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Top Forums UNIX for Dummies Questions & Answers | help | unix | grep (GNU grep) 2.5.1 | advanced regex syntax Post 302361614 by MykC on Tuesday 13th of October 2009 04:31:29 PM
Old 10-13-2009
| help | unix | grep (GNU grep) 2.5.1 | advanced regex syntax

Hello,

I'm working on unix with grep (GNU grep) 2.5.1. I'm going through some of the newer regex syntax using Regular Expression Reference - Advanced Syntax a guide.

Code:
ls -aLl /bin | grep "\(x\)"

Which works, just highlights 'x' where ever, when ever.

I'm trying to to get (?:) to work but I just get no return.

Code:
 ls -aLl /bin | grep "\(\?\:x\)"

Code:
 ls -aLl /bin | grep "\(\?:x\)"

Code:
 ls -aLl /bin | grep "\(?\:x\)"

All of these return nothing. I'm not sure what I need to do to implement this. Like GNU grep supports the advance features like look ahead/behind, conditionals, backreference, etc?

The below code works which using grouping:
Code:
ls -aLl /bin | grep "^\([^x]*x\)\{1\}[^x]*$"

 

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Locale::Codes::LangFam(3pm)				 Perl Programmers Reference Guide			       Locale::Codes::LangFam(3pm)

NAME
Locale::Codes::LangFam - standard codes for language extension identification SYNOPSIS
use Locale::Codes::LangFam; $lext = code2langfam('apa'); # $lext gets 'Apache languages' $code = langfam2code('Apache languages'); # $code gets 'apa' @codes = all_langfam_codes(); @names = all_langfam_names(); DESCRIPTION
The "Locale::Codes::LangFam" module provides access to standard codes used for identifying language families, such as those as defined in ISO 639-5. Most of the routines take an optional additional argument which specifies the code set to use. If not specified, the default ISO 639-5 language family codes will be used. SUPPORTED CODE SETS
There are several different code sets you can use for identifying language families. A code set may be specified using either a name, or a constant that is automatically exported by this module. For example, the two are equivalent: $lext = code2langfam('apa','alpha'); $lext = code2langfam('apa',LOCALE_LANGFAM_ALPHA); The codesets currently supported are: alpha This is the set of three-letter (lowercase) codes from ISO 639-5 such as 'apa' for Apache languages. This is the default code set. ROUTINES
code2langfam ( CODE [,CODESET] ) langfam2code ( NAME [,CODESET] ) langfam_code2code ( CODE ,CODESET ,CODESET2 ) all_langfam_codes ( [CODESET] ) all_langfam_names ( [CODESET] ) Locale::Codes::LangFam::rename_langfam ( CODE ,NEW_NAME [,CODESET] ) Locale::Codes::LangFam::add_langfam ( CODE ,NAME [,CODESET] ) Locale::Codes::LangFam::delete_langfam ( CODE [,CODESET] ) Locale::Codes::LangFam::add_langfam_alias ( NAME ,NEW_NAME ) Locale::Codes::LangFam::delete_langfam_alias ( NAME ) Locale::Codes::LangFam::rename_langfam_code ( CODE ,NEW_CODE [,CODESET] ) Locale::Codes::LangFam::add_langfam_code_alias ( CODE ,NEW_CODE [,CODESET] ) Locale::Codes::LangFam::delete_langfam_code_alias ( CODE [,CODESET] ) These routines are all documented in the Locale::Codes::API man page. SEE ALSO
Locale::Codes The Locale-Codes distribution. Locale::Codes::API The list of functions supported by this module. http://www.loc.gov/standards/iso639-5/id.php ISO 639-5 . AUTHOR
See Locale::Codes for full author history. Currently maintained by Sullivan Beck (sbeck@cpan.org). COPYRIGHT
Copyright (c) 2011-2013 Sullivan Beck This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. perl v5.18.2 2013-11-04 Locale::Codes::LangFam(3pm)
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