程序编译时连接出错，请指教！

hantor

今天编译一个网络服务程序，在运行gcc -o server.o server.c 命令后，发现汇编没有问题，但连接出错。请高手指教。
下面把源代码和出错信息都给上。
#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <netdb.h>
#define TCP_PROTO  "tcp"
int proxy_port;  /* port to listen for proxy connections on */
struct sockaddr_in hostaddr;  /* host addr assembled from gethostbyname() */
extern int errno;  /* defined by libc.a */
extern char *sys_myerrlist[];
void parse_args (int argc, char **argv);
void daemonize (int servfd);
void do_proxy (int usersockfd);
void reap_status (void);
void errorout (char *msg);
/*This is my modification.
I'll tell you why we must do this later*/
typedef void Signal(int);
/****************************************************************
function: ...main
description: . Main level driver. After daemonizing the process, a socket is opened to listen for ........connections on the proxy port, connections are accepted and children are spawned to ........handle each new connection.
arguments: .. argc,argv you know what those are.
return value: .none.
calls: .... parse_args, do_proxy.
globals: ... reads proxy_port.
****************************************************************/
main (argc,argv)
int argc;
char **argv;
{
int clilen;
int childpid;
int sockfd, newsockfd;
struct sockaddr_in servaddr, cliaddr;
parse_args(argc,argv);
/* prepare an address struct to listen for connections */
bzero((char *) &servaddr, sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
servaddr.sin_port = proxy_port;
/* get a socket... */
if ((sockfd = socket(AF_INET,SOCK_STREAM,0)) < 0) {
/* get a socket... */
if ((sockfd = socket(AF_INET,SOCK_STREAM,0)) < 0) {
fputs("failed to create server socket\r\n",stderr);
exit(1);
}
/* ...and bind our address and port to it */
if(bind(sockfd,(struct sockaddr_in *) &servaddr,sizeof(servaddr)) < 0) {
fputs("faild to bind server socket to specified port\r\n",stderr);
exit(1);
}
/* get ready to accept with at most 5 clients waiting to connect */
listen(sockfd,5);
/* turn ourselves into a daemon */
daemonize(sockfd);
/* fall into a loop to accept new connections and spawn children */
while (1) {
/* accept the next connection */
clilen = sizeof(cliaddr);
newsockfd = accept(sockfd, (struct sockaddr_in *) &cliaddr, &clilen);
if (newsockfd < 0 && errno == EINTR)
continue;
/* a signal might interrupt our accept() call */
else if (newsockfd < 0)
/* something quite amiss -- kill the server */
errorout("failed to accept connection");
/* fork a child to handle this connection */
if ((childpid = fork()) == 0) {
close(sockfd);
do_proxy(newsockfd);
exit(0);
}
/* if fork() failed, the connection is silently dropped -- oops! */
lose(newsockfd);
}
}


出错信息如下：
[root@localhost server]#gcc   -o server.o server.c
gcc   -o server.o server.c
server.c: In function `main':
server.c:53: warning: passing arg 2 of `bind' from incompatible pointer type
server.c:65: warning: passing arg 2 of `accept' from incompatible pointer type
/tmp/ccdgt5qk.o(.text+0x1a): In function `main':
: undefined reference to `parse_args'
/tmp/ccdgt5qk.o(.text+0xdb): In function `main':
: undefined reference to `daemonize'
/tmp/ccdgt5qk.o(.text+0x123): In function `main':
: undefined reference to `errorout'
/tmp/ccdgt5qk.o(.text+0x14d): In function `main':
: undefined reference to `do_proxy'
/tmp/ccdgt5qk.o(.text+0x165): In function `main':
: undefined reference to `lose'
collect2: ld returned 1 exit status
make: *** [server.o] Error 1

MMMIX

把需要的库加上。BTW，既然你知道是链接错误，没有理由不清楚怎么排除。。。

hantor

这是一个简单网络服务器例程。
真的不知道该怎么排除错误，能不能告诉我是什么库。具体一点！！！
谢谢先！

MMMIX

不清楚，查下文档，或者搜索。

mymtom

楼主的代码不全啊！这里应该有需要的函数：
http://fanqiang.chinaunix.net/a4/b7/20010810/1200001101.html

hantor

原帖由 mymtom 于 2007-12-4 17:04 发表
楼主的代码不全啊！这里应该有需要的函数：
http://fanqiang.chinaunix.net/a4/b7/20010810/1200001101.html

用http://fanqiang.chinaunix.net/a4/b7/20010810/1200001101.html里的代码编译也出同样的错误！！
奇怪了。

hantor

原帖由 mymtom 于 2007-12-4 17:04 发表
楼主的代码不全啊！这里应该有需要的函数：
http://fanqiang.chinaunix.net/a4/b7/20010810/1200001101.html

mymtom，你提供的代码编译也出同样的错误。

用gcc -v server.o server.c时错误信息如下：

[root@localhost linux_3rd]#gcc -v server.o server.c
gcc: server.o: No such file or directory
Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/specs
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --                                              enable-shared --enable-threads=posix --disable-checking --with-system-zlib --enable-__cxa_atexit                                               --host=i386-redhat-linux
Thread model: posix
gcc version 3.2.2 20030222 (Red Hat Linux 3.2.2-5)
/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/cc1 -lang-c -v -D__GNUC__=3 -D__GNUC_MINOR__

swordfish.cn

回楼上的同志，你用 -v 来编译？

mymtom

经检查，原来的帖子
http://fanqiang.chinaunix.net/a4/b7/20010810/1200001101.html
的代码有点问题，拼写错误如close写成了lose， SIGCHLD写成了SIGHLD，还有就是有中文空格，再一个是作者关于sys_errlist改成sys_myerrlist的写法是错误的，其实sys_errlist很早就在C运行库里了。改了一下编译通过了，没有运行试验过。
附件里是编译过的代码

1. 
   
2. /*
   
3. * 转载:
   
4. * from [url]http://fanqiang.chinaunix.net/a4/b7/20010810/1200001101.html[/url]
   
5. * 为了回答 ChinaUnix.net hantor 的帖子改的程序，编译通过，没有运行试验
   
6. *
   
7.    Proxy源代码分析--谈谈如何学习linux网络编程
   
8.    本文出自:[url]http://www.china-pub.com[/url] 作者:李培源 (2001-08-10 12:00:00)
   
9. 
   
10. /*
    
11.    ◆main()函数
    
12.    -----------------------------------------------------------------
    
13. */
    
14. #include <stdio.h>
    
15. #include <ctype.h>
    
16. #include <errno.h>
    
17. #include <signal.h>
    
18. #include <sys/types.h>
    
19. #include <sys/socket.h>
    
20. #include <sys/file.h>
    
21. #include <sys/ioctl.h>
    
22. #include <sys/wait.h>
    
23. #include <sys/types.h>
    
24. #include <netdb.h>
    
25. 
    
26. #include <sys/select.h>
    
27. #include <netinet/in.h>
    
28. 
    
29. #define TCP_PROTO       "tcp"
    
30. 
    
31. typedef void Sigfunc(int);
    
32. int proxy_port;                 /* port to listen for proxy connections on */
    
33. struct sockaddr_in hostaddr;    /* host addr assembled from gethostbyname() */
    
34. extern int errno;               /* defined by libc.a */
    
35. extern char *sys_myerrlist[];
    
36. /* 原来的帖子搞错了，其实就应该是 sys_errlist */
    
37. #define sys_myerrlist sys_errlist
    
38. void parse_args (int argc, char **argv);
    
39. void daemonize (int servfd);
    
40. void do_proxy (int usersockfd);
    
41. void reap_status (void);
    
42. void errorout (char *msg);
    
43. /*This is my modification.
    
44. I'll tell you why we must do this later*/
    
45. typedef void Signal(int);
    
46. /****************************************************************
    
47. function: 　　　main
    
48. description:    Main level driver. After daemonizing the process,
    
49.                 a socket is opened to listen for connections on
    
50.                 the proxy port, connections are accepted and
    
51.                 children are spawned to handle each new connection.
    
