几个简单的Linux下服务器代码

#include <stdio.h> #include <string.h> #include <stdlib.h> #include <unistd.h> #include <ctype.h> #include <sys/socket.h> #include <arpa/inet.h> #include "iolib.h" #define MAX_LINE 100 void my_fun(char * p) { if(p == NULL) /* 空串 */ return; for (; *p != '\0'; p++) if(*p >= 'A'&& *p <= 'Z') *p = *p -'A'+ 'a'; } int main(void) { struct sockaddr_in sin; struct sockaddr_in cin; int l_fd; int c_fd; socklen_t len; char buf[MAX_LINE]; char addr_p[INET_ADDRSTRLEN]; int port = 8000; int n; bzero(&sin, sizeof(sin)); sin.sin_family = AF_INET; sin.sin_addr.s_addr = INADDR_ANY; sin.sin_port = htons(port); if( (l_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1){ perror("fail to creat socket"); exit(1); } if(bind(l_fd, (struct sockaddr *) &sin, sizeof(sin)) == -1){ perror("fail to bind"); exit(1); } if(listen(l_fd, 10) == -1){ perror("fail to listen"); exit(1); } printf("waiting ...\n"); while(1){ if( (c_fd = accept(l_fd, (struct sockaddr *) &cin, &len)) == -1){ perror("fail to accept"); exit(1); } n = my_read(c_fd, buf, MAX_LINE); if(n == -1) exit(1); else if(n == 0){ printf("the connect has been closed\n"); close(c_fd); continue; } inet_ntop(AF_INET, &cin.sin_addr, addr_p, sizeof(addr_p)); printf("client IP is %s, port is %d\n", addr_p, ntohs(cin.sin_port)); printf("content is : %s\n", buf); my_fun(buf); n = my_write(c_fd, buf, n); if(n == -1){ exit(1); } if(close(c_fd) == -1){ perror("fail to close"); exit(1); } } if(close(l_fd) == -1){ perror("fail to close"); exit(1); } return 0; }