What does the mkdir -p mean in a script file?

Question

I have found a part of script like this In xx.sh：

BUILD_BOOT=.
mkdir -p $BUILD_BOOT

Can anybody help to explain what's the script above for as the directory parameter is .?

Answer 1

-p is short for --parents - it creates the entire directory tree up to the given directory.

E.g., suppose there are no directories in your current directory. If you execute:

mkdir a/b/c

It will fail, since you do not have an a subdirectory.

On the other hand

mkdir -p a/b/c

Will create the entire structure - a/b/c

Answer 2

mkdir -p means: create the directory and, if required, all parent directories. The fact that this makes little sense when the path is specified as ., so the current working directory, does not change this. Most likely the line where the path is defined is meant to be adapted as required.

In general: consult the linux manual pages for questions about commands and their options like this: man mkdir. A great source of information!

Answer 3

See mkdir.

It creates all the intermediate directories on the path to the final directory that do not already exist (as well as the final directory), and doesn't fail if the target directory already exists.

In context, it is pointless; if the BUILD_ROOT is the current directory, it already exists. At some time, the BUILD_ROOT must have been a longer path.