sed headache


 
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# 1  
Old 10-13-2005
Data sed headache

Hi all,

I've got a thorny sed/regex problem and I thought somebody out there might be able to help.
I'd like to use sed in a Makefile to parse a path string. The path might look like this:
case 1: /mnt/users/bob/build/src
or
case 2: /mnt/users/bob/build/src/foo
or
case 3: /mnt/users/bob/build/src/foo/bar/src/more/src

I'd like to write a sed command which returns the string "/mnt/users/bob/build" in all cases.
Here's what I have so far:
sed -e "s^\(.*\)/src/.*^\1^g"

This works well for case 2, but not 1 or 3. I could use brute force repetition:
sed -e "s^\(.*\)/src/.*^\1^g" -e "s^\(.*\)/src/.*^\1^g" -e "s^\(.*\)/src/.*^\1^g" -e "s^\(.*\)/src/.*^\1^g"

to handle case 3, but that's downright ugly and still doesn't handle case 1.
To handle case 1 I tried this:
sed -e "s^\(.*\)/src\$^\1^g"

but this just gives an error message (maybe the end-of-line $ is not escaped properly?)

Arrgh!
Can someone please help?
# 2  
Old 10-13-2005
You were so close! Your error is putting a slash after src in your RE.

sed 's^\(.*\)/src.*^\1^'
# 3  
Old 10-13-2005
Thanks, Perderabo! That works for case #1, but still doesn't work for case #3. Is there any way to do a recursive regex search/replace - a search that continues until it doesn't find any more matches?
# 4  
Old 10-13-2005
Code:
$ echo $case1
/mnt/users/bob/build/src
$ echo $case2
/mnt/users/bob/build/src/foo
$ echo $case3
/mnt/users/bob/build/src/foo/bar/src/more/src
$ echo "$case1" | sed 's^\([^(src)]*\)/src.*^\1^'
/mnt/users/bob/build
$ echo "$case2" | sed 's^\([^(src)]*\)/src.*^\1^'
/mnt/users/bob/build
$ echo "$case3" | sed 's^\([^(src)]*\)/src.*^\1^'
/mnt/users/bob/build

Cheers
ZB
# 5  
Old 10-14-2005
Dude - that's extremely cool.
But now I'm confused - why does that work?
And after playing around a bit - why does
sed 's^\([^\]\)/src.*^\1^'
also work?
Thanks!
 
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