Sponsored Content
Top Forums Shell Programming and Scripting Extract a substring using regular expression Post 302172797 by apraja on Tuesday 4th of March 2008 04:14:08 PM
Old 03-04-2008
Hammer & Screwdriver Extract a substring using regular expression

Hello:

I'm trying to extracta a matching substring from a string using regular expression. I need to extract the date part of any giving string.

All input string will have date in YYYYMMDD format in them, but it can be anywhere in the string.

Eg.

The_Mummy20080125_New
Lost_20071227_In_time
Last20010915Samurai

All I want is to assign the 8 digit date part to a variable.

I tried
$Date_val = echo "The_Mummy20080125_New" | sed "s/._\([[:digit:]]\{8\}\)$/\1/p"

But it does not work. Someone please help me.

Thanks,
Raja
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Regular Expression + Aritmetical Expression

Is it possible to combine a regular expression with a aritmetical expression? For example, taking a 8-numbers caracter sequece and casting each output of a grep, comparing to a constant. THX! (2 Replies)
Discussion started by: Z0mby
2 Replies

2. Linux

Regular expression to extract "y" from "abc/x.y.z" .... i need regular expression

Regular expression to extract "y" from "abc/x.y.z" (2 Replies)
Discussion started by: rag84dec
2 Replies

3. Shell Programming and Scripting

Regular expression Help

Hi What is the meaning of this in regular expression $k =~ s/^\s*//; Plz explain (3 Replies)
Discussion started by: Harikrishna
3 Replies

4. Shell Programming and Scripting

Integer expression expected: with regular expression

CA_RELEASE has a value of 6. I need to check if that this is a numeric value. if not error. source $CA_VERSION_DATA if * ] then echo "CA_RELESE $CA_RELEASE is invalid" exit -1 fi + source /etc/ncgl/ca_version_data ++ CA_PRODUCT_ID=samxts ++ CA_RELEASE=6 ++ CA_WEEK_NO=7 ++... (3 Replies)
Discussion started by: ketkee1985
3 Replies

5. Shell Programming and Scripting

Regular expression to extract ipv6 address

Hi all , I have a string in my weblog xheader v6-day-2011:xx:yy:zz:qq:qq:ww:ee:rr My requirement is to lookup the sting v6-day-2011 in this header and if found would like to extract the V6 ip part . v6-day-2011 is always constant for a ipv6 entry so i would like to extract every thing... (4 Replies)
Discussion started by: jambesh
4 Replies

6. Programming

Perl: How to read from a file, do regular expression and then replace the found regular expression

Hi all, How am I read a file, find the match regular expression and overwrite to the same files. open DESTINATION_FILE, "<tmptravl.dat" or die "tmptravl.dat"; open NEW_DESTINATION_FILE, ">new_tmptravl.dat" or die "new_tmptravl.dat"; while (<DESTINATION_FILE>) { # print... (1 Reply)
Discussion started by: jessy83
1 Replies

7. Programming

How to use regular expression in C/C++ ?

how to code with regexp.h some one can give me instance? thx (4 Replies)
Discussion started by: AKB48
4 Replies

8. Shell Programming and Scripting

regular expression with shell script to extract data out of a text file

hi i am trying to extract some specific data out of a text file using regular expressions with shell script that is using a multiline grep .. and the tool i am using is pcregrep so that i can get compatibility with perl's regular expressions for a sample data like this, i am trying to grab... (6 Replies)
Discussion started by: vemkiran
6 Replies

9. UNIX for Advanced & Expert Users

sed: -e expression #1, char 0: no previous regular expression

Hello All, I'm trying to extract the lines between two consecutive elements of an array from a file. My array looks like: problem_arr=(PRS111 PRS213 PRS234) j=0 while } ] do k=`expr $j + 1` sed -n "/${problem_arr}/,/${problem_arr}/p" problemid.txt ---some operation goes... (11 Replies)
Discussion started by: InduInduIndu
11 Replies

10. Shell Programming and Scripting

Extract regular expression and line below

Hi all, I have a large fasta (dna sequence) file. I would like to extract a portion of the header as well as the sequence (line below the header). Input: Output: All accession values (the term I want to preserve, which is the string including and directly following "GL") are different, but I... (8 Replies)
Discussion started by: pathunkathunk
8 Replies
textutil::trim(n)				    Text and string utilities, macro processing 				 textutil::trim(n)

__________________________________________________________________________________________________________________________________________________

NAME
textutil::trim - Procedures to trim strings SYNOPSIS
package require Tcl 8.2 package require textutil::trim ?0.7? ::textutil::trim::trim string ?regexp? ::textutil::trim::trimleft string ?regexp? ::textutil::trim::trimright string ?regexp? ::textutil::trim::trimPrefix string prefix ::textutil::trim::trimEmptyHeading string _________________________________________________________________ DESCRIPTION
The package textutil::trim provides commands that trim strings using arbitrary regular expressions. The complete set of procedures is described below. ::textutil::trim::trim string ?regexp? Remove in string any leading and trailing substring according to the regular expression regexp and return the result as a new string. This is done for all lines in the string, that is any substring between 2 newline chars, or between the beginning of the string and a newline, or between a newline and the end of the string, or, if the string contain no newline, between the beginning and the end of the string. The regular expression regexp defaults to "[ \t]+". ::textutil::trim::trimleft string ?regexp? Remove in string any leading substring according to the regular expression regexp and return the result as a new string. This apply on any line in the string, that is any substring between 2 newline chars, or between the beginning of the string and a newline, or between a newline and the end of the string, or, if the string contain no newline, between the beginning and the end of the string. The regular expression regexp defaults to "[ \t]+". ::textutil::trim::trimright string ?regexp? Remove in string any trailing substring according to the regular expression regexp and return the result as a new string. This apply on any line in the string, that is any substring between 2 newline chars, or between the beginning of the string and a newline, or between a newline and the end of the string, or, if the string contain no newline, between the beginning and the end of the string. The regular expression regexp defaults to "[ \t]+". ::textutil::trim::trimPrefix string prefix Removes the prefix from the beginning of string and returns the result. The string is left unchanged if it doesn't have prefix at its beginning. ::textutil::trim::trimEmptyHeading string Looks for empty lines (including lines consisting of only whitespace) at the beginning of the string and removes it. The modified string is returned as the result of the command. BUGS, IDEAS, FEEDBACK This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category textutil of the Tcllib SF Trackers [http://sourceforge.net/tracker/?group_id=12883]. Please also report any ideas for enhancements you may have for either package and/or documentation. SEE ALSO
regexp(n), split(n), string(n) KEYWORDS
prefix, regular expression, string, trimming CATEGORY
Text processing textutil 0.7 textutil::trim(n)
All times are GMT -4. The time now is 09:51 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy