UNP学习笔记（第三十章 客户/服务器程序设计范式）

TCP测试用客户程序

 1 #include    "unp.h"
 2 
 3 #define    MAXN    16384        /* max # bytes to request from server */
 4 
 5 int
 6 main(int argc, char **argv)
 7 {
 8     int        i, j, fd, nchildren, nloops, nbytes;
 9     pid_t    pid;
10     ssize_t    n;
11     char    request[MAXLINE], reply[MAXN];
12 
13     if (argc != 6)
14         err_quit("usage: client <hostname or IPaddr> <port> <#children> "
15                  "<#loops/child> <#bytes/request>");
16 
17     nchildren = atoi(argv[3]);
18     nloops = atoi(argv[4]);
19     nbytes = atoi(argv[5]);
20     snprintf(request, sizeof(request), "%d\n", nbytes); /* newline at end */
21 
22     for (i = 0; i < nchildren; i++) {
23         if ( (pid = Fork()) == 0) {        /* child */
24             for (j = 0; j < nloops; j++) {
25                 fd = Tcp_connect(argv[1], argv[2]);
26 
27                 Write(fd, request, strlen(request));
28 
29                 if ( (n = Readn(fd, reply, nbytes)) != nbytes)
30                     err_quit("server returned %d bytes", n);
31 
32                 Close(fd);        /* TIME_WAIT on client, not server */
33             }
34             printf("child %d done\n", i);
35             exit(0);
36         }
37         /* parent loops around to fork() again */
38     }
39 
40     while (wait(NULL) > 0)    /* now parent waits for all children */
41         ;
42     if (errno != ECHILD)
43         err_sys("wait error");
44 
45     exit(0);
46 }

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