52. arguments: 　　 argc,argv you know what those are.
    
53. return value: 　none.
    
54. calls: 　　　　 parse_args, do_proxy.
    
55. globals: 　　　 reads proxy_port.
    
56. ****************************************************************/
    
57. int main(int argc, char *argv[])
    
58. {
    
59.         int clilen;
    
60.         int childpid;
    
61.         int sockfd, newsockfd;
    
62.         struct sockaddr_in servaddr, cliaddr;
    
63.         parse_args(argc,argv);
    
64.         /* prepare an address struct to listen for connections */
    
65.         bzero((char *) &servaddr, sizeof(servaddr));
    
66.         servaddr.sin_family = AF_INET;
    
67.         servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    
68.         servaddr.sin_port = proxy_port;
    
69.         /* get a socket... */
    
70.         if ((sockfd = socket(AF_INET,SOCK_STREAM,0)) < 0) {
    
71.         fputs("failed to create server socket\r\n",stderr);
    
72.         exit(1);
    
73.         }
    
74.         /* ...and bind our address and port to it */
    
75.         if (bind(sockfd,(struct sockaddr *) &servaddr,sizeof(servaddr)) < 0)
    
76.         {
    
77.                 fputs("faild to bind server socket to specified port\r\n",stderr);
    
78.                 exit(1);
    
79.         }
    
80.         /* get ready to accept with at most 5 clients waiting to connect */
    
81.         listen(sockfd,5);
    
82.         /* turn ourselves into a daemon */
    
83.         daemonize(sockfd);
    
84.         /* fall into a loop to accept new connections and spawn children */
    
85.         while (1) {
    
86.                 /* accept the next connection */
    
87.                 clilen = sizeof(cliaddr);
    
88.                 newsockfd = accept(sockfd, (struct sockaddr *) &cliaddr, &clilen);
    
89.                 if (newsockfd < 0 && errno == EINTR)
    
90.                         continue;
    
91.                 /* a signal might interrupt our accept() call */
    
92.                 else if (newsockfd < 0)
    
93.                         /* something quite amiss -- kill the server */
    
94.                         errorout("failed to accept connection");
    
95.                 /* fork a child to handle this connection */
    
96.                 if ((childpid = fork()) == 0)
    
97.                 {
    
98.                         close(sockfd);
    
99.                         do_proxy(newsockfd);
    
100.                         exit(0);
     
101.                 }
     
102.                 /* if fork() failed, the connection is silently dropped -- oops! */
     
103.                 close(newsockfd);
     
104.         }
     
105. }
     
106. /* ----------------------------------------------------------------- */
     
107. /*
     
108.         ◆函数parse_args()
     
109. 
     
110.         此函数的定义是：void parse_args (int argc, char **argv);
     
111. */
     
112. /*-----------------------------------------------------------------*/
     
113. /****************************************************************
     
114. function:       parse_args
     
115. description:    parse the command line args.
     
116. arguments:      argc,argv you know what these are.
     
117. return value:   none.
     
118. calls:          none.
     
119. globals:        writes proxy_port, writes hostaddr.
     
120. ****************************************************************/
     
121. void parse_args (argc,argv)
     
122. int argc;
     
123. char **argv;
     
124. {
     
125.     int i;
     
126.     struct hostent *hostp;
     
127.     struct servent *servp;
     
128.     unsigned long inaddr;
     
129.     struct {
     
130.         char proxy_port [16];
     
131.         char isolated_host [64];
     
132.         char service_name [32];
     
133.     } pargs;
     
134.     if (argc < 4) {
     
135.           printf("usage: %s <proxy-port> <host> <service-name|port-number>\r\n", argv[0]);
     
136.           exit(1);
     
137.     }
     
138.     strcpy(pargs.proxy_port,argv[1]);
     
139.     strcpy(pargs.isolated_host,argv[2]);
     
140.     strcpy(pargs.service_name,argv[3]);
     
141.     for (i = 0; i < strlen(pargs.proxy_port); i++)
     
142.         if (!isdigit(*(pargs.proxy_port + i)))
     
143.             break;
     
