devbox
不正经
这个屌丝很懒，什么也没留下！
关注作者
热门标签
热门文章
当前位置:   article > 正文

Unix网络编程代码 第5章 TCP客户/服务器程序示例_cpu_vendor_os header linux

作者：不正经 | 2024-02-28 12:19:04

赞

踩

cpu_vendor_os header linux

第3章 套接字编程简介

3.4 字节排序函数

  1.  
  2. #include <stdio.h>
  3. #include <stdlib.h>
  4. #define CPU_VENDOR_OS "i686-pc-linux-gnu"
  5. int main(int argc, char **argv)
  6. {
  7. 	union {
  8. 		short  s;
  9. 		char   c[sizeof(short)];
  10. 	} un;
  11.  
  12. 	un.s = 0x0102;
  13. 	printf("%s: ", CPU_VENDOR_OS);
  14. 	if (sizeof(short) == 2) {
  15. 		if (un.c[0] == 1 && un.c[1] == 2)
  16. 			printf("big-endian\n");
  17. 		else if (un.c[0] == 2 && un.c[1] == 1)
  18. 			printf("little-endian\n");
  19. 		else
  20. 			printf("unknown\n");
  21. 	} else
  22. 		printf("sizeof(short) = %d\n", sizeof(short));
  23.  
  24. 	exit(0);
  25. }

