umask(2) - NetBSD Manual Pages

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UMASK(2)                  NetBSD Programmer's Manual                  UMASK(2)


NAME

     umask - set file creation mode mask


SYNOPSIS

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

     mode_t
     umask(mode_t numask);


DESCRIPTION

     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 per-
     mission bits of numask are used by system calls, including open(2),
     mkdir(2),  mkfifo(2) and mknod(2) to turn off corresponding bits request-
     ed in file mode.  (See chmod(2)).  This clearing allows each user to re-
     strict the default access to his files.

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


RETURN VALUES

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


ERRORS

     The umask() function is always successful.


SEE ALSO

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


STANDARDS

     The umask() function conforms to IEEE Std1003.1-1990 (``POSIX'').

4th Berkeley Distribution        June 4, 1993                                1