ctermid(3C) Standard C Library Functions ctermid(3C)
NAME
ctermid, ctermid_r - generate path name for controlling terminal
SYNOPSIS
#include <stdio.h>
char *ctermid(char *s);
char *ctermid_r(char *s);
DESCRIPTION
ctermid()
The ctermid() function generates the path name of the controlling terminal for the current process and stores it in a string.
If s is a null pointer, the string is stored in an internal static area whose address is returned and whose contents are overwritten at the
next call to ctermid(). Otherwise, s is assumed to point to a character array of at least L_ctermid elements. The path name is placed in
this array and the value of s is returned. The constant L_ctermid is defined in the header <stdio.h>.
ctermid_r()
The ctermid_r() function behaves as ctermid() except that if s is a null pointer, the function returns NULL.
USAGE
The difference between ctermid() and ttyname(3C) is that ttyname() must be passed a file descriptor and returns the actual name of the ter-
minal associated with that file descriptor, while ctermid() returns a string (/dev/tty) that will refer to the terminal if used as a file
name. The ttyname() function is useful only if the process already has at least one file open to a terminal.
The ctermid() function is unsafe in multithreaded applications. The ctermid_r() function is MT-Safe and should be used instead.
When compiling multithreaded applications, the _REENTRANT flag must be defined on the compile line. This flag should be used only with
multithreaded applications.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |ctermid() is Standard |
+-----------------------------+-----------------------------+
|MT-Level |ctermid() is Unsafe; cter- |
| |mid_r() is MT-Safe |
+-----------------------------+-----------------------------+
SEE ALSO
ttyname(3C), attributes(5)
SunOS 5.10 25 Jul 2000 ctermid(3C)
