|GRANTPT(3)||Linux Programmer's Manual||GRANTPT(3)|
int grantpt(int fd);
Glibc 2.23 and earlier: _XOPEN_SOURCE
The behavior of grantpt() is unspecified if a signal handler is installed to catch SIGCHLD signals.
- The corresponding slave pseudoterminal could not be accessed.
- The fd argument is not a valid open file descriptor.
- The fd argument is valid but not associated with a master pseudoterminal.
|grantpt ()||Thread safety||MT-Safe locale|
Many systems implement this function via a set-user-ID helper binary called "pt_chown". On Linux systems with a devpts filesystem (present since Linux 2.2), the kernel normally sets the correct ownership and permissions for the pseudoterminal slave when the master is opened (posix_openpt(3)), so that nothing must be done by grantpt(). Thus, no such helper binary is required (and indeed it is configured to be absent during the glibc build that is typical on many systems).