This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.
#include <stdlib.h> char *ptsname(int fildes);
The ptsname() function shall return the name of the slave pseudo-terminal device associated with a master pseudo-terminal device. The fildes argument is a file descriptor that refers to the master device. The ptsname() function shall return a pointer to a string containing the pathname of the corresponding slave device.
The ptsname() function need not be thread-safe.
Upon successful completion, ptsname() shall return a pointer to a string which is the name of the pseudo-terminal slave device. Upon failure, ptsname() shall return a null pointer and may set errno. This could occur if fildes is an invalid file descriptor or if the slave device name does not exist in the file system.
The application shall not modify the string returned. The returned pointer might be invalidated or the string content might be overwritten by a subsequent call to ptsname(). The returned pointer and the string content might also be invalidated if the calling thread is terminated.
The ptsname() function may fail if:
The fildes argument is not a valid file descriptor.
The file associated with the fildes argument is not a master pseudo-terminal device.
The following sections are informative.
See the RATIONALE section for posix_openpt().
grantpt(), open(), posix_openpt(), ttyname(), unlockpt()
The Base Definitions volume of POSIX.1-2017, <stdlib.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .
Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .
grantpt(3p), posix_openpt(3p), stdlib.h(0p), unlockpt(3p).