Synopsis:
    #include <sys\types.h>
    #include <sys\stat.h>
    #include <fcntl.h>
    #include <io.h>
    int umask( int cmask );

Description:
    The umask function sets the process's file mode creation mask to cmask.
    The process's file mode creation mask is used during  creat,  open or
     sopen to turn off permission bits in the permission argument supplied.
    In other words, if a bit in the mask is on, then the corresponding bit
    in the file's requested permission value is disallowed.

    The argument cmask is a constant expression involving the constants
    described below.  The access permissions for the file or directory are
    specified as a combination of bits (defined in the <sys\stat.h> header
    file).

    The following bits define permissions for the owner.

    Permission     Meaning

S_IRWXU
    Read, write, execute/search

S_IRUSR
    Read permission

S_IWUSR
    Write permission

S_IXUSR
    Execute/search permission

    The following bits define permissions for the group.

    Permission     Meaning

S_IRWXG
    Read, write, execute/search

S_IRGRP
    Read permission

S_IWGRP
    Write permission

S_IXGRP
    Execute/search permission

    The following bits define permissions for others.

    Permission     Meaning

S_IRWXO
    Read, write, execute/search

S_IROTH
    Read permission

S_IWOTH
    Write permission

S_IXOTH
    Execute/search permission

    The following bits define miscellaneous permissions used by other
    implementations.

    Permission     Meaning

S_IREAD
    is equivalent to S_IRUSR (read permission)

S_IWRITE
    is equivalent to S_IWUSR (write permission)

S_IEXEC
    is equivalent to S_IXUSR (execute/search permission)

    For example, if  S_IRUSR is specified, then reading is not allowed
    (i.e., the file is write only).  If  S_IWUSR is specified, then writing
    is not allowed (i.e., the file is read only).

Returns:
    The umask function returns the previous value of cmask.

Example:
    #include <sys\types.h>
    #include <sys\stat.h>
    #include <fcntl.h>
    #include <io.h>

    void main()
      {
        int old_mask;

        /* set mask to create read-only files */
        old_mask = umask( S_IWUSR | S_IWGRP | S_IWOTH |
                          S_IXUSR | S_IXGRP | S_IXOTH );
      }

Classification:
    POSIX 1003.1

Systems:
    All, Netware

See Also:
    chmod, creat, mkdir, open, sopen