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#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#include <string.h>
#include <arpa/inet.h>
#include <wait.h>
int main(int argc, char *argv[]) {
int sockfd, connfd;
struct sockaddr_in servaddr, cli;
sockfd = socket(AF_INET, SOCK_STREAM, 0);
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
int port = atoi(argv[1]);
servaddr.sin_port = htons(port);
bind(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
listen(sockfd, 128);
printf("Server started at %s...\n", inet_ntoa(servaddr.sin_addr));
fflush(stdout);
while(1) {
socklen_t len = sizeof(cli);
connfd = accept(sockfd, (struct sockaddr *)&cli, &len);
int i = getpeername(connfd, (struct sockaddr*)&cli, &len);
printf("Client connected at port %d\n", htons(cli.sin_port));
int n;
char buf[100];
int pid;
if((pid=fork())==0){
close(sockfd);
while((n = recv(connfd, buf, 100, 0)) > 0) {
printf("Client message: %s\n", buf);
int pipes[2];
pipe(&pipes[0]);
if ((pid=fork()) == 0) {
dup2(pipes[1], STDOUT_FILENO);
close(pipes[0]);
execl("/bin/sh", "sh", "-c", buf, (char *) NULL);
} else {
close(pipes[1]);
char cmd_output[1024];
int cmd_size = read(pipes[0], cmd_output, sizeof(cmd_output));
send(connfd, cmd_output, cmd_size, 0);
wait(NULL);
}
fflush(stdout);
};
exit(0);
}
close(connfd);
}
return 0;
}
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