第5章 TCP客户/服务器程序示例

5.2 TCP回射服务器程序


  1. #include	<strings.h>
  2. #include	<sys/types.h>	/* basic system data types */
  3. #include	<sys/socket.h>	/* basic socket definitions */
  4. #include	<netinet/in.h>	/* sockaddr_in{} and other Internet defns */
  5. #include	<stdarg.h>	/* ANSI C header file */
  6. #include	<syslog.h>	/* for syslog() */
  7. #include	<errno.h>
  8. #include	<stdio.h>
  9. #include	<string.h>
  10. #include	<unistd.h>
  11. #include	<stdlib.h>
  12. int daemon_proc;		/* set nonzero by daemon_init() */
  13. #define	SA	struct sockaddr
  14. #define	MAXLINE		4096	/* max text line length */
  15. #define	SERV_PORT		 9877	/* TCP and UDP */
  16. #define	LISTENQ		1024	/* 2nd argument to listen() */
  17. void err_doit(int errnoflag, int level, const char *fmt, va_list ap)
  18. {
  19. 	int errno_save, n;
  20. 	char buf[MAXLINE + 1];
  21.  
  22. 	errno_save = errno;	/* value caller might want printed */
  23. #ifdef	HAVE_VSNPRINTF
  24. 	vsnprintf(buf, MAXLINE, fmt, ap);	/* safe */
  25. #else
  26. 	vsprintf(buf, fmt, ap);	/* not safe */
  27. #endif
  28. 	n = strlen(buf);
  29. 	if (errnoflag)
  30. 		snprintf(buf + n, MAXLINE - n, ": %s", strerror(errno_save));
  31. 	strcat(buf, "\n");
  32.  
  33. 	if (daemon_proc) {
  34. 		syslog(level, "%s",buf);
  35. 	} else {
  36. 		fflush(stdout);	/* in case stdout and stderr are the same */
  37. 		fputs(buf, stderr);
  38. 		fflush(stderr);
  39. 	}
  40. 	return;
  41. }
  42.  
  43. void err_sys(const char *fmt, ...)
  44. {
  45. 	va_list ap;
  46.  
  47. 	va_start(ap, fmt);
  48. 	err_doit(1, LOG_ERR, fmt, ap);
  49. 	va_end(ap);
  50. 	exit(1);
  51. }
  52.  
  53. int Socket(int family, int type, int protocol)
  54. {
  55. 	int n;
  56.  
  57. 	if ((n = socket(family, type, protocol)) < 0)
  58. 		err_sys("socket error");
  59. 	return (n);
  60. }
  61.  
  62. void Bind(int fd, const struct sockaddr *sa, socklen_t salen)
  63. {
  64. 	if (bind(fd, sa, salen) < 0)
  65. 		err_sys("bind error");
  66. }
  67.  
  68. void Listen(int fd, int backlog)
  69. {
  70. 	char *ptr;
  71.  
  72. 	/*4can override 2nd argument with environment variable */
  73. 	if ((ptr = getenv("LISTENQ")) != NULL)
  74. 		backlog = atoi(ptr);
  75.  
  76. 	if (listen(fd, backlog) < 0)
  77. 		err_sys("listen error");
  78. }
  79.  
  80. int Accept(int fd, struct sockaddr *sa, socklen_t * salenptr)
  81. {
  82. 	int n;
  83.  
  84.  again:
  85. 	if ((n = accept(fd, sa, salenptr)) < 0) {
  86. #ifdef	EPROTO
