'\" et
.TH PTSNAME "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.SH PROLOG
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.
.\"
.SH NAME
ptsname
\(em get name of the slave pseudo-terminal device
.SH SYNOPSIS
.LP
.nf
#include <stdlib.h>
.P
char *ptsname(int \fIfildes\fP);
.fi
.SH DESCRIPTION
The
\fIptsname\fR()
function shall return the name of the slave pseudo-terminal device
associated with a master pseudo-terminal device. The
.IR fildes
argument is a file descriptor that refers to the master device. The
\fIptsname\fR()
function shall return a pointer to a string containing the pathname
of the corresponding slave device.
.P
The
\fIptsname\fR()
function need not be thread-safe.
.SH "RETURN VALUE"
Upon successful completion,
\fIptsname\fR()
shall return a pointer to a string which is the name of the
pseudo-terminal slave device. Upon failure,
\fIptsname\fR()
shall return a null pointer and may set
.IR errno .
This could occur if
.IR fildes
is an invalid file descriptor or if the slave device name does not
exist in the file system.
.P
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
\fIptsname\fR().
The returned pointer and the string content might also be invalidated
if the calling thread is terminated.
.SH ERRORS
The
\fIptsname\fR()
function may fail if:
.TP
.BR EBADF
The
.IR fildes
argument is not a valid file descriptor.
.TP
.BR ENOTTY
The file associated with the
.IR fildes
argument is not a master pseudo-terminal device.
.LP
.IR "The following sections are informative."
.SH EXAMPLES
None.
.SH "APPLICATION USAGE"
None.
.SH RATIONALE
See the RATIONALE section for
.IR "\fIposix_openpt\fR\^(\|)".
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.IR "\fIgrantpt\fR\^(\|)",
.IR "\fIopen\fR\^(\|)",
.IR "\fIposix_openpt\fR\^(\|)",
.IR "\fIttyname\fR\^(\|)",
.IR "\fIunlockpt\fR\^(\|)"
.P
The Base Definitions volume of POSIX.1\(hy2017,
.IR "\fB<stdlib.h>\fP"
.\"
.SH COPYRIGHT
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 .
.PP
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 .