TIOCEXCL, TIOCGEXCL, TIOCNXCL - exclusive mode

TIOCEXCL
              Put  the  terminal  into  exclusive  mode.   No  further  open(2)  operations  on the terminal are
              permitted.  (They fail with EBUSY, except for a process with the CAP_SYS_ADMIN capability.)

       TIOCGEXCL
              If the terminal is currently in exclusive mode, place a nonzero value in the location  pointed  to
              by argp; otherwise, place zero in *argp.

       TIOCNXCL
              Disable exclusive mode.

TIOCGEXCL
              Linux 3.8.

       Standard C library (libc, -lc)

       TIOCEXCL, TIOCGEXCL, TIOCNXCL - exclusive mode

       On success, 0 is returned.  On error, -1 is returned, and errno is set to indicate the error.

ioctl(2), ioctl_tty(2)

Linux man-pages 6.9.1                              2024-06-13                                   TIOCEXCL(2const)

#include<asm/termbits.h>  /* Definition of TIOC*XCL constants */
       #include<sys/ioctl.h>intioctl(intfd,TIOCEXCL);intioctl(intfd,TIOCGEXCL,int*argp);intioctl(intfd,TIOCNXCL);