Matched patterns (such as $1, $2, etc.) are represented by a 'START $1' .. 'END $1' node pair.
This uses the GraphViz module to draw the graph.
METHODS
new
This is the constructor. It takes one mandatory argument, which is a string of the regular expression to be visualised. A GraphViz object
is returned.
my $graph = GraphViz::Regex->new($regex);
as_*
The regex can be visualised in a number of different graphical formats. Methods include as_ps, as_hpgl, as_pcl, as_mif, as_pic, as_gd,
as_gd2, as_gif, as_jpeg, as_png, as_wbmp, as_ismap, as_imap, as_vrml, as_vtx, as_mp, as_fig, as_svg. See the GraphViz documentation for
more information. The two most common methods are:
# Print out a PNG-format file
print $g->as_png;
# Print out a PostScript-format file
print $g->as_ps;
BUGS
Note that this module relies on debugging information provided by Perl, and is known to fail on at least two versions of Perl: 5.005_03 and
5.7.1. Sorry about that - please use a more recent version of Perl if you want to use this module.
AUTHOR
Leon Brocard <acme@astray.com>
COPYRIGHT
Copyright (C) 2000-1, Leon Brocard
This module is free software; you can redistribute it or modify it under the same terms as Perl itself.
perl v5.14.2 2012-04-02 GraphViz::Regex(3pm)