TTYNAME(3) | FreeBSD Library Functions Manual | TTYNAME(3) |
NAME
ttyname, ttyname_r, isatty — get name of associated terminal (tty) from file descriptorLIBRARY
Standard C Library (libc, -lc)SYNOPSIS
#include < unistd.h> char *
ttyname( int fd);
int
ttyname_r( int fd, char *buf, size_t len);
int
isatty( int fd);
DESCRIPTION
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 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
The ttyname_r() may fail and return the following error codes:- [ ENOTTY]
- The fd argument is not a valid file descriptor.
- [ ERANGE]
- The bufsize argument is smaller than the length of the string to be returned.
HISTORY
The isatty() and ttyname() functions appeared in Version 7 AT&T UNIX. The ttyname_r() function appeared in FreeBSD 6.0.May 14, 2005 | FreeBSD |