tcp-udp.rar_tcp

#include <stdio.h> #include <string.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <fcntl.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #define MAXLINE 1024 void usage(char *command) { printf("usage :%s <portnum>", command); exit(0); } int main(int argc,char **argv) { struct sockaddr_in serv_addr; struct sockaddr_in clie_addr; char buf[MAXLINE]; int sock_id; int link_id; int recv_len; int read_len; int send_len; int clie_addr_len; int filesize; int fp; if (argc != 2) { usage(argv[0]); } /*if ((fp = fopen(argv[2], "r")) == NULL) { perror("The file does not exist!\n"); exit(0); }*/ if ((sock_id = socket(AF_INET, SOCK_STREAM, 0)) < 0) { perror("Create socket failed\n"); exit(0); } memset(&serv_addr, 0, sizeof(serv_addr)); serv_addr.sin_family = AF_INET; serv_addr.sin_port = htons(atoi(argv[1])); serv_addr.sin_addr.s_addr = htonl(INADDR_ANY); if (bind(sock_id, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0 ) { perror("Bind socket failed\n"); exit(0); } while (1) { if ((listen(sock_id, 10))!=0) { perror("Listen socket failed\n"); exit(0); } link_id=accept(sock_id,NULL,NULL); if (-1 == link_id) { perror("Accept socket failed\n"); exit(0); } clie_addr_len = sizeof(clie_addr); if ((recv_len = recv(link_id, buf, MAXLINE, 0))== -1){ printf("recv() failed\n"); } buf[recv_len]='\0'; if((fp=open(buf,O_RDWR))==-1){ printf("File does not exist\n"); char NullRe[4]={'N','U','L','L'}; send(link_id,NullRe,4,0); } filesize=lseek(fp,0,SEEK_END); lseek(fp,0,SEEK_SET); char fileSe[filesize]; if(read(fp,fileSe,filesize)<=0){ printf("read error\n"); exit(0); } if(send(link_id,fileSe,filesize,0)<=0){ printf("send failed\n"); exit(0); } } printf("\nSend Finish\n"); close(sock_id); close(link_id); return 0; }