Question

I have a directory with folder structure as follows:

DATA -- ABD 1231345 -- 2012_01_08
                    -- 2012_03_09
                    -- 2012_06_11

     -- DEF 4859480 -- 2012_02_10
                    -- 2012_05_10
                    -- 2012_07_10

What I’m trying to do is:

• cd DATA
• run a bash script (while in /DATA) that will rename all first-child folders from

ABD 1231345

to

ABD_1231345

Do you have a suggestion on how to accomplish using command line on Mac OSX / unix?

Answer 1

for i in *; do mv "$i" "${i// /_}"; done

Note that the ${i//string/repl} syntax is a non-standard extension of sh, but you can do the same thing portably with something like:

for i in *; do j=$( echo "$i" | tr ' ' _); mv "$i" "$j"; done