Sponsored Content
Full Discussion: Understanding sed
Top Forums Shell Programming and Scripting Understanding sed Post 302774017 by panyam on Friday 1st of March 2013 04:16:52 AM
Old 03-01-2013
Hi Scrutinizer,

Thanks for the reply. I got your second correctly.

Your first answer is slightly confusing me!..

Let's say the sample input is:

Code:
abcd:x:panyam:panyam:Panyam:512

echo "abcd:x:panyam:panyam:Panyam:512" | sed 's/^\([^:]*\):[^:]:/\1::/' gives me:

abcd::panyam:panyam:Panyam:512

\([^:]*\) matches : abcd
[^:] matches :x

\1 : prints only "abcd"..

Now, how the rest of the line is coming in output as it is? I mean
Code:
"panyam:panyam:Panyam:512"

.

Is it because sed prints the non matching patterns as it is?

Is my understanding correct?
 

9 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

need further understanding of init.d

I needt o know how what init.d does and how it knows which dameons/applications to turn off and how to restart the applications after reboot. any OS - solaris/hp-ux (1 Reply)
Discussion started by: jigarlakhani
1 Replies

2. Shell Programming and Scripting

understanding the sed command

Guys, I am trying to understand the sed command here. adx001 $ a=/clocal/dctrdata/user/dctrdat1/trdroot/recouncil adx001 $ b=`echo $a | sed 's/\//\\\\\//g'` adx001 $ echo $b \/clocal\/dctrdata\/user\/dctrdat1\/trdroot\/recouncil The sed command i took it from the script. Please... (3 Replies)
Discussion started by: mac4rfree
3 Replies

3. UNIX for Dummies Questions & Answers

Help understanding sed

I am trying to create a basic script that converts an Oracle script into a Sybase script. The only things im changing are Datatypes and the to_char and to_date functions. I am not really 100% sure of the way it works. I have tried running the functions through a loop to replace each word line... (6 Replies)
Discussion started by: Makaer
6 Replies

4. Shell Programming and Scripting

need help understanding mv

I just started shell coding and I'm a bit confused on how 'mv' works can someone explain to me how it works and if i did this correctly. Thanks. echo "Enter Name of the first file:" read file1 #echo $file1 if ; then echo "Sorry, file does not exist." exit 1 ... (16 Replies)
Discussion started by: taiL
16 Replies

5. UNIX for Dummies Questions & Answers

understanding {%/*}/

Hi Gurus: I am trying to understand the following line of code.I did enough of googling to understand but no luck.Please help me understand the follow chunk of code: X=$0 MOD=${X%/*}/env.ksh X is the current script from which I am trying to execute. Say if X=test.ksh $MOD is echoing :... (3 Replies)
Discussion started by: vemana
3 Replies

6. UNIX for Dummies Questions & Answers

understanding sed command

Hi Friends, I need a small help in understanding the below sed command. $ cat t4.txt 1 root 1 58 0 888K 368K sleep 4:06 0.00% init 1 root 1 58 0 888K 368K sleep 4:06 0.00% init last $ sed 's/*$//' t4.txt 1 root 1 58 0 888K ... (3 Replies)
Discussion started by: forroughuse
3 Replies

7. Shell Programming and Scripting

help understanding regex with grep & sed

I have the following line of code that works wonders. I just don't completely understand it as I am just starting to learn regex. Can you help me understand exactly what is happening here? find . -type f | grep -v '^\.$' | sed 's!\.\/!!' (4 Replies)
Discussion started by: trogdortheburni
4 Replies

8. Shell Programming and Scripting

Need your help in understanding this

Hi, I found this in a script and I would like to know how this works Code is here: # var1=PART1_PART2 # var2=${var1##*_} # echo $var2 PART2 I'm wondering how ##* makes the Shell to understand to pick up the last value from the given. (2 Replies)
Discussion started by: sathyaonnuix
2 Replies

9. Shell Programming and Scripting

Need Quick help on Understanding sed Regex

Hi Guys, Could you please kindly explain what exactly the below SED command will do ? I am quite confused and i assumed that, sed 's/*$/ /' 1. It will remove tab and extra spaces .. with single space. The issue is if it is removing tab then it should be Î right .. please assist.... (3 Replies)
Discussion started by: Nandy
3 Replies
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)
All times are GMT -4. The time now is 09:42 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy