ttyname3
Get name of associated terminal (tty) from file descriptor
Usage
#include <unistd.h>
char *
ttyname(int fd);
int
ttyname_r(int fd, char *buf, size_t len);
int
isatty(int fd);
Library
Standard C Library (libc, -lc)
Overview
These functions operate on file descriptors for terminal type devices.
The isatty() function determines if the file descriptor fd refers to a valid terminal type device.
The ttyname() function gets the related device name of a file descriptor for which isatty() is true.
The ttyname() function returns the name stored in a static buffer which will be overwritten on subsequent calls. The ttyname_r() function takes a buffer and length as arguments to avoid this problem.
Return values
The isatty() function returns 1 if fd refers to a terminal type device; otherwise, it returns 0 and may set errno to indicate the error. The ttyname() function returns the null terminated name if the device is found and isatty() is true; otherwise a NULL pointer is returned. The ttyname_r() function returns 0 if successful. Otherwise an error number is returned.
Errors
These functions may fail if:
- [EBADF]
-
The fd argument is not a valid file descriptor.
- [ENOTTY]
-
The file associated with fd is not a terminal.
Additionally, ttyname_r() may fail if:
- [ERANGE]
-
The bufsize argument is smaller than the length of the string to be returned.
Releases
87 releases since FreeBSD 2.0.5-RELEASE; the text changed 42 times.