Standard C Library: (libc.so, libc.a)
int sockatmark (int socket);
The sockatmark function also supports POSIX.1g Draft 6.6.
Refer to the standards(5) reference page for more information about industry standards and associated tags.
Specifies the file descriptor associated with a socket.
The sockatmark() function enables applications to determine which received data precede the out-of-band data and which data follow the out-of-band data. The function uses the file descriptor for the socket to locate the data. Applications typically use this function between receive operations.
The sockatmark() function does not remove the mark from the stream.
Upon successful completion, the sockatmark() function returns 1 if the protocol has marked the data stream and all data preceding the mark have been read, or 0 (zero) if there is no mark or if data precede the mark in the receive queue.
If the sockatmark() function fails, a value of -1 is returned and errno is set to indicate the error.
If the sockatmark() function fails, errno may be set to one of the following values: The socket parameter is not a valid file descriptor. The socket parameter does not specify a descriptor for a socket.
Functions: recv(2), recvmsg(2).
Standards: standards(5). delim off