68 lines
1.6 KiB
C
68 lines
1.6 KiB
C
/* This file is part of the sample code and exercises
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* used by the class "Advanced Programming in the UNIX
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* Environment" taught by Jan Schaumann
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* <jschauma@netmeister.org> at Stevens Institute of
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* Technology.
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*
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* This file is in the public domain.
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*
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* You don't have to, but if you feel like
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* acknowledging where you got this code, you may
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* reference me by name, email address, or point
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* people to the course website:
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* https://stevens.netmeister.org/631/
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*/
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <netdb.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#define PORT 12345
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#define DATA "Just some data"
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int main() {
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int child;
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int sock;
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struct sockaddr_in name;
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char buf[BUFSIZ];
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memset(&name, 0, sizeof(name));
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if ((sock = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
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perror("opening datagram socket");
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exit(EXIT_FAILURE);
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}
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name.sin_family = PF_INET;
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name.sin_addr.s_addr = INADDR_ANY;
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name.sin_port = htons(PORT);
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if ((child = fork()) == -1) {
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perror("fork");
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} else if (child) {
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if (bind(sock, (struct sockaddr *)&name, sizeof(name))) {
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perror("binding name to datagram socket");
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exit(EXIT_FAILURE);
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}
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if (read(sock, buf, BUFSIZ) < 0) {
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perror("reading from socket");
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}
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(void)printf("Parent (%d) --> reading: %s\n", getpid(), buf);
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(void)close(sock);
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} else {
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printf("Child (%d) --> sending...\n", getpid());
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if (sendto(sock, DATA, sizeof(DATA), 0, (struct sockaddr *)&name, sizeof(name)) < 0) {
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perror("sending datagram message");
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}
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(void)close(sock);
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}
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return EXIT_SUCCESS;
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}
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