Chapter 15. Advanced Interprocess Communication

	Example	Relevant Functions
15.1	A program to drive the add2 filter (14.8) (But this time: using a stream pipe)	signal, s_pipe, fork, close, fgets, fputs, strlen, write, read, err_msg, err_sys, err_quit (Stevens' lib), ferror, dup2, printf, execl,
15.2	s_pipe: Create a full-duplex pipe SVR4 Version (Using pipe(2))	pipe
15.3	s_pipe: Create a full-duplex pipe SunOs/BSD version (Using socketpair(3N))	socketpair
15.4	send_err: Send an error message across a stream pipe followed by a status byte	strlen, writen (Stevens' lib), send_fd (Stevens' lib)
15.5	send_fd (SVR4 version) : Send a file-descriptor via a pipe.	write, ioctl
15.6	recv_fd (SVR4 version) : Receive a file descriptor from another process via a pipe. To work with send_fd	getmsg, err_ret (Stevens' lib), err_dump (Stevens' lib), err_sys (Stevens' lib), ioctl
15.7	send_fd (4.3BSD/SunOs Version) : Send a file-descriptor via a pipe	sendmsg
15.8	recv_fd (4.3BSD/SunOs version) : Receive a file descriptor from another process via a pipe. To work with send_fd.	recvmsg, err_ret (Stevens' lib), err_dump (Stevens' lib), err_sys (Stevens' lib)
15.9	send_fd (4.3BSD Reno/4.4BSD Version) : Send a file-descriptor via a pipe.	malloc, sendmsg
15.10	recv_fd (4.3BSD Reno/4.4BSD version) : Receive a file descriptor from another process via a pipe. To work with send_fd.	malloc, recvmsg, err_ret (Stevens' lib), err_dump (Stevens' lib), err_sys (Stevens' lib)
15.11	The open.h header: Interface to a general Client/Server remote file open	csopen: Client/Server open (Stevens' library function)
15.12	Remote get file: a client program that: Reads file names from stdin, Gets them from the remote server, and Prints them to stdout.	fgets, read, write, close, csopen, err_sys (Stevens' lib)
15.13	csopen: Client/Server open (Stevens' library function) Client: open a remote file by sending the server a filename and oflag. Then, reading back an (open) file descriptor.	s_pipe, err_sys (Stevens' lib), fork, close, dup2, execl, sprintf, writev
15.14	The opend.h header file Client/Server indirect open file. Server side types/prototypes declarations	Functions appear below
15.15	main server side function Reads client requests from stream pipe (stdin) and calls the request function to serve it	read, exit, err_sys (Stevens' lib), request (Stevens' func)
15.16	request The routine that does all the real work: Parses client arguments (the request) Opens the file, Sends descriptor back. Sends back errors if there are any problems.	buf_args (Stevens' func), cli_args (Stevens' func), send_err (Stevens' func),
15.17	The buf_args function Parse client request arguments, set options.	strtok, cli_args (Stevens' func. Indirect call)
15.18	The cli_args function Process client request arguments that were prepared by buf_args: Set the options.	strcmp, strcpy, atoi
15.19	serv_listen SVR4 version Unrelated Client/Server (e.g. no parent/child) Server: create a named end connection for a service.	unlink, creat, close, pipe, ioctl, fattach
15.20	serv_accept SVR4 version Unrelated Client/Server (e.g. no parent/child) Server: wait for a client connection to arrive and accept it. Also obtain client's user id.	ioctl
15.21	cli_conn SVR4 version Unrelated Client/Server (e.g. no parent/child) Client: create client endpoint + connect to server.	open, isastream
15.22	serv_listen 4.3BSD/SunOs version (use Unix domain sockets instead of streams) Unrelated Client/Server (e.g. no parent/child) Server: create a named end connection for a service.	socket, unlink, memset strcpy, strlen, bind, listen
15.23	cli_conn 4.3BSD/SunOs version Unrelated Client/Server (e.g. no parent/child) Client: create client endpoint + connect to server.	socket, memset, sprintf, getpid, strlen, err_quit (Stevens' lib), unlink, bind, chmod strcpy, connect,
15.24	serv_accept 4.3BSD/SunOs version Unrelated Client/Server (e.g. no parent/child) Server: wait for a client connection to arrive and accept it. Also obtain client's user id.	accept, stat, time, unlink
15.25	csopen: Revisit: Client/Server remote file open. (A more efficient implementation.) One server handles multiple clients (save fork/exec).	cli_conn (Stevens' func.), err_sys (Stevens' lib), sprintf, strlen, writev recv_fd
15.26	The opend.h header file Server side types/prototypes declarations (for the more efficient implementation.)	cli_args (Stevens' func.) client_add (Stevens' func.), client_del (Stevens' func.), loop (Stevens' func.), request
15.27	client.c: functions to manipulate client array in Server client_add, client_del (for the more efficient implementation.)	malloc, realloc, err_sys (Stevens' lib),
15.28	Main server function Server main (for more efficient implementation.) Loop on clients' requests and serve them -d option for debugging (running interactively rather than as a daemon.)	getopt, err_quit (Stevens' lib), daemon_init (see 13.1), loop
15.29	loop (Version 1): The Server loop function Version 1: using select (Should work on every modern UNIX)	select, read, close, serv_listen (Stevens' func), serv_accept (Stevens' func), log_sys (Stevens' lib), log_msg (Stevens' lib), client_add (Stevens' func), client_del (Stevens' func), request (Stevens' func)
15.30	loop (Version 2): The Server loop function Version 2: using poll POLLIN indicating new client request POLLHUP indicating client termination (SVR4 only)	read, malloc, close, err_sys (Stevens' lib), log_sys (Stevens' lib), log_msg (Stevens' lib), serv_listen (Stevens' func), serv_accept (Stevens' func), client_add (Stevens' func), client_del (Stevens' func), request (Stevens' func) poll
15.31	request: Server side handle request. (for both 4.3BSD/SunOs or SVR4 versions)	open, sprintf, log_sys (Stevens' lib), log_msg (Stevens' lib), buf_args (Stevens' func), cli_args (Stevens' func.) send_err (Stevens' func), send_fd (Stevens' lib), close,