NAME    [Toc]    [Back]

     umask - set file creation mode mask

LIBRARY    [Toc]    [Back]

     Standard C Library (libc, -lc)

SYNOPSIS    [Toc]    [Back]

     #include <sys/stat.h>

     mode_t
     umask(mode_t numask);

DESCRIPTION    [Toc]    [Back]

     The umask() routine sets the process's file mode creation mask to numask
     and returns the previous value of the mask.  The 9 low-order access permission
 bits of numask are used by system calls, including open(2),
     mkdir(2), mkfifo(2) and mknod(2) to turn off corresponding bits requested
     in file mode.  (See chmod(2)).  This clearing allows each user to
     restrict the default access to his files.

     The default mask value is S_IWGRP|S_IWOTH (022, write access for the
     owner only).  Child processes inherit the mask of the calling process.

RETURN VALUES    [Toc]    [Back]

     The previous value of the file mode mask is returned by the call.

ERRORS    [Toc]    [Back]

     The umask() function is always successful.

SEE ALSO    [Toc]    [Back]

     chmod(2), mkdir(2), mkfifo(2), mknod(2), open(2)

STANDARDS    [Toc]    [Back]

     The umask() function conforms to ISO/IEC 9945-1:1990 (``POSIX.1'').

BSD                              June 4, 1993                              BSD