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?
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
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.
Use the -p flag.
man mkdir
mkdir -p foo
Defining complex directory trees with one command
mkdir -p project/{lib/ext,bin,src,doc/{html,info,pdf},demo/stat/a}
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
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. :)
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.
Simple, silent and deadly:
mkdir -p /my/new/dir >/dev/null 2>&1
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
mkdir does not support -p switch anymore on Windows 8+ systems.
You can use this:
IF NOT EXIST dir_name MKDIR dir_name
directory_name = "foo"
if [ -d $directory_name ]
then
echo "Directory already exists"
else
mkdir $directory_name
fi
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.
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.
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.
Improvement on the 'classic' solution (by Brian Campbell) - to handle the case of symlink to a directory.
[ -d foo/. ] || mkdir foo
mkdir -p sam
mkdir = Make Directory
-p = --parents
(no error if existing, make parent directories as needed)
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
Related
mkdir $(date '+%d-%b-%Y')
then cd to the dynamically created directory
How to "cd" to a directory which is created using "mkdir $(date '+%d-%b-%Y')" and do the operations by moving into the created directory in bash script
Simple way would be, you store the directory name in a variable
dirname=$(date '+%d-%b-%Y')
if [ -n "$dirname" ]; then
mkdir "$dirname"
if [ -d "$dirname" ]; then
cd "$dirname"
fi
fi
Added some error handling and also if your file is written in Windows and being run in an unix environment or vice-versa, I would recommend using dos2unix which will handle the new line character conversions (this is for the ? characters OP is seeing in ls).
Can you show me your case?
In most cases, you should not cd in to the directory. Use absolute path instead:
Good practice:
mkdir /tmp/mydir/
cp -R /usr/local/example/ /tmp/mydir/
sed 's/foo/bar/g' /tmp/mydir/afile
Bad practice:
mkdir /tmp/mydir/
cd /tmp/mydir/
cp -R /usr/local/example/ .
sed 's/foor/bar/g' afile
P.S.
Subj:
$ mkdir $(date '+%d-%b-%Y')
$ cd $(date '+%d-%b-%Y')
$ pwd
/Users/user/18-Feb-2019
In Bash, $_ expands to the last argument to the previous command. So you could do:
mkdir $(date '+%d-%b-%Y')
cd $_
In a real Bash program you would want to quote the expansions (use Shellcheck on your code to check for missing quotes), and check for errors on both mkdir and cd.
I wrote this little shell script(test.sh) to create a basic folder structure:
#!/bin/bash
# Check if directory already exists,
# if it doesnt, create one.
if [ ! -d "~/.dir1" ]; then
mkdir ".dir1"
else
rm -rf ".dir1"
mkdir ".dir1"
fi
When I run
test.sh
in console, the hidden folder is created.
But:
When I run it again it tells me:
mkdir: .dir1: File exists
But it could exist because I removed it in my shell script before I created a new one!
So why does it display this message?
Thanks and greetings!
Replace
[ ! -d "~/.dir1" ]
by
[ ! -d "${HOME}/.dir1" ]
I would simply use -p.
mkdir -p "$HOME/dir1"
If you pass -p, mkdir wouldn't throw an error if the directory already exists, it would simply silently return in that case.
If you want to make sure folder is empty use this:
rm -rf "$HOME/dir1"
mkdir -p "$HOME/dir1"
and no if! The basic problem with the if is the fact that it is not immune against race conditions. When the script went off from CPU right after the if - and creates "dir1" - your script will fail when it enters the CPU again since it still thinks the directory does not exist.
What you are doing by "~/.dir1" is not right. It's just another string for a directory name literally "~/.dir1" i.e ~ is not being expanded to $HOME.
Use full path or ~/".dir1" or ~/.dir1 instead.
You can use $HOME too: $HOME/.dir1 or "$HOME/.dir1" or "$HOME"/".dir1" all of them will produce same result... but quoting variables is a good practice.
~ isn't expanded when you place it in quotes. You need to leave it unquoted.
if [ ! -d ~/.dir1 ]
Of note, you're checking for ~/.dir1 but you make .dir1. That's only the same directory if the current directory is ~. If it isn't, they're not the same.
