MKDIR(2)

NAME
mkdir - make a directory file

SYNOPSIS
#include <sys/stat.h>
int
mkdir(const char *path, mode_t mode);

DESCRIPTION
The directory path is created with the access permissions specified by mode and restricted by the umask(2) of the calling process. See chmod(2) for the possible permission bit masks for mode.

The directory's owner ID is set to the process's effective user ID. The directory's group ID is set to that of the parent directory in which it is created.

Note: the behavior of mkdir() is undefined when mode bits other than the low 9 bits are used. Use chmod(2) after mkdir() to explicitly set the other bits (See example below).

RETURN VALUES
A 0 return value indicates success. A -1 return value indicates an error, and an error code is stored in errno.

ERRORS
Mkdir() will fail and no directory will be created if:

[EACCES]
    Search permission is denied for a component of the path prefix.

[EACCES]
    Write permission is denied for the parent directory.

[EDQUOT]
    The new directory cannot be created because the user's quota of disk blocks on the file system that will contain the directory has been exhausted.

[EDQUOT]
    The user's quota of inodes on the file system on which the directory is being created has been exhausted.

[EEXIST]
    The named file exists.

[EFAULT]
    Path points outside the process's allocated address space.

[EIO]
    An I/O error occurred while making the directory entry or allocating the inode.

[EIO]
    An I/O error occurred while reading from or writing to the file system.

[ELOOP]
    Too many symbolic links were encountered in translating the pathname. This is taken to be indicative of a looping symbolic link.

[EMLINK]
    The parent directory already has {LINK_MAX} links.

[ENAMETOOLONG]
    A component of a pathname exceeded {NAME_MAX} characters, or an entire path name exceeded {PATH_MAX} characters.

[ENOENT]
    A component of the path prefix does not exist or path is an empty string.

[ENOSPC]
    The new directory cannot be created because there is no space left on the file system that would contain it.

[ENOSPC]
    There are no free inodes on the file system on which the directory is being created.

[ENOTDIR]
    A component of the path prefix is not a directory.

[EROFS]
    The parent directory resides on a read-only file system.

EXAMPLE

    int main (int argc, const char * argv[])
    {
    	/* The behavior of mkdir is undefined for anything other than the "permission" bits */
    	if (mkdir("/tmp/blah", 0777))
    		perror("/tmp/blah");
    	/* So we need to set the sticky/executable bits explicitly with chmod after calling mkdir */
    	if (chmod("/tmp/blah", 07777))
    		perror("/tmp/blah");
    }

LEGACY SYNOPSIS
#include <sys/types.h> #include <sys/stat.h>

The include file <sys/types.h> is necessary.

SEE ALSO
chmod(2), stat(2), umask(2), compat(5)

STANDARDS
The mkdir() function conforms to p1003.1-88.