selectively remove blank spaces from string

Cpt_Cell · 10-07-2009, 01:07 PM

Hi,

I'm a newbie to shell scripting and I have the following problem:

I need all spaces between two letters or a letter and a number exchanged for an underscore, but all spaces between a letter and other characters need to remain.

One example for clarity:

Input:

force -- lamin 90 [label]
active A -- generation [label]

needed Output:

force -- lamin_90 [label]
active_A -- generation [label]

I tried solving this with sed but obviously s/ /_/g does not work, nor does any s/[a-zA-z0-9] [a-zA-z0-9]/[a-zA-z0-9]_[a-zA-z0-9]/g , because you just can't do this...

Can anyone help me?
Thanks in advance!
Matthias

vonbiber · 10-07-2009, 02:46 PM

Code:

sed 's/\([a-zA-Z0-9]\) \{1,\}\([a-zA-Z0-9]\)/\1_\2/g'

should do the job
any sequence of
letter/digit followed by 1 space or more and followed
by a letter/digit
is replaced by
the 1st letter/digit followed by '_' and the 2nd letter/digit

Cpt_Cell · 10-08-2009, 02:41 AM

Works!
Thanks a lot for the reply!