今天实现的这个服务器程序加入了对多个客户端同时请求处理的实现，服务器端通过对每次监听到的客户端程序新建一个子进程，进行相关的处理，将从客户端传来的字符串数据，转化为大写的字符串序列，然重新写回到connfd；另一方面，客户端通过在标准输入里获取客户输入到的字符串序列，传送到connfd,再从connfd读取经服务器处理过的字符串序列打印到标准输出上。
同时，加上了对某些socket原语函数的封装处理，主要封装了对出错的处理机制，基本原语函数都以相应大写首个字符的命名表示，定义在“wrap.c”和“wrap.h”文件中。
wrap.h
1 /* wrap.h */ 2 #ifndef __WRAP_H_ 3 #define __WRAP_H_ 4 5 void perr_exit(const char *s); 6 int Accept(int fd, struct sockaddr *sa, socklen_t *salenptr); 7 void Bind(int fd, const struct sockaddr *sa, socklen_t salen); 8 void Connect(int fd, const struct sockaddr *sa, socklen_t salen); 9 void Listen(int fd, int backlog); 10 int Socket(int family, int type, int protocol); 11 ssize_t Read(int fd, void *ptr, size_t nbytes); 12 ssize_t Write(int fd, const void *ptr, size_t nbytes); 13 void Close(int fd); 14 ssize_t Readn(int fd, void *vptr, size_t n); 15 ssize_t Writen(int fd, const void *vptr, size_t n); 16 static ssize_t my_read(int fd, char *ptr); 17 ssize_t Readline(int fd, void *vptr, size_t maxlen); 18 19 #endif
wrap.c
1 /*wrap.c */
2 #include<stdlib.h>
3 #include<errno.h>
4 #include<sys/socket.h>
5
6 void perr_exit(const char* s)
7 {
8 perror(s);
9 exit(1);
10 }
11
12 int Accept(int fd,struct sockaddr *sa,socklen_t *salenptr)
13 {
14 int n;
15 again:
16 if((n=accept(fd,sa,salenptr))<0){
17 if((errno==ECONNABORTED)||(errno==EINTR))
18 goto again;
19 else
20 perr_exit("accept error");
21 }
22 return n;
23 }
24
25 void Bind(int fd,const struct sockaddr *sa,socklen_t salen)
26 {
27 if(bind(fd,sa,salen)<0)
28 perr_exit("bind error");
29 }
30
31 void Connect(int fd,const struct sockaddr *sa,socklen_t salen)
32 {
33 if(connect(fd,sa,salen)<0)
34 perr_exit("connect error");
35 }
36
37 void Listen(int fd,int backlog)
38 {
39 if(listen(fd,backlog)<0)
40 perr_exit("listen error");
41 }
42
43 int Socket(int family,int type,int protocol)
44 {
45 int n;
46 if((n=socket(family,type,protocol))<0)
47 perr_exit("socket error");
48 return n;
49 }
50
51 ssize_t Read(int fd,void *ptr,size_t nbytes)
52 {
53 ssize_t n;
54 again:
55 if((n=read(fd,ptr,nbytes))==-1){
56 if(errno==EINTR)
57 goto again;
58 else
59 return -1;
60 }
61 return n;
62 }
63
64 ssize_t Write(int fd,const void *ptr,size_t nbytes)
65 {
66 ssize_t n;
67 again:
68 if((n=write(fd,ptr,nbytes))==-1){
69 if(errno==EINTR)
70 goto again;
71 else
72 return -1;
73 }
74 return n;
75 }
76
77 void Close(int fd)
78 {
79 if(close(fd)==-1)
80 perr_exit("close error");
81 }
82
83 ssize_t Readn(int fd,void *vptr,ssize_t n)
84 {
85 size_t nleft;
86 ssize_t nread;
87 char *ptr;
88 ptr=vptr;
89 nleft=n;
90 while(nleft>0){
91 if((nread=read(fd,ptr,nleft))<0){
92 if(errno==EINTR)
93 nread=0;
94 else
95 return -1;
96 }else if(nread==0)
97 break;
98 nleft-=nread;
99 ptr+=nread;
100 }
101 return n-nleft;
102 }
103
104
105 ssize_t Writen(int fd,const void *vptr,size_t n)
106 {
107 size_t nleft;
108 ssize_t nwritten;
109 const char* ptr;
110 ptr=vptr;
111 nleft=n;
112 while(nleft>0){
113 if(nwritten=write(fd,ptr,nleft)<=0){
114 if(nwritten<0&&errno==EINTR)
115 nwritten=0;
116 else
117 return -1;
118 }
119 nleft-=nwritten;
