Creating nested directories

Question

I want to write a bash script that will get a command line argument and create nested directories under the user home directory. E.g a/b/c

mkdir -p $1/$2/$3

But I want create not just three levels of directories, I want get command line argument 3 or 5 and create necessary quantity of nested directories

Answer 1

#!/bin/sh

(
    IFS=/
    mkdir -p "$*"
)

The expansion of "$*" will be a single quoted string consisting of all arguments to the script concatenated together with the first character of $IFS as a delimiter. This is why we also set $IFS to /.

I'm running that in a subshell to avoid setting IFS for the rest of the script (it changes the behavior of certain things, like how read works). If there's nothing else in the script, you can leave ( and ) out.

Testing:

$ tree
.
`-- script.sh

0 directory, 1 file

$ ./script.sh 1 2 3 4 {a..k}

$ tree
.
|-- 1
|   `-- 2
|       `-- 3
|           `-- 4
|               `-- a
|                   `-- b
|                       `-- c
|                           `-- d
|                               `-- e
|                                   `-- f
|                                       `-- g
|                                           `-- h
|                                               `-- i
|                                                   `-- j
|                                                       `-- k
`-- script.sh

15 directories, 1 file

Answer 2

You can set the inter field separator $IFS to /, then "$*" will expand to a/b/c/...:

IFS=/
mkdir -p "$*"