topic Re: SAS regular expressions: combination of ^ and $ not working in SAS Programming

SAS regular expressions: combination of ^ and $ not working

HeidiDT — Fri, 28 Apr 2023 15:46:37 GMT

Hi All!

I am very new to regex - I am currently busy with an introductory course. But I have a problem where the regex works when I use it in a grep command, but when I translate it into SAS it doesn't work. Please don't leaugh at the very basic example lol, I have attached the input file and here is my code (extracting all lines that contains exactly 3 digits):

Grep command (returns the correct 3 lines):

grep -E '^[0-9]{3}$' regex18.txt

SAS code (returns 0 rows):

proc import file='/sas/batch/sasdata/users/heididt/regex/ExerciseInputFiles/regex18.txt' out=example replace;
getnames=NO;datarow=1;
run;

data example;
length var2 $8.;
set example;
var2=left(put(var1,8.));
run;

data example_out;
set example;
if prxmatch('/^[0-9]{3}$/',var2);
run;

Re: SAS regular expressions: combination of ^ and $ not working

Tom — Fri, 28 Apr 2023 15:59:58 GMT

SAS only has fixed length character variables.

So your test find find 3 digits will not work since instead of three digits you have 3 digits followed by 5 spaces.

You should be able to just add a TRIM() function call.

if prxmatch('/^[0-9]{3}$/',trim(var2));

Re: SAS regular expressions: combination of ^ and $ not working

HeidiDT — Fri, 28 Apr 2023 16:11:38 GMT

EXCELLENT - thanks so much!