June 4, 1993 CTERMID 3

### NAME

ctermid - generate terminal pathname

### LIBRARY

Standard C Library (libc, -lc)

### SYNOPSIS

```char``*` ctermid(```char *buf`)

### DESCRIPTION

The ctermid(``) function generates a string, that, when used as a pathname, refers to the current controlling terminal of the calling process.

If buf is the ```NULL` pointer, a pointer to a static area is returned. Otherwise, the pathname is copied into the memory referenced by buf. The argument buf is assumed to point to an array at least ```L_ctermid` bytes long (as defined in the include file <```stdio.h`>).

The current implementation simply returns `/dev/tty'.

### RETURN VALUES

Upon successful completion, a non-```NULL` pointer is returned. Otherwise, a ```NULL` pointer is returned and the global variable errno is set to indicate the error.

### ERRORS

The current implementation detects no error conditions.

### SEE ALSO

ttyname(3)

### STANDARDS

The ctermid(``) function conforms to ISO/IEC 9945-1:1990 (``POSIX.1'') .

### BUGS

By default the ctermid(``) function writes all information to an internal static object. Subsequent calls to ctermid(``) will modify the same object.