  87. 		if (errno == EPROTO || errno == ECONNABORTED)
  88. #else
  89. 		if (errno == ECONNABORTED)
  90. #endif
  91. 			goto again;
  92. 		else
  93. 			err_sys("accept error");
  94. 	}
  95. 	return (n);
  96. }
  97.  
  98. pid_t Fork(void)
  99. {
  100. 	pid_t pid;
  101.  
  102. 	if ((pid = fork()) == -1)
  103. 		err_sys("fork error");
  104. 	return (pid);
  105. }
  106.  
  107. void Close(int fd)
  108. {
  109. 	if (close(fd) == -1)
  110. 		err_sys("close error");
  111. }
  112.  
  113. ssize_t				/* Write "n" bytes to a descriptor. */
  114. writen(int fd, const void *vptr, size_t n)
  115. {
  116. 	size_t nleft;
  117. 	ssize_t nwritten;
  118. 	const char *ptr;
  119.  
  120. 	ptr = (const char *)vptr;
  121. 	nleft = n;
  122. 	while (nleft > 0) {
  123. 		if ((nwritten = write(fd, ptr, nleft)) <= 0) {
  124. 			if (nwritten < 0 && errno == EINTR)
  125. 				nwritten = 0;	/* and call write() again */
  126. 			else
  127. 				return (-1);	/* error */
  128. 		}
  129.  
  130. 		nleft -= nwritten;
  131. 		ptr += nwritten;
  132. 	}
  133. 	return (n);
  134. }
  135.  
  136. void Writen(int fd, void *ptr, int nbytes)
  137. {
  138. 	if (writen(fd, ptr, nbytes) != nbytes)
  139. 		err_sys("writen error");
  140. }
  141.  
  142. void str_echo(int sockfd)
  143. {
  144. 	ssize_t n;
  145. 	char buf[MAXLINE];
  146.  
  147.  again:
  148. 	while ((n = read(sockfd, buf, MAXLINE)) > 0)
  149. 		Writen(sockfd, buf, n);
  150.  
  151. 	if (n < 0 && errno == EINTR)
  152. 		goto again;
  153. 	else if (n < 0)
  154. 		err_sys("str_echo: read error");
  155. }
  156.  
  157. int main()
  158. {
  159. 	int listenfd, connfd;
  160. 	pid_t childpid;
  161. 	socklen_t clilen;
  162. 	struct sockaddr_in cliaddr, servaddr;
  163.  
  164. 	listenfd = Socket(AF_INET, SOCK_STREAM, 0);
  165.  
  166. 	bzero(&servaddr, sizeof(servaddr));
  167. 	servaddr.sin_family = AF_INET;
  168. 	servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
  169. 	servaddr.sin_port = htons(SERV_PORT);
  170.  
  171. 	Bind(listenfd, (SA *) & servaddr, sizeof(servaddr));
  172.  
  173. 	Listen(listenfd, LISTENQ);
  174.  
  175. 	for (;;) {
  176. 		clilen = sizeof(cliaddr);
  177. 		connfd = Accept(listenfd, (SA *) & cliaddr, &clilen);
  178.  
  179. 		if ((childpid = Fork()) == 0) {	/* child process */
  180. 			Close(listenfd);	/* close listening socket */
  181. 			str_echo(connfd);	/* process the request */
  182. 			exit(0);
  183. 		}
  184. 		Close(connfd);	/* parent closes connected socket */
  185. 	}
  186. }

