grantpt(3) -- Linux man page
NAMEgrantpt - grant access to the slave pseudotty
#include <stdlib.h> int grantpt(int fd);
DESCRIPTIONThe grantpt() function changes the mode and owner of the slave pseudo-terminal device (pty) corresponding to the master pty referred to by fd. The user ID of the slave is set to the real UID of the calling process. The group ID is set to an unspecified value (e.g. tty). The mode of the slave is set to 0620 (crw--w----).
RETURN VALUEWhen successful, grantpt() returns 0. Otherwise, it returns -1 and sets errno appropriately.
- The fd argument is not a valid open file descriptor.
- The fd argument is valid but not associated with a master pty.
- The corresponding slave pty could not be accessed.
CONFORMING TOPOSIX 1003.1-2001
NOTESThis is part of the Unix98 pty support, see pts(4). Many systems implement this function via a setuid helper binary called "pt_chown". With Linux devpts no such helper binary is required.
SEE ALSOopen(2), getpt(3), ptsname(3), unlockpt(3), pts(4)