Question

I’m trying to match if any string exists after a certain pattern.
The pattern is “pattern” ‘anything in between’ “[after]”. case insensitive.

e.g

pattern 1 [after] ABC
pattern 2 [after] 123 abc DEX
pattern 3 [after] 
pattern 12345123 [after]
pattern @ASd#98 @_90sd [after] xyz dec
[after] 4 pattern

So the result I would like to obtain is,

pattern 1 [after] ABC
pattern 2 [after] 123 abc DEX
pattern @ASd#98 @_90sd [after] xyz dec

It begins with “pattern” and ends with “[after], anything sandwiched between is also accepted.

I’m having difficulty incorporating the delimits of [ ] & if string exists together.

I’ve tried, the closest I’ve gotten ends up matching

m/pattern/ ../ \[after]/

pattern 1 [after] ABC
pattern 2 [after] 123 ABC DEX
pattern 3 [after] 
pattern 12345123 [after]
pattern @ASd#98 @_90sd [after] xyz dec

But I don’t need the 3rd or 4th pattern as it doesn’t hold any numerics or characters after “[after]”.

Thanks

Answer 1

Here is the code I used to test against your input (which I just cat’ed and piped to the script)

#!/usr/bin/perl

while(<>)
{
    print if (/^pattern.*\[after\]\s*\S+/);
}

So to break it down for you:

/^pattern : match any string that begins with “pattern”

.*\[after\] : match any characters followed by “[after]”

\s*\S+ : match 0 or more whitespace characters followed by one or more non-whitespace character

That should give you enough to work with to tweak it up as you see fit.