mjhjmtu

mkdir -p /path/to/something

when does the above command exit with nonzero exit status?

Does it happen, if and only if /path/to/something doesn't exist as any file (or as a directory?) before running the command and the command fails to create it as a directory?

man mkdir says

 -p, --parents
 no error if existing, make parent directories as needed

Thanks.

To elaborate on the previous answer with a few examples.

It could be when trying to create folders inside system folders:

ubuntu:~$ mkdir /proc/test
mkdir: cannot create directory ‘/proc/test’: No such file or directory
ubuntu:~$ mkdir -p /dev/null/test
mkdir: cannot create directory ‘/dev/null’: Not a directory

Or when you don't have permission to the previous folder:

ubuntu:~$ mkdir -p /root/test
mkdir: cannot create directory ‘/root’: Permission denied

It will also fail if there is a file by the same name in the folder:

ubuntu:~$ touch /tmp/test
ubuntu:~$ mkdir -p /tmp/test
mkdir: cannot create directory ‘/tmp/test’: File exists

From https://www.gnu.org/software/coreutils/manual/html_node/mkdir-invocation.html#mkdir-invocation:

An exit status of zero indicates success, and a nonzero value indicates failure. 

Failure is when the directories need to be created but the operation fails.