| 
SOCKATMARK(3) | 
Library Functions Manual | 
SOCKATMARK(3) | 
NAME
 sockatmark — determine whether a socket is at the out-of-band mark
LIBRARY
 Standard C Library (libc, -lc)
DESCRIPTION
 The sockatmark function determines whether the socket referenced by the file descriptor s is at the out-of-band mark.
RETURN VALUES
 If successful, the sockatmark function returns 1 to indicate that the socket is at an out-of-band mark; 0 is returned if there is no out-of-band mark or the mark is preceded by in-band data. Otherwise, -1 is returned and errno is set to indicate the error.
ERRORS
 The 
sockatmark function will fail if:
- 
[EBADF]
 
- 
The argument s is not a valid file descriptor.
 
- 
[ENOTTY]
 
- 
The file descriptor s does not refer to a socket.
 
 
SEE ALSO
 ioctl(2), 
recv(2), 
socket(2)
Stuart Sechrest, An Introductory 4.4BSD Interprocess Communication Tutorial. (see /usr/share/doc/psd/20.ipctut)
Samuel J. Leffler, Robert S. Fabry, William N. Joy, Phil Lapsley, Steve Miller, and Chris Torek, Advanced 4.4BSD IPC Tutorial. (see /usr/share/doc/psd/21.ipc)
 
STANDARDS
 The sockatmark function conforms to IEEE Std 1003.1-2001 (“POSIX.1”).
HISTORY
 The 
sockatmark function appeared in IEEE Std 1003.1g-2000 (“POSIX.1”) as a replacement for the 
SIOCATMARK ioctl(2) interface.