How to mkdir only if a directory does not already exist?
ShellScriptingKshAixMkdirShell Problem Overview
I am writing a shell script to run under the KornShell (ksh) on AIX. I would like to use the mkdir
command to create a directory. But the directory may already exist, in which case I do not want to do anything. So I want to either test to see that the directory does not exist, or suppress the "File exists" error that mkdir
throws when it tries to create an existing directory.
How can I best do this?
Shell Solutions
Solution 1 - Shell
Try mkdir -p
:
mkdir -p foo
Note that this will also create any intermediate directories that don't exist; for instance,
mkdir -p foo/bar/baz
will create directories foo
, foo/bar
, and foo/bar/baz
if they don't exist.
Some implementation like GNU mkdir
include mkdir --parents
as a more readable alias, but this is not specified in POSIX/Single Unix Specification and not available on many common platforms like macOS, various BSDs, and various commercial Unixes, so it should be avoided.
If you want an error when parent directories don't exist, and want to create the directory if it doesn't exist, then you can test
for the existence of the directory first:
[ -d foo ] || mkdir foo
Solution 2 - Shell
This should work:
$ mkdir -p dir
or:
if [[ ! -e $dir ]]; then
mkdir $dir
elif [[ ! -d $dir ]]; then
echo "$dir already exists but is not a directory" 1>&2
fi
which will create the directory if it doesn't exist, but warn you if the name of the directory you're trying to create is already in use by something other than a directory.
Solution 3 - Shell
Use the -p flag.
man mkdir
mkdir -p foo
Solution 4 - Shell
Defining complex directory trees with one command
mkdir -p project/{lib/ext,bin,src,doc/{html,info,pdf},demo/stat/a}
Solution 5 - Shell
If you don't want to show any error message:
[ -d newdir ] || mkdir newdir
If you want to show your own error message:
[ -d newdir ] && echo "Directory Exists" || mkdir newdir
Solution 6 - Shell
mkdir foo
works even if the directory exists.
To make it work only if the directory named "foo" does not exist, try using the -p
flag.
Example:
mkdir -p foo
This will create the directory named "foo" only if it does not exist. :)
Solution 7 - Shell
The old tried and true
mkdir /tmp/qq >/dev/null 2>&1
will do what you want with none of the race conditions many of the other solutions have.
Sometimes the simplest (and ugliest) solutions are the best.
Solution 8 - Shell
You can either use an if
statement to check if the directory exists or not. If it does not exits, then create the directory.
-
dir=/home/dir_name
if [ ! -d $dir ] then mkdir $dir else echo "Directory exists" fi
-
You can directory use mkdir with -p option to create a directory. It will check if the directory is not available it will.
mkdir -p $dir
mkdir -p also allows to create the tree structure of the directory. If you want to create the parent and child directories using same command, can opt mkdir -p
mkdir -p /home/parent_dir /home/parent_dir/child1 /home/parent_dir/child2
Solution 9 - Shell
mkdir does not support -p switch anymore on Windows 8+ systems.
You can use this:
IF NOT EXIST dir_name MKDIR dir_name
Solution 10 - Shell
directory_name = "foo"
if [ -d $directory_name ]
then
echo "Directory already exists"
else
mkdir $directory_name
fi
Solution 11 - Shell
Simple, silent and deadly:
mkdir -p /my/new/dir >/dev/null 2>&1
Solution 12 - Shell
Or if you want to check for existence first:
if [[ ! -e /path/to/newdir ]]; then
mkdir /path/to/newdir
fi
-e is the exist test for KornShell.
You can also try googling a KornShell manual.
Solution 13 - Shell
This is a simple function (Bash shell) which lets you create a directory if it doesn't exist.
#------------------------------------------#
# Create a directory if it does not exist. #
#------------------------------------------#
# Note the "-p" option in the mkdir #
# command which creates directories #
# recursively. #
#------------------------------------------#
createDirectory() {
mkdir -p -- "$1"
}
You can call the above function as:
> createDirectory "$(mktemp -d dir-example.XXXXX)/fooDir/BarDir"
The above creates fooDir and BarDir if they don't exist. Note the "-p" option in the mkdir command which creates directories recursively.
Solution 14 - Shell
Referring to man page man mkdir
for option -p
-p, --parents
no error if existing, make parent directories as needed
which will create all directories in a given path, if exists throws no error otherwise it creates all directories from left to right in the given path. Try the below command. the directories newdir
and anotherdir
doesn't exists before issuing this command
Correct Usage
mkdir -p /tmp/newdir/anotherdir
After executing the command you can see newdir
and anotherdir
created under /tmp. You can issue this command as many times you want, the command always have exit(0)
. Due to this reason most people use this command in shell scripts before using those actual paths.
Solution 15 - Shell
mkdir -p sam
- mkdir = Make Directory
- -p = --parents
- (no error if existing, make parent directories as needed)
Solution 16 - Shell
if [ !-d $dirName ];then
if ! mkdir $dirName; then # Shorter version. Shell will complain if you put braces here though
echo "Can't make dir: $dirName"
fi
fi