5.4 TCP回射客户程序

  1. #include	<netinet/in.h>	/* sockaddr_in{} and other Internet defns */
  2. #include	<strings.h>
  3. #include	<stdarg.h>	/* ANSI C header file */
  4. #include	<syslog.h>	/* for syslog() */
  5. #include	<errno.h>
  6. #include	<string.h>
  7. #include	<stdio.h>
  8. #include	<stdlib.h>
  9. #include	<arpa/inet.h>
  10. #include	<unistd.h>
  11. #define	MAXLINE		4096	/* max text line length */
  12. #define	SERV_PORT		 9877	/* TCP and UDP */
  13. int daemon_proc;		/* set nonzero by daemon_init() */
  14. #define	SA	struct sockaddr
  15. void err_doit(int errnoflag, int level, const char *fmt, va_list ap)
  16. {
  17. 	int errno_save, n;
  18. 	char buf[MAXLINE + 1];
  19.  
  20. 	errno_save = errno;	/* value caller might want printed */
  21. #ifdef	HAVE_VSNPRINTF
  22. 	vsnprintf(buf, MAXLINE, fmt, ap);	/* safe */
  23. #else
  24. 	vsprintf(buf, fmt, ap);	/* not safe */
  25. #endif
  26. 	n = strlen(buf);
  27. 	if (errnoflag)
  28. 		snprintf(buf + n, MAXLINE - n, ": %s", strerror(errno_save));
  29. 	strcat(buf, "\n");
  30.  
  31. 	if (daemon_proc) {
  32. 		syslog(level, "%s",buf);
  33. 	} else {
  34. 		fflush(stdout);	/* in case stdout and stderr are the same */
  35. 		fputs(buf, stderr);
  36. 		fflush(stderr);
  37. 	}
  38. 	return;
  39. }
  40.  
  41. void err_quit(const char *fmt, ...)
  42. {
  43. 	va_list ap;
  44.  
  45. 	va_start(ap, fmt);
  46. 	err_doit(0, LOG_ERR, fmt, ap);
  47. 	va_end(ap);
  48. 	exit(1);
  49. }
  50.  
  51. void err_sys(const char *fmt, ...)
  52. {
  53. 	va_list ap;
  54.  
  55. 	va_start(ap, fmt);
  56. 	err_doit(1, LOG_ERR, fmt, ap);
  57. 	va_end(ap);
  58. 	exit(1);
  59. }
  60.  
  61. int Socket(int family, int type, int protocol)
  62. {
  63. 	int n;
  64.  
  65. 	if ((n = socket(family, type, protocol)) < 0)
  66. 		err_sys("socket error");
  67. 	return (n);
  68. }
  69.  
  70. void Inet_pton(int family, const char *strptr, void *addrptr)
  71. {
  72. 	int n;
  73.  
  74. 	if ((n = inet_pton(family, strptr, addrptr)) < 0)
  75. 		err_sys("inet_pton error for %s", strptr);	/* errno set */
  76. 	else if (n == 0)
  77. 		err_quit("inet_pton error for %s", strptr);	/* errno not set */
  78.  
  79. 	/* nothing to return */
  80. }
  81.  
  82. void Connect(int fd, const struct sockaddr *sa, socklen_t salen)
  83. {
  84. 	if (connect(fd, sa, salen) < 0)
  85. 		err_sys("connect error");
  86. }
  87.  
  88. ssize_t writen(int fd, const void *vptr, size_t n)
  89. {
  90. 	size_t nleft;
  91. 	ssize_t nwritten;
  92. 	const char *ptr;
  93.  
  94. 	ptr = (const char *)vptr;
  95. 	nleft = n;
  96. 	while (nleft > 0) {
  97. 		if ((nwritten = write(fd, ptr, nleft)) <= 0) {
  98. 			if (nwritten < 0 && errno == EINTR)
  99. 				nwritten = 0;	/* and call write() again */
  100. 			else
  101. 				return (-1);	/* error */
  102. 		}
  103.  
  104. 		nleft -= nwritten;
  105. 		ptr += nwritten;
  106. 	}
  107. 	return (n);
  108. }
