mkdir -p issue while bash scripting

Question

I am attempting to create a recursive directory tree with some nested directories along the way.

While testing this manually in bash it functions without issue. However while testing this command in a bash script it is broken...instead of creating the directory tree, it creates two directories '{dir1,dir2/' and then {subdir1,subdir2},dir3,dir4} inside of the first.

Here is the command:

mkdir -p main/{dir1,dir2/{subdir1,subdir2},dir3,dir4}

Any thoughts?

Thanks!

Instead of creating the directory tree is creates two directorys '{dir1,dir2/' and then '{subdir1,subdir2},dir3,dir4}' inside of the first. — unixnerd, Sep 05 '15 at 00:56
This executes as expected for me, are you **certain** you are using the same command in both cases? Does the script contain any other commands that might alter this one? — Dimitris Fasarakis Hilliard, Sep 05 '15 at 01:09
Same for me. Are you sure you're not running it in `sh`/`dash`? — Reinstate Monica Please, Sep 05 '15 at 01:11
Yes I copy and paste the command out of my bash script. The command works manually but not in the script. And yes I am running bash for sure. — unixnerd, Sep 05 '15 at 01:14
@techno-shaman Depends on your system, but generally yes. `#!/bin/sh` is very often `dash`, not `bash` — Reinstate Monica Please, Sep 05 '15 at 01:16
See [this](http://stackoverflow.com/a/10383546/3076724) or [this](http://askubuntu.com/a/141932/234837) for an explenation — Reinstate Monica Please, Sep 05 '15 at 01:21
It was the #! I was using. Thanks! This is good to know. I'd been using #!/bin/bash forever but started #!/bin/sh recently because I saw someone else using it. Didn't think it would cause this sort of problem! Thanks!! — unixnerd, Sep 05 '15 at 01:23

score 3 · Answer 1 · answered Sep 05 '15 at 01:22

Your script is being run by /bin/sh, which in your case is not bash but rather some Posix-compatible shell, quite possibly dash.

Brace expansion is a shell extension implemented by quite a few shells, including bash, ksh and zsh, but it is not available in dash.

Make sure that your shebang line specifies bash:

#!/bin/bash

mkdir -p issue while bash scripting

1 Answers1