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(#)socketpair.c 8.1 (Berkeley) 6/8/93
30 #include <sys/types.h>
31 #include <sys/socket.h>
34 #define DATA1 "In Xanadu, did Kublai Khan . . ."
35 #define DATA2 "A stately pleasure dome decree . . ."
38 * This program creates a pair of connected sockets then forks and
39 * communicates over them. This is very similar to communication with pipes,
40 * however, socketpairs are two-way communications objects. Therefore I can
41 * send messages in both directions.
46 int sockets
[2], child
;
49 if (socketpair(AF_UNIX
, SOCK_STREAM
, 0, sockets
) < 0) {
50 perror("opening stream socket pair");
54 if ((child
= fork()) == -1)
56 else if (child
) { /* This is the parent. */
58 if (read(sockets
[1], buf
, 1024, 0) < 0)
59 perror("reading stream message");
60 printf("-->%s\en", buf
);
61 if (write(sockets
[1], DATA2
, sizeof(DATA2
)) < 0)
62 perror("writing stream message");
64 } else { /* This is the child. */
66 if (write(sockets
[0], DATA1
, sizeof(DATA1
)) < 0)
67 perror("writing stream message");
68 if (read(sockets
[0], buf
, 1024, 0) < 0)
69 perror("reading stream message");
70 printf("-->%s\en", buf
);