unlockpt(3C)

NAME

     unlockpt - unlock a pseudo-terminal master/slave pair

SYNOPSIS

     #include <stdlib.h>

     int unlockpt(int fildes);

DESCRIPTION

     The unlockpt() function unlocks  the  slave  pseudo-terminal
     device associated with the master to which fildes refers.

     Portable applications must call  unlockpt()  before  opening
     the slave side of a pseudo-terminal device.

RETURN VALUES

     Upon successful completion, unlockpt() returns 0. Otherwise,
     it returns -1 and sets errno to indicate the error.

ERRORS

     The unlockpt() function may fail if:

     EBADF The fildes argument is not a file descriptor open  for
           writing.

     EINVAL
           The fildes argument is not associated  with  a  master
           pseudo-terminal device.

ATTRIBUTES

     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | MT-Level                    | Safe                        |
    |_____________________________|_____________________________|

SEE ALSO

     open(2), grantpt(3C), ptsname(3C), attributes(5)

     STREAMS Programming Guide