SETMODE(3)             FreeBSD Library Functions Manual             SETMODE(3)

NAME
     getmode, setmode - modify mode bits

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

     mode_t
     getmode(const void *set, mode_t mode);

     void *
     setmode(const char *mode_str);

DESCRIPTION
     The getmode() function returns a copy of the file permission bits mode as
     altered by the values pointed to by set.  While only the mode bits are
     altered, other parts of the file mode may be examined.

     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().

ERRORS
     The setmode() function may fail and set errno for any of the errors
     specified for the library routine malloc(3) or strtol(3).  In addition,
     setmode() will fail and set errno to:

     [EINVAL]           The mode argument does not represent a valid mode.

SEE ALSO
     chmod(1), stat(2), umask(2), malloc(3)

HISTORY
     The getmode() and setmode() functions first appeared in 4.4BSD.

BUGS
     The setmode() function is not thread safe.  Files created in other
     threads while setmode() is being called may be created with a umask of 0.

FreeBSD 13.1-RELEASE-p6          July 18, 2019         FreeBSD 13.1-RELEASE-p6