Updated: 2022/Sep/29
Please read Privacy Policy. It's for your privacy.
UMASK(2) System Calls Manual UMASK(2) NAME umask - set file creation mode mask LIBRARY Standard C Library (libc, -lc) SYNOPSIS #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 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 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 Std 1003.1-1990 ("POSIX.1"). NetBSD 9.99 June 4, 1993 NetBSD 9.99