  109.  
  110. void Writen(int fd, void *ptr, int nbytes)
  111. {
  112. 	if (writen(fd, ptr, nbytes) != nbytes)
  113. 		err_sys("writen error");
  114. }
  115.  
  116. char *Fgets(char *ptr, int n, FILE * stream)
  117. {
  118. 	char *rptr;
  119.  
  120. 	if ((rptr = fgets(ptr, n, stream)) == NULL && ferror(stream))
  121. 		err_sys("fgets error");
  122.  
  123. 	return (rptr);
  124. }
  125.  
  126. void Fputs(const char *ptr, FILE * stream)
  127. {
  128. 	if (fputs(ptr, stream) == EOF)
  129. 		err_sys("fputs error");
  130. }
  131.  
  132. static int read_cnt;
  133. static char *read_ptr;
  134. static char read_buf[MAXLINE];
  135. static ssize_t my_read(int fd, char *ptr)
  136. {
  137.  
  138. 	if (read_cnt <= 0) {
  139.  again:
  140. 		if ((read_cnt = read(fd, read_buf, sizeof(read_buf))) < 0) {
  141. 			if (errno == EINTR)
  142. 				goto again;
  143. 			return (-1);
  144. 		} else if (read_cnt == 0)
  145. 			return (0);
  146. 		read_ptr = read_buf;
  147. 	}
  148.  
  149. 	read_cnt--;
  150. 	*ptr = *read_ptr++;
  151. 	return (1);
  152. }
  153.  
  154. ssize_t readline(int fd, void *vptr, int maxlen)
  155. {
  156. 	ssize_t n, rc;
  157. 	char c, *ptr;
  158.  
  159. 	ptr = (char *)vptr;
  160. 	for (n = 1; n < maxlen; n++) {
  161. 		if ((rc = my_read(fd, &c)) == 1) {
  162. 			*ptr++ = c;
  163. 			if (c == '\n')
  164. 				break;	/* newline is stored, like fgets() */
  165. 		} else if (rc == 0) {
  166. 			*ptr = 0;
  167. 			return (n - 1);	/* EOF, n - 1 bytes were read */
  168. 		} else
  169. 			return (-1);	/* error, errno set by read() */
  170. 	}
  171.  
  172. 	*ptr = 0;		/* null terminate like fgets() */
  173. 	return (n);
  174. }
  175.  
  176. ssize_t Readline(int fd, void *ptr, size_t maxlen)
  177. {
  178. 	ssize_t n;
  179.  
  180. 	if ((n = readline(fd, ptr, maxlen)) < 0)
  181. 		err_sys("readline error");
  182. 	return (n);
  183. }
  184.  
  185. void str_cli(FILE * fp, int sockfd)
  186. {
  187. 	char sendline[MAXLINE], recvline[MAXLINE];
  188.  
  189. 	while (Fgets(sendline, MAXLINE, fp) != NULL) {
  190.  
  191. 		Writen(sockfd, sendline, strlen(sendline));
  192.  
  193. 		if (Readline(sockfd, recvline, MAXLINE) == 0)
  194. 			err_quit("str_cli: server terminated prematurely");
  195.  
  196. 		Fputs(recvline, stdout);
  197. 	}
  198. }
  199.  
  200. int main(int argc, char **argv)
  201. {
  202. 	int sockfd;
  203. 	struct sockaddr_in servaddr;
  204.  
  205. 	if (argc != 2)
  206. 		err_quit("usage: tcpcli <IPaddress>");
  207.  
  208. 	sockfd = Socket(AF_INET, SOCK_STREAM, 0);
  209.  
  210. 	bzero(&servaddr, sizeof(servaddr));
  211. 	servaddr.sin_family = AF_INET;
  212. 	servaddr.sin_port = htons(SERV_PORT);
  213. 	Inet_pton(AF_INET, argv[1], &servaddr.sin_addr);
  214.  
  215. 	Connect(sockfd, (SA *) & servaddr, sizeof(servaddr));
  216.  
  217. 	str_cli(stdin, sockfd);	/* do it all */
  218.  
  219. 	exit(0);
  220. }

