?= in perl regex


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting ?= in perl regex
# 1  
Old 12-28-2013
?= in perl regex

Could anyone please make me understand how the ?= works below ..

After executing this I am getting the same output.

Code:
$string="I love chocolate.";
$string =~ s/chocolate(?= ice)/vanilla/;
print "$string\n";

# 2  
Old 12-29-2013
Try this Smilie

Code:
$string="I love chocolate ice.";
$string =~ s/chocolate(?= ice)/vanilla/;
print "$string\n";

# 3  
Old 12-29-2013
Quote:
Originally Posted by scriptscript
Could anyone please make me understand how the ?= works below ..
Code:
perldoc perlre

Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Perl REGEX help

Experts - I found a script on one of the servers that I work on and I need help understanding one of the lines. I know what the script does, but I'm having a hard time understanding the grouping. Can someone help me with this? Here's the script... #!/usr/bin/perl use strict; use... (2 Replies)
Discussion started by: timj123
2 Replies

2. Shell Programming and Scripting

Perl, RegEx - Help me to understand the regex!

I am not a big expert in regex and have just little understanding of that language. Could you help me to understand the regular Perl expression: ^(?!if\b|else\b|while\b|)(?:+?\s+){1,6}(+\s*)\(*\) *?(?:^*;?+){0,10}\{ ------ This is regex to select functions from a C/C++ source and defined in... (2 Replies)
Discussion started by: alex_5161
2 Replies

3. Programming

Perl regex

Hello, I'm trying to get a quick help on regex since i'm not a regular programmer. Below is the line i'm trying to apply my regex to..i want to use the regex in a for loop and this line will keep on changing. subject=... (4 Replies)
Discussion started by: jhamaks
4 Replies

4. Programming

Perl regex

Hi Guys I have the following regex $OSRELEASE = $1 if ($output =~ /(Mac OS X (Server )?10.\d)/); output is currently Mac OS X 10.7.5 when the introduction of Mac 10.8 output changes to OS X 10.8.2 they have dropped the Mac bit so i changed the regex to be (2 Replies)
Discussion started by: ab52
2 Replies

5. Programming

Perl regex

HI, I'm new to perl and need simple regex for reading a file using my perl script. The text file reads as - filename=/pot/uio/current/myremificates.txt certificates=/pot/uio/current/userdir/conf/user/gamma/settings/security/... (3 Replies)
Discussion started by: jhamaks
3 Replies

6. UNIX for Dummies Questions & Answers

Perl Regex Help!!!

Hi, I get the following when I cat a file *.log xxxxx ===== dasdas gwdgsg fdsagfsag agsdfag ===== random data ===== My output should look like : If the random data after the 2nd ==== is null then OK should be printed else the random data should be printed. How do I go about this... (5 Replies)
Discussion started by: manutd
5 Replies

7. Shell Programming and Scripting

Converting perl regex to sed regex

I am having trouble parsing rpm filenames in a shell script.. I found a snippet of perl code that will perform the task but I really don't have time to rewrite the entire script in perl. I cannot for the life of me convert this code into something sed-friendly: if ($rpm =~ /(*)-(*)-(*)\.(.*)/)... (1 Reply)
Discussion started by: suntzu
1 Replies

8. Shell Programming and Scripting

Perl regex

I have got numbers like l255677 l376039 l188144 l340482 l440700 l254113 to match the numbers starting with '13' what would be the regex =~/13(.*)/ =======>This is not working .... But for user123,user657 regex =~/user(.*)/ ========>works Thanks for help..!! (7 Replies)
Discussion started by: trina_1
7 Replies

9. Shell Programming and Scripting

Perl REGEX

Hi, Can anyone help me to find regular expression for the following in Perl? "The string can only contain lower case letters (a-z) and no more than one of any letter." For example: "table" is accepted, whether "dude" is not. I have coded like this: $str = "table"; if ($str =~ m/\b()\b/) {... (4 Replies)
Discussion started by: evilfreakz
4 Replies

10. Shell Programming and Scripting

q with Perl Regex

For a programming exercise, I am mean to design a Perl script that detects double letters in a text file. I tried the following expressions # Check for any double letter within the alphabet /+/ # Check for any repetition of an alphanumeric character /\w+/ Im aware that the... (8 Replies)
Discussion started by: JamesGoh
8 Replies
Login or Register to Ask a Question