NAME

       mkdir - 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 contents 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 ALSO

       umask() , 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)