144.     if (i == strlen(pargs.proxy_port))
     
145.         proxy_port = htons(atoi(pargs.proxy_port));
     
146.     else {
     
147.         printf("%s: invalid proxy port\r\n",pargs.proxy_port);
     
148.         exit(0);
     
149.     }
     
150.     bzero(&hostaddr,sizeof(hostaddr));
     
151.     hostaddr.sin_family = AF_INET;
     
152.     if ((inaddr = inet_addr(pargs.isolated_host)) != INADDR_NONE)
     
153.         bcopy(&inaddr,&hostaddr.sin_addr,sizeof(inaddr));
     
154.     else if ((hostp = gethostbyname(pargs.isolated_host)) != NULL)
     
155.         bcopy(hostp->h_addr,&hostaddr.sin_addr,hostp->h_length);
     
156.     else {
     
157.         printf("%s: unknown host\r\n",pargs.isolated_host);
     
158.         exit(1);
     
159.     }
     
160.     if ((servp = getservbyname(pargs.service_name,TCP_PROTO)) != NULL)
     
161.         hostaddr.sin_port = servp->s_port;
     
162.     else if (atoi(pargs.service_name) > 0)
     
163.         hostaddr.sin_port = htons(atoi(pargs.service_name));
     
164.     else {
     
165.         printf("%s: invalid/unknown service name or port number\r\n", pargs.service_name);
     
166.         exit(1);
     
167.     }
     
168. }
     
169. 
     
170. /*-----------------------------------------------------------------*/
     
171. 
     
172. /****************************************************************
     
173. function:     daemonize
     
174. description:  detach the server process from the current context,
     
175.               creating a pristine, predictable environment in
     
176.               which it will execute.
     
177. arguments:    servfd file descriptor in use by server.
     
178. return value: none.
     
179. calls:        none.
     
180. globals:      none.
     
181. ****************************************************************/
     
182. void daemonize (servfd)
     
183. int servfd;
     
184. {
     
185.     int childpid, fd, fdtablesize;
     
186.     /* ignore terminal I/O, stop signals */
     
187.       signal(SIGTTOU,SIG_IGN);
     
188.       signal(SIGTTIN,SIG_IGN);
     
189.       signal(SIGTSTP,SIG_IGN);
     
190.     /* fork to put us in the background (whether or not the user
     
191.      specified '&' on the command line */
     
192.     if ((childpid = fork()) < 0) {
     
193.         fputs("failed to fork first child\r\n",stderr);
     
194.         exit(1);
     
195.       }
     
196.     else if (childpid > 0)
     
197.       exit(0); /* terminate parent, continue in child */
     
198.       /* dissociate from process group */
     
199.     if (setpgrp(0,getpid())<0) {
     
200.         fputs("failed to become process group leader\r\n",stderr);
     
201.         exit(1);
     
202.     }
     
203.     /* lose controlling terminal */
     
204.     if ((fd = open("/dev/tty",O_RDWR)) >= 0) {
     
205.         ioctl(fd,TIOCNOTTY,NULL);
     
206.         close(fd);
     
207.     }
     
208.     /* close any open file descriptors */
     
209.     for (fd = 0, fdtablesize = getdtablesize(); fd < fdtablesize; fd++)
     
210.     if (fd != servfd)
     
211.       close(fd);
     
212.       /* set working directory to allow filesystems to be unmounted */
     
213.       chdir("/");
     
214.       /* clear the inherited umask */
     
215.       umask(0);
     
216.       /* setup zombie prevention */
     
217.       signal(SIGCHLD,(Sigfunc *)reap_status);
     
218.     }
     
219. 
     
220. /****************************************************************
     
221. function:       reap_status
     
222. description:    handle a SIGCLD signal by reaping the exit status
     
223.                 of the perished child, and discarding it.
     
224. arguments:      none.
     
225. return value:   none.
     
226. calls:          none.
     
227. globals:        none.
     
228. ****************************************************************/
     
229. void reap_status()
     
230. {
     
231.         int pid;
     
232.         /* union wait status; */
     
233.         int status;
     
234.         while ((pid = wait3(&status,WNOHANG,NULL)) > 0)
     
235.         ; /* loop while there are more dead children */
     
236. }
     
237. 
     
