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@evanharmon
Last active April 12, 2016 00:57
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Simple base server in C
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
/* adapted from http://www.cs.rpi.edu/~moorthy/Courses/os98/Pgms/socket.html */
void error(char *msg) {
perror(msg);
exit(1);
}
int main(int argc, char *argv[]) {
int sockfd, newsockfd, portno, clilen;
char buffer[256];
struct sockaddr_in serv_addr, cli_addr;
int n;
if (argc < 2) {
fprintf(stderr, "Error: no port provided\n");
exit(1);
}
/* first call to socket() */
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
error("Error opening socket");
/* Initialize socket structure */
bzero((char *) &serv_addr, sizeof(serv_addr));
portno = atoi(argv[1]);
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = INADDR_ANY;
serv_addr.sin_port = htons(portno);
/* Bind host address using bind() call */
if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0)
error("Error on binding");
/* Start listening */
listen(sockfd, 5);
socklen_t clilen = sizeof(cli_addr);
/* Accept connection from client */
newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);
if (newsockfd < 0)
error("Error on accept");
/* if connection established, start communicating */
bzero(buffer, 256);
n = read(newsockfd, buffer, 255);
if (n < 0) error("Error reading from socket");
printf("Here is the message: %s\n", buffer);
/* write a response to client */
n = write(newsockfd, "I got your message", 18);
if (n < 0) error("Error writing to socket");
return 0;
}
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