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this might seem like stupid Q but I have PS problem: like the title says I try something like:

 $all = gci D:\work\
 $all | Select-String ".*_.*=-1"

(im looking for config option that has value -1 and _ in name) Problem is that PS freezes, aka it doesnt finish in reasonable time, ctrl +c doesnt work. Ofc you could say that data is just to much for it to process, but problem is that grep takes like 1-2 secs on same folder and same regex.

Grep command is (originally it didnt have -r but I added it after some comments, grep is still fast but it takes 20-30 sec)

grep ".*_.*=-1" -r D:\work\*


$all  | ForEach-Object {echo $_.Name;  $_|Select-String ".*_.*=-1"      }

shows slowly filenames... I guess the problem is that Regex speed in PS is pathetic...

share|improve this question
Could you please show the full grep command as well. – bbaja42 Oct 19 '12 at 12:57
i could and i did :) – NoSenseEtAl Oct 19 '12 at 13:07

Try tweaking a regex to


equivalent grep version :

grep -P '[^_]*_[^=]*=-1'

The regex implementations are different, so that is the reason for different behavior. I don't know specifics of powershell regex implementation, so I don't know the exact reason.

share|improve this answer
is the regex semantics the same for my example (in grep and PS) – NoSenseEtAl Oct 19 '12 at 12:38
I don't know. Even grep as more than 1 regular expression syntax. Regular, extended and perl version. I'm not experienced with the PS version. – bbaja42 Oct 19 '12 at 12:44
btw it still freezes – NoSenseEtAl Oct 19 '12 at 12:46
Could you give more details on the data sample, like size in MB? – bbaja42 Oct 19 '12 at 12:47
btw maybe PS tries to go through directories while grep skips them "X is a directory" – NoSenseEtAl Oct 19 '12 at 12:48

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