sed - last occurence of a match
 

Using sed, how do I remove everything after the last dash (-) in a string?

So how do I turn

'blah-blah-123' or 'blah-blah-blah-123'

into

'blah-blah' or 'blah-blah-blah'

respectively?

--
mr. scary

Matches a hyphen, then any number of characters except a hyphen, until the end of the line. This means that only the last occurrence of the hyphen satisfies the string.

Moin,

regular expressions are greedy (they catch the longest part of a line, which matches the pattern), so this will work:
Jan

P.S.: The only one exception from the "greedy behaviour" is the "?" quantifier in Perl compatible regular expressions (not supported by grep and sed).

Thank you jan61. That works (your explanation is a nice bonus). I did, however, need to escape the parentheses.

You can use a simple parameter substitution instead of sed:

Ha. Changed to the parameter substitution solution instead. Great solutions guys.

Awww, I almost mentioned the parameter substitution thing myself, but decided against it because the OP specifically asked for a sed solution. Since substitution requires the use of a variable, it's less convenient than sed when doing things like working with a text file, and since the purpose of the change wasn't mentioned I decided not to presume. :(

This is a good example of why questions like this really ought to be goal-centered: "how can I accomplish x", rather than process-centered: "how can I make y do x". :)


PS: If you use the -r switch in sed you don't need to escape the parentheses.

Moin,

did you use the -r option (extended regex)?

Jan