unlockpt — unlock a pseudo-terminal manager/subsidiary pair
The unlockpt() function shall unlock the subsidiary pseudo-terminal device associated with the manager device to which fildes refers.
Conforming applications shall ensure that they call unlockpt() before opening the subsidiary side of a pseudo-terminal device.
Upon successful completion, unlockpt() shall return 0. Otherwise, it shall return -1 and set errno to indicate the error.
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 manager pseudo-terminal device.
None.
None.
See the RATIONALE section for posix_openpt .
None.
grantpt , open , posix_openpt , ptsname
XBD <stdlib.h>
First released in Issue 4, Version 2.
Moved from X/OPEN UNIX extension to BASE.
The normative text is updated to avoid use of the term "must" for application requirements.
POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0697 [96] is applied.
Austin Group Defect 1466 is applied, changing the terminology used for pseudo-terminal devices.
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