- "Return data from the socket port @var{sock} and also\n"
- "information about where the data was received from.\n"
- "@var{sock} must already be bound to the address from which\n"
- "data is to be received. @code{str}, is a string into which the\n"
- "data will be written. The size of @var{str} limits the amount\n"
- "of data which can be received: in the case of packet protocols,\n"
- "if a packet larger than this limit is encountered then some\n"
- "data will be irrevocably lost.\n\n"
- "The optional @var{flags} argument is a value or bitwise OR of\n"
- "@code{MSG_OOB}, @code{MSG_PEEK}, @code{MSG_DONTROUTE} etc.\n\n"
- "The value returned is a pair: the @emph{car} is the number of\n"
- "bytes read from the socket and the @emph{cdr} an address object\n"
- "in the same form as returned by @code{accept}. The address\n"
- "will given as @code{#f} if not available, as is usually the\n"
- "case for stream sockets.\n\n"
- "The @var{start} and @var{end} arguments specify a substring of\n"
- "@var{str} to which the data should be written.\n\n"
- "Note that the data is read directly from the socket file\n"
- "descriptor: any unread buffered port data is ignored.")
+ "Receive data from socket port @var{sock} (which must be already\n"
+ "bound), returning the originating address as well as the data.\n"
+ "This is usually for use on datagram sockets, but can be used on\n"
+ "stream-oriented sockets too.\n"
+ "\n"
+ "The data received is stored in the given @var{str}, using\n"
+ "either the whole string or just the region between the optional\n"
+ "@var{start} and @var{end} positions. The size of @var{str}\n"
+ "limits the amount of data which can be received. For datagram\n"
+ "protocols, if a packet larger than this is received then excess\n"
+ "bytes are irrevocably lost.\n"
+ "\n"
+ "The return value is a pair. The @code{car} is the number of\n"
+ "bytes read. The @code{cdr} is a socket address object which is\n"
+ "where the data come from, or @code{#f} if the origin is\n"
+ "unknown.\n"
+ "\n"
+ "The optional @var{flags} argument is a or bitwise OR\n"
+ "(@code{logior}) of @code{MSG_OOB}, @code{MSG_PEEK},\n"
+ "@code{MSG_DONTROUTE} etc.\n"
+ "\n"
+ "Data is read directly from the socket file descriptor, any\n"
+ "buffered port data is ignored.\n"
+ "\n"
+ "On a GNU/Linux system @code{recvfrom!} is not multi-threading,\n"
+ "all threads stop while a @code{recvfrom!} call is in progress.\n"
+ "An application may need to use @code{select}, @code{O_NONBLOCK}\n"
+ "or @code{MSG_DONTWAIT} to avoid this.")