120 ptr+=nwritten;
121 }
122 return n;
123 }
124
125 static ssize_t my_read(int fd,char* ptr)
126 {
127 static int read_cnt;
128 static char *read_ptr;
129 static char read_buf[100];
130 if(read_cnt<=0){
131 again:
132 if((read_cnt=read(fd,read_buf,sizeof(read_buf)))<0){
133 if(errno==EINTR)
134 goto again;
135 else
136 return -1;
137 }else if(read_cnt==0)
138 return 0;
139 read_ptr=read_buf;
140 }
141 read_cnt--;
142 *ptr=*read_ptr++;
143 return 1;
144 }
145
146 ssize_t Readline(int fd,void *vptr,size_t maxlen)
147 {
148 ssize_t n,rc;
149 char c,*ptr;
150 ptr=vptr;
151 for(n=1;n<maxlen;n++){
152 if((rc=my_read(fd,&c))==1){
153 *ptr++=c;
154 if(c==‘\n‘)
155 break;
156 }else if(rc==0){
157 *ptr=0;
158 return n-1;
159 }else
160 return -1;
161 }
162 *ptr=0;
163 return n;
164 }
165
服务器端：
1 #include<stdlib.h>
2 #include<stdio.h>
3 #include<unistd.h>
4 #include<string.h>
5 #include<netinet/in.h>
6 #include<sys/types.h>
7 #include<sys/socket.h>
8 #include<arpa/inet.h>
9 #include "wrap.c"
10 #define SERVER_PORT 8000
11 #define BUFSIZE 80
12 int main(int argc,char* argv[])
13 {
14 struct sockaddr_in serveraddr,clientaddr;
15 int listenfd,connfd,len,clientaddr_len,i;
16 char buf[BUFSIZE];
17 char str[BUFSIZE];
18 pid_t pid;
19 listenfd=Socket(AF_INET,SOCK_STREAM,0);
20
21 bzero(&serveraddr,sizeof(serveraddr));
22 serveraddr.sin_family=AF_INET;
23 serveraddr.sin_addr.s_addr=htonl(INADDR_ANY);
24 serveraddr.sin_port=htons(SERVER_PORT);
25
26 Bind(listenfd,(struct sockaddr *)&serveraddr,sizeof(serveraddr));
27
28 Listen(listenfd,128);
29 printf("waiting for connecting\n");
30 while(1){
31 clientaddr_len=sizeof(clientaddr);
32 connfd=Accept(listenfd,(struct sockaddr *)&clientaddr,&clientaddr_len);
33 printf("client ip: %s\tport :%d\n",inet_ntop(AF_INET,&clientaddr.sin_addr.s_addr,str,sizeof(str)),ntohs(clientaddr.sin_port));
34 pid=fork();
35 if(pid==0){
36 Close(listenfd);
37 while(1){
38 len=Read(connfd,buf,sizeof(buf));
39 for(i=0;i<len;i++)
40 buf[i]=toupper(buf[i]);
41 Write(connfd,buf,len);
42 }
43 Close(connfd);
44 return 0;
45 }else if(pid>0){
46 Close(connfd);
47 }
48 else{
49 //error deal
50 }
51 }
52 // Close(listenfd);
53 return 0;
54 }
客户端：
1 #include<stdlib.h>
2 #include<stdio.h>
3 #include<string.h>
4 #include<sys/types.h>
5 #include<netinet/in.h>
6 #include<sys/socket.h>
7 #include<unistd.h>
8 #include "wrap.c"
9 #define SERVER_PORT 8000
10 #define BUFSIZE 80
11 int main(int argc,char* argv[])
12 {
13 int confd,len;
14 struct sockaddr_in serveraddr;
15 confd=Socket(AF_INET,SOCK_STREAM,0);
16 char buf[BUFSIZE];
17
18 bzero(&serveraddr,sizeof(serveraddr));
19 serveraddr.sin_family=AF_INET;
20 inet_pton(AF_INET,"127.0.0.1",&serveraddr.sin_addr.s_addr);
21 serveraddr.sin_port=htons(SERVER_PORT);
22
23 Connect(confd,(struct sockaddr*)&serveraddr,sizeof(serveraddr));
24 while(fgets(buf,sizeof(buf),stdin)){
25 Write(confd,buf,strlen(buf));
26 len=Read(confd,buf,BUFSIZE);
27 printf("the result from server:\n");
28 Write(STDOUT_FILENO,buf,len);
29 }
30
31 Close(confd);
32 return 0;
33 }
时间： 2024-12-20 06:56:14