Manual Pages  — SETMODE

The setmode() function takes an absolute (octal) or symbolic value, as described in chmod(1), as an argument and returns a pointer to mode values to be supplied to getmode(). Because some of the symbolic values are relative to the file creation mask, setmode() may call umask(2). If this occurs, the file creation mask will be restored before setmode() returns. If the calling program changes the value of its file creation mask after calling setmode(), setmode() must be called again if getmode() is to modify future file modes correctly.

If the mode passed to setmode() is invalid or if memory cannot be allocated for the return value, setmode() returns NULL.

The value returned from setmode() is obtained from malloc() and should be returned to the system with free() when the program is done with it, generally after a call to getmode().