Bash - String replace at the end with a regex
 

Hi,
I want to remove the last foldername in a string variable:
"hello/mr/robinson/"
should become
"hello/mr/"

I am trying it the following way:

a="hello/mr/robinson/"
echo ${a//[^\/]*\/$/}

But it seems that ${} does not recognize $ as end of string delimiter.
Any ideas?

Hello, how about
dirname $a
Cheers, Tom.

thanks. this works in that example, but it would still be nice to know what kind of regex are useable in ${} expressions. Also, the dirname solution seems to be slower than a ${} expression.

I also just noticed that with dirname I will get a ".", if I have "hello/" for example. But I want that to become ""

Hi,

try this:
This will only work if your path does end with a slash '/'.

A few more notes:
The part in bold is called an extended pattern. You might have to set it in bash before you can use it:
It is NOT a RegEx. Bash does not recognize RegEx within String manipulation. Therefore your '$' at the end does not work as you expected it to.

Hope this helps.

thanks a lot:
got me the result I wanted.

Oops
 

Somehow I misread you first post and I thought you just wanted the last part to keep. Well, glad you filtered out the useful part of my suggestion.

parameter expansions don't use regular expressions, they follow shell globbing rules.

Don't forget that you can also add characters back to the string after expansion, which may help simplify things in some places. To retain the following backslash on "/hello/mr/", for example, you could simply do this: