unlockpt(3C)                     UNIX System V                     unlockpt(3C)


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

SYNOPSIS
      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) in the Programmer's Guide: STREAMS

































10/89                                                                    Page 1