Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: q with Perl Regex
Top Forums Shell Programming and Scripting q with Perl Regex Post 302217931 by cbkihong on Thursday 24th of July 2008 12:42:05 AM
Old 07-24-2008
Quote:
Originally Posted by JamesGoh
Now I know that . refers to any single character and the \1 refers to the first character in the line being read (if s/..../.... is being used), but Im still puzzled as to why /(.)\1/ works instead of /[a-zA-Z]+/ for the case of double letters ?
* Incorrect text removed *

/[a-zA-Z]+/ only means matching a contiguous sequence of letters, so not only 'AA' or 'zz' will match, 'Az' will match too.
Last edited by cbkihong; 07-24-2008 at 02:28 AM.. Reason: Incorrect text removed
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Perl REGEX

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)
Discussion started by: evilfreakz
4 Replies

2. Shell Programming and Scripting

Perl regex

I have got numbers like l255677 l376039 l188144 l340482 l440700 l254113 to match the numbers starting with '13' what would be the regex =~/13(.*)/ =======>This is not working .... But for user123,user657 regex =~/user(.*)/ ========>works Thanks for help..!! (7 Replies)
Discussion started by: trina_1
7 Replies

3. Shell Programming and Scripting

Converting perl regex to sed regex

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)
Discussion started by: suntzu
1 Replies

4. UNIX for Dummies Questions & Answers

Perl Regex Help!!!

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)
Discussion started by: manutd
5 Replies

5. Programming

Perl regex

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)
Discussion started by: jhamaks
3 Replies

6. Programming

Perl regex

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)
Discussion started by: ab52
2 Replies

7. Programming

Perl regex

Hello, I'm trying to get a quick help on regex since i'm not a regular programmer. Below is the line i'm trying to apply my regex to..i want to use the regex in a for loop and this line will keep on changing. subject=... (4 Replies)
Discussion started by: jhamaks
4 Replies

8. Shell Programming and Scripting

?= in perl regex

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)
Discussion started by: scriptscript
2 Replies

9. Shell Programming and Scripting

Perl, RegEx - Help me to understand the regex!

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: ^(?!if\b|else\b|while\b|)(?:+?\s+){1,6}(+\s*)\(*\) *?(?:^*;?+){0,10}\{ ------ This is regex to select functions from a C/C++ source and defined in... (2 Replies)
Discussion started by: alex_5161
2 Replies

10. Shell Programming and Scripting

Perl REGEX help

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 CENTOS

perl::critic::policy::builtinfunctions::prohibitstringysplit

Perl::Critic::Policy::BuiltinFunctions::ProhibitStringySUser(Contributed Perl DocumPerl::Critic::Policy::BuiltinFunctions::ProhibitStringySplit(3)

NAME

       Perl::Critic::Policy::BuiltinFunctions::ProhibitStringySplit - Write "split /-/, $string" instead of "split '-', $string".

AFFILIATION

       This Policy is part of the core Perl::Critic distribution.

DESCRIPTION

       The "split" function always interprets the PATTERN argument as a regular expression, even if you specify it as a string.  This causes much
       confusion if the string contains regex metacharacters.  So for clarity, always express the PATTERN argument as a regex.

	   $string = 'Fred|Barney';
	   @names = split '|', $string; #not ok, is ('F', 'r', 'e', 'd', '|', 'B', 'a' ...)
	   @names = split m/[|]/, $string; #ok, is ('Fred', Barney')

       When the PATTERN is a single space the "split" function has special behavior, so Perl::Critic forgives that usage.  See "perldoc -f split"
       for more information.

CONFIGURATION

       This Policy is not configurable except for the standard options.

SEE ALSO

       Perl::Critic::Policy::ControlStrucutres::RequireBlockGrep

       Perl::Critic::Policy::ControlStrucutres::RequireBlockMap

AUTHOR

       Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>

COPYRIGHT

       Copyright (c) 2005-2011 Imaginative Software Systems.  All rights reserved.

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.  The full text of this license
       can be found in the LICENSE file included with this module.

perl v5.16.3							    2014-06-09	   Perl::Critic::Policy::BuiltinFunctions::ProhibitStringySplit(3)
All times are GMT -4. The time now is 02:46 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy