NAME | SYNOPSIS | FEATURES | DESCRIPTION | PARAMETERS | RETURN VALUES | ERRORS | ATTRIBUTES | SEE ALSO
#include <sys/stat.h>mode_t umask(mode_t numask);
MSDOSFS, NFS_CLIENT, UFS
umask() sets the file mode creation mask for a process to numask and returns the previous value of the mask. The nine low-order access permission bits of numask are used by system calls, including mkdir(2POSIX), mkfifo(2POSIX) and open(2POSIX), to turn off corresponding bits requested in file mode. See chmod(2POSIX). This clearing allows users to restrict the default access to their own files.
The default mask value is S_IWGRP|S_IWOTH, or 022, providing write access for the owner only. Child processes inherit the mask of the calling process.
umask() takes the parameter numask, which defines access permission bits.
The previous value of the file mode mask is returned by the call.
The umask() function is always successful.
See attributes(5) for descriptions of the following attributes:
ATTRIBUTE TYPE | ATTRIBUTE VALUE |
---|---|
Interface Stability | Evolving |
NAME | SYNOPSIS | FEATURES | DESCRIPTION | PARAMETERS | RETURN VALUES | ERRORS | ATTRIBUTES | SEE ALSO