238. /****************************************************************
     
239. function:      do_proxy
     
240. description:   does the actual work of virtually connecting a
     
241.                client to the telnet service on the  isolated host.
     
242. arguments:     usersockfd socket to which the client is connected.
     
243. return value:  none.
     
244. calls:         none.
     
245. globals:       reads hostaddr.
     
246. ****************************************************************/
     
247. void do_proxy (usersockfd)
     
248. int usersockfd;
     
249. {
     
250.     int isosockfd;
     
251.     fd_set rdfdset;
     
252.     int connstat;
     
253.     int iolen;
     
254.     char buf[2048];
     
255.     /* open a socket to connect to the isolated host */
     
256.     if ((isosockfd = socket(AF_INET,SOCK_STREAM,0)) < 0)
     
257.     errorout("failed to create socket to host");
     
258.     /* attempt a connection */
     
259.     connstat = connect(isosockfd,(struct sockaddr *) &hostaddr, sizeof(hostaddr));
     
260.     switch (connstat) {
     
261.     case 0:
     
262.     break;
     
263.     case ETIMEDOUT:
     
264.     case ECONNREFUSED:
     
265.     case ENETUNREACH:
     
266.     strcpy(buf,sys_myerrlist[errno]);
     
267.     strcat(buf,"\r\n");
     
268.     write(usersockfd,buf,strlen(buf));
     
269.     close(usersockfd);
     
270.     exit(1);
     
271.     /* die peacefully if we can't establish a connection */
     
272.     break;
     
273.     default:
     
274.     errorout("failed to connect to host");
     
275.     }
     
276.     /* now we're connected, serve fall into the data echo loop */
     
277.     while (1) {
     
278.         /* Select for readability on either of our two sockets */
     
279.         FD_ZERO(&rdfdset);
     
280.         FD_SET(usersockfd,&rdfdset);
     
281.         FD_SET(isosockfd,&rdfdset);
     
282.     if (select(FD_SETSIZE,&rdfdset,NULL,NULL,NULL) < 0)
     
283.       errorout("select failed");
     
284.       /* is the client sending data? */
     
285.     if (FD_ISSET(usersockfd,&rdfdset)) {
     
286.         if ((iolen = read(usersockfd,buf,sizeof(buf))) <= 0)
     
287.           break; /* zero length means the client disconnected */
     
288.           write(isosockfd,buf,iolen);
     
289.           /* copy to host -- blocking semantics */
     
290.       }
     
291.     /* is the host sending data? */
     
292.     if (FD_ISSET(isosockfd,&rdfdset)) {
     
293.         if ((iolen = read(isosockfd,buf,sizeof(buf))) <= 0)
     
294.             break; /* zero length means the host disconnected */
     
295.             write(usersockfd,buf,iolen);
     
296.             /* copy to client -- blocking semantics */
     
297.         }
     
298.       }
     
299.       /* we're done with the sockets */
     
300.       close(isosockfd);
     
301.       close(usersockfd);
     
302.     }
     
303. 
     
304. /****************************************************************
     
305. function:    errorout
     
306. description: displays an error message on the console and kills
     
307.              the current process.
     
308. arguments:   msg -- message to be displayed.
     
309. return value: none -- does not return.
     
310. calls:       none.
     
311. globals:     none.
     
312. ****************************************************************/
     
313. void errorout (msg)
     
314. char *msg;
     
315. {
     
316.     FILE *console;
     
317.     console = fopen("/dev/console","a");
     
318.     fprintf(console,"proxyd: %s\r\n",msg);
     
319.     fclose(console);
     
320.     exit(1);
     
321. }
     
322. 
     

复制代码

hantor

原帖由 swordfish.cn 于 2007-12-4 22:52 发表
回楼上的同志，你用 -v 来编译？

回swordfish.cn，使用-v选项只是为了能看到gcc编译的时候查找了哪些库，因为这个程序是在链接的时候找不到相应的库。