Help with regular expressions


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Help with regular expressions
# 8  
Old 08-10-2010
Quote:
Originally Posted by pxalpine
Thanks agama. Just to learn, what does the /p at the end of the code do?
Hi.

it means print whatever expression is matched (in this case). You need it because you're using the -n option (which means don't print anything). Without it, you wouldn't get any output.
This User Gave Thanks to Scott For This Post:
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Regular expressions

I need to pick a part of string lets stay started with specific character and end with specific character to replace using sed command the line is like this:my audio book 71-skhdfon1dufgjhgf8.wav' I want to move the characters beginning with - end before. I have different files with random... (2 Replies)
Discussion started by: XP_2600
2 Replies

2. Shell Programming and Scripting

Regular Expressions

I am new to shell scripts.Can u please help me on this req. test_user = "Arun" if echo "test_user is a word" else echo "test_user is not a word" (1 Reply)
Discussion started by: chandrababu
1 Replies

3. Shell Programming and Scripting

Regular Expressions

#!/usr/bin/perl $word = "one last challenge"; if ( $word =~ /^(\w+).*\s(\w+)$/ ) { print "$1"; print "\n"; print "$2"; } The output shows that "$1" is with result one and "$2" is with result challenge. I am confused about how this pattern match expression works step by step. I... (8 Replies)
Discussion started by: DavidHe
8 Replies

4. UNIX for Dummies Questions & Answers

Regular expressions

In regular expressions with grep(or egrep), ^ works if we want something in starting of line..but what if we write ^^^ or ^ for pattern matching??..Hope u all r familiar with regular expressions for pattern matching.. (1 Reply)
Discussion started by: aadi_uni
1 Replies

5. UNIX for Advanced & Expert Users

Regular Expressions

Hi, below is a piece of code written by my predecessor at work. I'm kind of a newbie and am trying to figure out all the regular expressions in this piece of code. It is really a tough time for me to figure out all the regular expressions. Please shed some light on the regular expressions... (3 Replies)
Discussion started by: ramky79
3 Replies

6. Shell Programming and Scripting

regular expressions

Hello, Let say I have a string with content "Free 100%". How can extract only "100" using ksh? I would this machanism to work if instead of "100" there is any kind of combination of numbers(ex. "32", "1238", "1"). I want to get only the digits. I have written something like this: ... (4 Replies)
Discussion started by: whatever
4 Replies

7. UNIX for Dummies Questions & Answers

regular expressions

Hi Gurus, I need help with regular expressions. I want to create a regular expression which will take only alpha-numeric characters for 7 characters long and will throw out an error if longer than that. i tried various combinations but couldn't get it, please help me how to get it guys. ... (2 Replies)
Discussion started by: ragha81
2 Replies

8. Shell Programming and Scripting

Help with regular expressions

I have following content in the file CancelPolicyMultiLingual3=U|PC3|EN RestaurantInfoCode1=U|restID1|1 ..... I am trying to use following matching extression \|(+) to get this PC3|EN restID1|1 Obviously it does not work. Any ideas? (13 Replies)
Discussion started by: arushunter
13 Replies

9. Shell Programming and Scripting

regular expressions

Hi, can anyone advise me how to shorten this: if || ; then I tried but it dosent seem to work, whats the correct way. Cheers (4 Replies)
Discussion started by: jack1981
4 Replies

10. Programming

regular expressions in c++

How do I use the regular expressions in c++? (2 Replies)
Discussion started by: szzz
2 Replies
Login or Register to Ask a Question
Char(3) 						User Contributed Perl Documentation						   Char(3)

NAME
PDL::Char -- PDL subclass which allows reading and writing of fixed-length character strings as byte PDLs SYNOPSIS
use PDL; use PDL::Char; my $pchar = PDL::Char->new( [['abc', 'def', 'ghi'],['jkl', 'mno', 'pqr']] ); $pchar->setstr(1,0,'foo'); print $pchar; # 'string' bound to "", perl stringify function # Prints: # [ # ['abc' 'foo' 'ghi'] # ['jkl' 'mno' 'pqr'] # ] print $pchar->atstr(2,0); # Prints: # ghi DESCRIPTION
This subclass of PDL allows one to manipulate PDLs of 'byte' type as if they were made of fixed length strings, not just numbers. This type of behavior is useful when you want to work with charactar grids. The indexing is done on a string level and not a character level for the 'setstr' and 'atstr' commands. This module is in particular useful for writing NetCDF files that include character data using the PDL::NetCDF module. FUNCTIONS
new Function to create a byte PDL from a string, list of strings, list of list of strings, etc. # create a new PDL::Char from a perl array of strings $strpdl = PDL::Char->new( ['abc', 'def', 'ghij'] ); # Convert a PDL of type 'byte' to a PDL::Char $strpdl1 = PDL::Char->new (sequence (byte, 4, 5)+99); $pdlchar3d = PDL::Char->new([['abc','def','ghi'],['jkl', 'mno', 'pqr']]); string Function to print a character PDL (created by 'char') in a pretty format. $char = PDL::Char->new( [['abc', 'def', 'ghi'], ['jkl', 'mno', 'pqr']] ); print $char; # 'string' bound to "", perl stringify function # Prints: # [ # ['abc' 'def' 'ghi'] # ['jkl' 'mno' 'pqr'] # ] # 'string' is overloaded to the "" operator, so: # print $char; # should have the same effect. setstr Function to set one string value in a character PDL. The input position is the position of the string, not a character in the string. The first dimension is assumed to be the length of the string. The input string will be null-padded if the string is shorter than the first dimension of the PDL. It will be truncated if it is longer. $char = PDL::Char->new( [['abc', 'def', 'ghi'], ['jkl', 'mno', 'pqr']] ); $char->setstr(0,1, 'foobar'); print $char; # 'string' bound to "", perl stringify function # Prints: # [ # ['abc' 'def' 'ghi'] # ['foo' 'mno' 'pqr'] # ] $char->setstr(2,1, 'f'); print $char; # 'string' bound to "", perl stringify function # Prints: # [ # ['abc' 'def' 'ghi'] # ['foo' 'mno' 'f'] -> note that this 'f' is stored "f" # ] atstr Function to fetch one string value from a PDL::Char type PDL, given a position within the PDL. The input position of the string, not a character in the string. The length of the input string is the implied first dimension. $char = PDL::Char->new( [['abc', 'def', 'ghi'], ['jkl', 'mno', 'pqr']] ); print $char->atstr(0,1); # Prints: # jkl perl v5.12.1 2009-10-17 Char(3)