MKDIR(P) POSIX Programmer's Manual MKDIR(P)NAMEmkdir - make a directory
SYNOPSIS
#include <sys/stat.h>
int mkdir(const char *path, mode_t mode);
DESCRIPTION
The mkdir() function shall create a new directory with name path. The
file permission bits of the new directory shall be initialized from
mode. These file permission bits of the mode argument shall be modified
by the process' file creation mask.
When bits in mode other than the file permission bits are set, the
meaning of these additional bits is implementation-defined.
The directory's user ID shall be set to the process' effective user ID.
The directory's group ID shall be set to the group ID of the parent
directory or to the effective group ID of the process. Implementations
shall provide a way to initialize the directory's group ID to the group
ID of the parent directory. Implementations may, but need not, provide
an implementation-defined way to initialize the directory's group ID to
the effective group ID of the calling process.
The newly created directory shall be an empty directory.
If path names a symbolic link, mkdir() shall fail and set errno to
[EEXIST].
Upon successful completion, mkdir() shall mark for update the st_atime,
st_ctime, and st_mtime fields of the directory. Also, the st_ctime and
st_mtime fields of the directory that contains the new entry shall be
marked for update.
RETURN VALUE
Upon successful completion, mkdir() shall return 0. Otherwise, -1 shall
be returned, no directory shall be created, and errno shall be set to
indicate the error.
ERRORS
The mkdir() function shall fail if:
EACCES Search permission is denied on a component of the path prefix,
or write permission is denied on the parent directory of the
directory to be created.
EEXIST The named file exists.
ELOOP A loop exists in symbolic links encountered during resolution of
the path argument.
EMLINK The link count of the parent directory would exceed {LINK_MAX}.
ENAMETOOLONG
The length of the path argument exceeds {PATH_MAX} or a pathname
component is longer than {NAME_MAX}.
ENOENT A component of the path prefix specified by path does not name
an existing directory or path is an empty string.
ENOSPC The file system does not contain enough space to hold the con‐
tents of the new directory or to extend the parent directory of
the new directory.
ENOTDIR
A component of the path prefix is not a directory.
EROFS The parent directory resides on a read-only file system.
The mkdir() function may fail if:
ELOOP More than {SYMLOOP_MAX} symbolic links were encountered during
resolution of the path argument.
ENAMETOOLONG
As a result of encountering a symbolic link in resolution of the
path argument, the length of the substituted pathname string
exceeded {PATH_MAX}.
The following sections are informative.
EXAMPLES
Creating a Directory
The following example shows how to create a directory named
/home/cnd/mod1, with read/write/search permissions for owner and group,
and with read/search permissions for others.
#include <sys/types.h>
#include <sys/stat.h>
int status;
...
status = mkdir("/home/cnd/mod1", S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
APPLICATION USAGE
None.
RATIONALE
The mkdir() function originated in 4.2 BSD and was added to System V in
Release 3.0.
4.3 BSD detects [ENAMETOOLONG].
The POSIX.1-1990 standard required that the group ID of a newly created
directory be set to the group ID of its parent directory or to the
effective group ID of the creating process. FIPS 151-2 required that
implementations provide a way to have the group ID be set to the group
ID of the containing directory, but did not prohibit implementations
also supporting a way to set the group ID to the effective group ID of
the creating process. Conforming applications should not assume which
group ID will be used. If it matters, an application can use chown() to
set the group ID after the directory is created, or determine under
what conditions the implementation will set the desired group ID.
FUTURE DIRECTIONS
None.
SEE ALSOumask() , the Base Definitions volume of IEEE Std 1003.1-2001,
<sys/stat.h>, <sys/types.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 MKDIR(P)
