I am trying to devise a Perl regex as an if condition that identifies | but will fail if the | is contained anywhere in a quoted string such as 'It went >| CRASH |< as it fell on the floor'
Example inputs are below
This should match:
action 71|55|279|286|155|57|343
This should fail to match:
action mud_destroyset($me,$arg,$arg1,$arg2,'gun','2','There is an almighty >| CRASH |< . When the smoke clears, both door and sphere are gone...','You hear the >| CRASH |< of a cannon going off in the distance.','',0,$cid,$oc) ;
I have tried negative lookbehind regex as follows and fiddled extensively and failed. I even asked ChatGPT and it failed.
These didn't work (the 1st one is ChatGPT solution, the 2nd is my attempt):
^(?:(?!'\|).)*\|
(?<!'). \|.
https://regex101.com/r/1o0SOM/1
https://regex101.com/r/z5Xz83/1
Help appreciated!
CodePudding user response：
One way could be removing anything between single quotes and then looking for the pipe:
index($txt =~ s/'[^']*'//gr, "|") != -1
An example run:
use strict;
use warnings;
my @texts = ("action 71|55|279|286|155|57|343",
"action 'There is this >| CRASH |< .'");
for my $txt (@texts) {
print index($txt =~ s/'[^']*'//gr, "|") != -1 ? "yes\n" : "no\n";
}
which gives
yes
no
': literal single quote[^']*: anything but single quote, repetad as many times as possible': again a literal single quote- "g" flag: global replacement
- "r" flag: nondestructive, i.e., return a new string
and index function looks for the substring ("|") and returns -1 if it cannot find it in the searched string.
CodePudding user response：
After some experimentation I found a solution that worked for me, although it is not perfect as it will not produce a match if there is any string literal before the pipe, but works for all my input data cases.
^(?!.*\').*\|
https://regex101.com/r/QZKMKS/1
A more sophisticated solution was also suggested on reddit:
'[^'] '(*SKIP)(*F)|\|