Perl One Liner Regular Expressions

stallion has asked for the wisdom of the Perl Monks concerning the following question:

Is there any regex to delete a complete line and replace with another line....

For eg:

macros perl
macros monks
macros one liner
macros

have to be converted as 

macros regex
macros regex
macros regex
macros regex
[download]

Whatever follows macros whether it is empty or followed by a string have to be replaced with regex and All macros will be at the beginning of the line so we can include ^ character in the regex.

Thanks Monks

Comment on Perl One Liner Regular Expressions Download Code

Replies are listed 'Best First'.
Re: Perl One Liner Regular Expressions by cheekuperl (Monk) on Aug 16, 2012 at 11:20 UTC
Ammm...btw..one way of doing it is like this: `sed -n -e 's/^macros .*/macros regex/gp' <file>` [download]	[reply] [d/l]
Re: Perl One Liner Regular Expressions by uday_sagar (Scribe) on Aug 16, 2012 at 11:44 UTC
Stallion, Put your contents in monks.txt and give the following one liner. `perl -p -i -e "s/^macros(.)*/macros\ regex/g" monks.txt` :-)	[reply] [d/l]
Re^2: Perl One Liner Regular Expressions by hbm (Hermit) on Aug 16, 2012 at 13:32 UTC
No need for parentheses; nor to escape the space; nor for the 'g' modifier - '.' will gobble everything up, thus there can be only one match. So: `perl -p -i -e "s/^macros./macros regex/" monks.txt # or perl -p -i -e "s/^macros\K.*/ regex/" monks.txt` [download]	[reply] [d/l]
Re^2: Perl One Liner Regular Expressions by cheekuperl (Monk) on Aug 16, 2012 at 13:20 UTC
The grouping is not really required. This works pretty fine: `s/^macros.*/macros regex/` [download]	[reply] [d/l]
Re: Perl One Liner Regular Expressions by cheekuperl (Monk) on Aug 16, 2012 at 11:17 UTC
Show us your code :)	[reply]