Also, mkdir -p will do this for you, creating a directory only if it doesn't exist already. You could simplify your script to:
mkdir -p ~/.dir1
or
rm -rf ~/.dir1
mkdir ~/.dir1
What is a better way to create sub folders in a shell script? Instead of using the following method?
mkdir /var/log
mkdir /var/log/celery
mkdir /var/log/celery/stdout
mkdir /var/log/celery/stderr
touch /var/log/celery/stdout/stdout.log <<< I'm hoping the use this path create folder if doesn't exists....
touch /var/log/celery/stderr/stderr.log
mkdir has a -p flag that will create parent directories but touch will not create directories that do not exist.
That still cuts the above down to:
mkdir -p /var/log/celery/stdout /var/log/celery/stderr
touch /var/log/celery/stdout/stdout.log /var/log/celery/stderr/stderr.log
Which in a shell that supports brace expansion could even be:
mkdir -p /var/log/celery/{stdout,stderr}
touch /var/log/celery/{stdout/stdout.log,stderr/stderr.log}
And actually, if you have brace expansion but not mkdir -p you could do:
mkdir /var/log{,/celery{,/{stdout,stderr}}}
touch /var/log/celery/{stdout/stdout.log,stderr/stderr.log}
But there isn't any way to combine the mkdir and touch steps with standard tools that I'm aware of.
The -p option of mkdir will create the intermediate folders of the path if they don't exists (and of course, if you have the appropriate privileges):
mkdir -p /var/log/celery/stderr
To create the file, you can append the touch after the operator &&, so the touch operation only occurs if the directory either was created successfully or already exists:
mkdir -p /var/log/celery/stderr && touch "$_/stderr.log"
(Basically, the $_ will pass the dir path to the touch command)
UNTESTED:
$ needir () { mkdir -p $1; echo $1; }
$ touch $(needir /var/log/celery/stderr)/stderr.log
and put "needir" in your .profile, or better yet, in a function library on your path that you source when you login. you'd be surprised how often you'll be using it.
This question already has answers here:
How to mkdir only if a directory does not already exist?
(17 answers)
Closed 8 years ago.
In my bash script I do:
mkdir product;
When I run the script more than once I get:
mkdir: product: File exists
In the console.
So I am looking to only run mkdir if the dir doesn't exist. Is this possible?
Do a test
[[ -d dir ]] || mkdir dir
Or use -p option:
mkdir -p dir
if [ ! -d directory ]; then
mkdir directory
fi
or
mkdir -p directory
-p ensures creation if directory does not exist
Use mkdir's -p option, but note that it has another effect as well.
-p Create intermediate directories as required. If this option is not specified, the full path prefix of each oper-
and must already exist. On the other hand, with this option specified, no error will be reported if a directory
given as an operand already exists. Intermediate directories are created with permission bits of rwxrwxrwx
(0777) as modified by the current umask, plus write and search permission for the owner.
mkdir -p
-p, --parents
no error if existing, make parent directories as needed
Try using this:-
mkdir -p dir;
NOTE:- This will also create any intermediate directories that don't exist; for instance,
Check out mkdir -p
or try this:-
if [[ ! -e $dir ]]; then
mkdir $dir
elif [[ ! -d $dir ]]; then
echo "$Message" 1>&2
fi
How can I have the following command
echo "something" > "$f"
where $f will be something like folder/file.txt create the folder folder if does not exist?
If I can't do that, how can I have a script duplicate all folders (without contents) in directory 'a' to directory 'b'?
e.g if I have
a/f1/
a/f2/
a/f3/
I want to have
b/f1/
b/f2/
b/f3/
The other answers here are using the external command dirname. This can be done without calling an external utility.
mkdir -p "${f%/*}"
You can also check if the directory already exists, but this not really required with mkdir -p:
mydir="${f%/*}"
[[ -d $mydir ]] || mkdir -p "$mydir"
echo "something" | install -D /dev/stdin $f
try
mkdir -p `dirname $f` && echo "something" > $f
You can use mkdir -p to create the folder before writing to the file:
mkdir -p "$(dirname $f)"