unlockpt(3C)

NAME
     unlockpt - unlock a pseudo-terminal master/slave pair

SYNOPSIS
     #include <stdlib.h>

     int unlockpt(int fildes);

DESCRIPTION
     The function unlockpt() clears a lock flag associated with the slave
     pseudo-terminal device associated with its master pseudo-terminal
     counterpart so that the slave pseudo-terminal device can be opened.
     fildes is a file descriptor returned from a successful open of a master
     pseudo-terminal device.

RETURN VALUE
     Upon successful completion, the function unlockpt() returns 0; otherwise
     it returns -1. A failure may occur if fildes is not an open file
     descriptor or is not associated with a master pseudo-terminal device.

SEE ALSO
     open(2), grantpt(3C), ptsname(3C)