I am using Perl version 5.8.4 and trying to understand the use of regular expression. Following is my code and output.
Output:-
First Word (using \A): Perl
Line Starts (using ^): Perl Scripting
I know
* (star) is used to 'Matches 0 or more occurrence of preceding expression'.
? (question mark) is used to 'Matches 0 or 1 occurrence of preceding expression'.
But I did not understand how both (*?) are working together in above piece of code.
i can only find the first occurance of a pattern how do i set it to loop untill all occurances have changed.
#! /usr/bin/perl
use POSIX;
open (DFH_FILE, "./dfh") or die "Can not read file ($!)";
foreach (<DFH_FILE>) {
if ($_ !~ /^#|^$/) {
chomp;
... (1 Reply)
hi i am trying to get digits inside brackes from file , whose structure is defined below
CREATE TABLE TELM
(SOC_NO CHAR (3) NOT NULL,
TXN_AMOUNT NUMBER (17,3)
SIGN_ON_TIME CHAR (8)
TELLER_APP_LIMIT NUMBER (17,3)
FIL01 ... (2 Replies)
Hello
I got the below one from in one of this forums
For Ex: Loading File System Networking in nature
now i need to extract the patterns between the words File and Networking :
i.e. sample output: System
cmd used : cat <file> | sed 's/.*File //' | sed 's/Closing.*$//'
Actually... (0 Replies)
Hi,
I got doubt in Pattern matching, could you tell me how the following differs in action ??
if ( $line1==/$line2/ )
if ( $line1=~/$line2/ )
if ( $line1=~m/$line2/)
What is the significance of '~' in matching.
Thanks in advance
CoolBhai (5 Replies)
Hello experts,
I have a file containing the following text(shortened here).
File Begin
----------
< # Billboard.d3fc1302a677.imagePath=S:\\efcm_T4
< Billboard.d3fc1302a677.imagePath=S:\\efcm_T4
---
> # Billboard.d3fc1302a677.imagePath=S:\\efcm_Cassini
>... (2 Replies)
Hi experts,
I have many occurances of the following headers in a file. I need to grep for the word changed/inserted in the header, calculate the difference between the two numbers and list the count incrementally.
Headers in a file look like this:
-------------------
---------------------... (6 Replies)
I am doing a file patterhn matching for a text file in PERL
I am using this,,, but it says that no file is found
$filepattern = '\d{1,4}.*A0NW9693.NDM.HBIDT.*.AD34XADJ.txt';
Can anyone help me out with Perl Pattern Matching concepts and how to do pattern matching for this txt file:... (4 Replies)
I have a 2 files in .gz format and it consists of 5 million lines the format of the file would be
gzcat file1.gz | more
abcde
aerere
ffgh56
..
..
12345
gzcat file2.gz | more
abcde , 12345 , 67890,
ffgh56 , 45623 ,12334
whatever the string is in the file1 should be matched... (3 Replies)
My log file looks as given below, its actually a huge file around 1 GB and these are some of the line:
conn=5368758 op=10628050 msgId=64 - RESULT err=0 tag=101 nentries=1 etime=0
conn=7462122 op=-1 msgId=-1 - fd=247 slot=247 LDAPS connection from 10.13.18.12:37645 to 10.18.6.45
conn=7462122... (5 Replies)
Hi,
I have a list of IP, eg :
192.168.0.15
192.168.0.24
192.168.2.110
192.168.2.200
And I would like the shortest pattern who match with '192.168.0' and '192.168.2' (without the last dot and number). (7 Replies)
Discussion started by: X-Or
7 Replies
LEARN ABOUT DEBIAN
je::object::regexp
JE::Object::RegExp(3pm) User Contributed Perl Documentation JE::Object::RegExp(3pm)NAME
JE::Object::RegExp - JavaScript regular expression (RegExp object) class
SYNOPSIS
use JE;
use JE::Object::RegExp;
$j = new JE;
$js_regexp = new JE::Object::RegExp $j, "(.*)", 'ims';
$perl_qr = $js_regexp->value;
$some_string =~ $js_regexp; # You can use it as a qr//
DESCRIPTION
This class implements JavaScript regular expressions for JE.
See JE::Types for a description of most of the interface. Only what is specific to JE::Object::RegExp is explained here.
A RegExp object will stringify the same way as a "qr//", so that you can use "=~" on it. This is different from the return value of the
"to_string" method (the way it stringifies in JS).
Since JE's regular expressions use Perl's engine underneath, the features that Perl provides that are not part of the ECMAScript spec are
supported, except for "(?s)" and "(?m)", which don't do anything, and "(?|...)", which is unpredictable.
In versions prior to 0.042, a hyphen adjacent to "d", "s" or "w" in a character class would be unpredictable (sometimes a syntax error).
Now it is interpreted literally. This matches what most implementations do, which happens to be the same as Perl's behaviour. (It is a
syntax error in ECMAScript.)
METHODS
value
Returns a Perl "qr//" regular expression.
If the regular expression or the string that is being matched against it contains characters outside the Basic Multilingual Plane
(whose character codes exceed 0xffff), the behavior is undefined--for now at least. I still need to solve the problem caused by JS's
unintuitive use of raw surrogates. (In JS, "/../" will match a surrogate pair, which is considered to be one character in Perl. This
means that the same regexp matched against the same string will produce different results in Perl and JS.)
class
Returns the string 'RegExp'.
SEE ALSO
JE
JE::Types
JE::Object
perl v5.14.2 2012-03-18 JE::Object::RegExp(3pm)