Re: [Help-bash] Getting rid of white space with % and %%

[Greg Wooledge]

On Mon, May 21, 2012 at 03:17:53PM -0600, Bill Gradwohl wrote:
> I noticed it's apparently legit to say the following:
> 
> string='hello this  is   a    test     '
> echo "'${string}'" original
> 
> echo "'${string%[[:space:]]}'"
> echo "'${string%[[:space:]]*}'"
> echo "'${string%%[[:space:]]*}'"

It appears you are trying to trim all the trailing whitespace from a
string variable.  You can do that with extended globs:

shopt -s extglob
echo "'${string%%+([[:space:]])}'"

Or if you don't want to use extended globs, you can do it two steps:

remove=${string##*[![:space:]]}
echo "'${string%$remove}'"

Normal globs (like the ones you were attempting to use) do not have a
full closure operator, so you can't say "0 or more spaces".