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ctermid, ctermid_r - generate path name for controlling terminal


#include <stdio.h>

char *ctermid(char *s);

char *ctermid_r(char *s);


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>.

The ctermid_r() function behaves as ctermid() except that if s is a null pointer, the function returns NULL.


The difference between ctermid() and ttyname(3C) is that ttyname() must be passed a file descriptor and returns the actual name of the terminal 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.


See attributes(7) for descriptions of the following attributes:


ttyname(3C), attributes(7)

solaris/ctermid.3c.txt · Last modified: 2023/07/19 08:58 by A User Not Logged in