1

I want to find, in all the files in a directory, the pattern

t00 = 290
or
t00     = 300
or
t00 =    -278
...

in other words: (string "t00") + (1 or more white spaces) + (symbol "=") + (1 or more white spaces) + (perhaps a negative sign) + (number)

I have tried

grep -E "t00 += +-?\d" *

but it is not working as desired. Just trying I did

grep -P "t00 += +-?\d" *

and it works for Perl expressions. What am I do wrong in the case of extended regular expressions? I would like to use extended regular expressions instead of Perl because I have heard it is more common/universal (I may be wrong in this, though). Thx.

1
  • 1
    see Why does my regular expression work in X but not in Y? .. wrt BRE/ERE being common, that is the case with cli tools like grep/sed/awk .. regex in programming languages like perl, python, ruby, js, etc are all different in their own ways but certainly more featured than BRE/ERE – Sundeep Apr 30 '20 at 14:12
4

The problem is the \d statement which is not part of the extended regular expression standard. You could try the [[:digit:]] POSIX character class (or [0-9] on implementations that don't understand those) instead.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.