What does the -p flag do in "mkdir -p"?

Question

What does the -p flag do in mkdir -p?

Answer 1

The -p flag will create nested directories, but only if they don't exist already.

For example, suppose you have a directory /foo that you have write permissions for.

mkdir -p /foo/bar/baz  # creates bar and baz within bar under existing /foo

It is also an idempotent operation, because if you run the same command over again, you will not get an error, but nothing will be created.

Answer 2

This -p flag allows a parent folder to be created along with the nested folder.

For example:

mkdir directory/nested_directory 

it would return the following error : mkdir: cannot create directory ‘directory/nested_directory’: No such file or directory

But if you use -p such as:

mkdir -p directory/nested_directory

It will create both directory and it's nested nested_directory folders successfully.

Answer 3

It actually does two different things.

1. No error if existing
   • Prints no errors like mkdir: cannot create directory ‘<dir>’: File exists
2. Make parent directories as needed
   • You may create nested directories like mkdir -p dir1/dir2/dir3
   • The containing directories (in example: dir1, dir2) will be unaffected by file mode options (-m)