How do you “debug” a regular expression with sed?

Question

I'm trying to use a regexp using sed. I've tested my regex with kiki, a gnome application to test regexpd, and it works in kiki.

date: 2010-10-29 14:46:33 -0200;  author: 00000000000;  state: Exp;  lines: +5 -2;  commitid: bvEcb00aPyqal6Uu;

I want to replace author: 00000000000; with nothing. So, I created the regexp, that works when I test it in kiki:

author:\s[0-9]{11};

But doesn't work when I test it in sed.

sed -i "s/author:\s[0-9]{11};//g" /tmp/test_regex.txt

I know regex have different implementations, and this could be the issue. My question is: how do I at least try do "debug" what's happening with sed? Why is it not working?

Answer 1

That looks more like a perl regex than it does a sed regex. Perhaps you would prefer using

perl -pi.orig -e 's/author:\s[0-9]{11};//g' file1 file2 file3

At least that way you could always add -Mre=debug to debug the regex.

Answer 2

In sed you need to escape the curly braces. "s/author:\s[0-9]\{11\};//g" should work.

Sed has no debug capability. To test you simplify at the command line iteratively until you get something to work and then build back up.

command line input:

$ echo 'xx a: 00123 b: 5432' | sed -e 's/a:\s[0-9]\{5\}//'

command line output:

xx  b: 5432