5.10 wait和waitpid函数

  1. //带上信号处理函数的server
  2. #define _POSIX_SOURCE
  3. #include	<strings.h>
  4. #include	<signal.h>
  5. #include	<sys/types.h>	/* basic system data types */
  6. #include	<sys/socket.h>	/* basic socket definitions */
  7. #include	<netinet/in.h>	/* sockaddr_in{} and other Internet defns */
  8. #include	<stdarg.h>	/* ANSI C header file */
  9. #include	<syslog.h>	/* for syslog() */
  10. #include	<errno.h>
  11. #include	<stdio.h>
  12. #include	<string.h>
  13. #include	<unistd.h>
  14. #include	<stdlib.h>
  15. #include	<sys/wait.h>
  16. int daemon_proc;		/* set nonzero by daemon_init() */
  17. #define	SA	struct sockaddr
  18. #define	MAXLINE		4096	/* max text line length */
  19. #define	SERV_PORT		 9877	/* TCP and UDP */
  20. #define	LISTENQ		1024	/* 2nd argument to listen() */
  21. typedef void Sigfunc(int);	/* for signal handlers */
  22. void err_doit(int errnoflag, int level, const char *fmt, va_list ap)
  23. {
  24. 	int errno_save, n;
  25. 	char buf[MAXLINE + 1];
  26.  
  27. 	errno_save = errno;	/* value caller might want printed */
  28. #ifdef	HAVE_VSNPRINTF
  29. 	vsnprintf(buf, MAXLINE, fmt, ap);	/* safe */
  30. #else
  31. 	vsprintf(buf, fmt, ap);	/* not safe */
  32. #endif
  33. 	n = strlen(buf);
  34. 	if (errnoflag)
  35. 		snprintf(buf + n, MAXLINE - n, ": %s", strerror(errno_save));
  36. 	strcat(buf, "\n");
  37.  
  38. 	if (daemon_proc) {
  39. 		syslog(level, "%s", buf);
  40. 	} else {
  41. 		fflush(stdout);	/* in case stdout and stderr are the same */
  42. 		fputs(buf, stderr);
  43. 		fflush(stderr);
  44. 	}
  45. 	return;
  46. }
  47.  
  48. void err_sys(const char *fmt, ...)
  49. {
  50. 	va_list ap;
  51.  
  52. 	va_start(ap, fmt);
  53. 	err_doit(1, LOG_ERR, fmt, ap);
  54. 	va_end(ap);
  55. 	exit(1);
  56. }
  57.  
  58. int Socket(int family, int type, int protocol)
  59. {
  60. 	int n;
  61.  
  62. 	if ((n = socket(family, type, protocol)) < 0)
  63. 		err_sys("socket error");
  64. 	return (n);
  65. }
  66.  
  67. void Bind(int fd, const struct sockaddr *sa, socklen_t salen)
  68. {
  69. 	if (bind(fd, sa, salen) < 0)
  70. 		err_sys("bind error");
  71. }
  72.  
  73. void Listen(int fd, int backlog)
  74. {
  75. 	char *ptr;
  76.  
  77. 	/*4can override 2nd argument with environment variable */
  78. 	if ((ptr = getenv("LISTENQ")) != NULL)
  79. 		backlog = atoi(ptr);
  80.  
  81. 	if (listen(fd, backlog) < 0)
  82. 		err_sys("listen error");
  83. }
  84.  
  85. pid_t Fork(void)
  86. {
  87. 	pid_t pid;
  88.  
  89. 	if ((pid = fork()) == -1)
  90. 		err_sys("fork error");
  91. 	return (pid);
  92. }
  93.  
  94. void Close(int fd)
  95. {
  96. 	if (close(fd) == -1)
  97. 		err_sys("close error");
  98. }
  99.  
  100. ssize_t				/* Write "n" bytes to a descriptor. */
  101. writen(int fd, const void *vptr, size_t n)
  102. {
  103. 	size_t nleft;
  104. 	ssize_t nwritten;
  105. 	const char *ptr;
  106.  
  107. 	ptr = (const char *)vptr;
  108. 	nleft = n;
  109. 	while (nleft > 0) {
  110. 		if ((nwritten = write(fd, ptr, nleft)) <= 0) {
  111. 			if (nwritten < 0 && errno == EINTR)
  112. 				nwritten = 0;	/* and call write() again */
  113. 			else
  114. 				return (-1);	/* error */
  115. 		}
  116.  
  117. 		nleft -= nwritten;
  118. 		ptr += nwritten;
  119. 	}
  120. 	return (n);
  121. }
  122.  
  123. void Writen(int fd, void *ptr, int nbytes)
  124. {
  125. 	if (writen(fd, ptr, nbytes) != nbytes)
  126. 		err_sys("writen error");
  127. }
  128.  
  129. void str_echo(int sockfd)
  130. {
  131. 	ssize_t n;
  132. 	char buf[MAXLINE];
  133.  
  134.  again:
  135. 	while ((n = read(sockfd, buf, MAXLINE)) > 0)
  136. 		Writen(sockfd, buf, n);
  137.  
  138. 	if (n < 0 && errno == EINTR)
  139. 		goto again;
  140. 	else if (n < 0)
  141. 		err_sys("str_echo: read error");
  142. }
  143.  
  144. void sig_chld(int signo)
  145. {
  146. 	pid_t pid;
  147. 	int stat;
  148.  
  149. 	while ((pid = waitpid(-1, &stat, WNOHANG)) > 0)
  150. 		printf("child %d terminated\n", pid);
  151. 	return;
  152. }
  153.  
  154. Sigfunc *signal(int signo, Sigfunc * func)
  155. {
  156. 	struct sigaction act, oact;
  157.  
  158. 	act.sa_handler = func;
  159. 	sigemptyset(&act.sa_mask);
  160. 	act.sa_flags = 0;
  161. 	if (signo == SIGALRM) {
  162. #ifdef	SA_INTERRUPT
  163. 		act.sa_flags |= SA_INTERRUPT;	/* SunOS 4.x */
  164. #endif
  165. 	} else {
  166. #ifdef	SA_RESTART
  167. 		act.sa_flags |= SA_RESTART;	/* SVR4, 44BSD */
  168. #endif
  169. 	}
  170. 	if (sigaction(signo, &act, &oact) < 0)
  171. 		return (SIG_ERR);
  172. 	return (oact.sa_handler);
  173. }
  174.  
  175. Sigfunc *Signal(int signo, Sigfunc * func)
  176. {				/* for our signal() function */
  177. 	Sigfunc *sigfunc;
  178.  
  179. 	if ((sigfunc = signal(signo, func)) == SIG_ERR)
  180. 		err_sys("signal error");
  181. 	return (sigfunc);
  182. }
  183.  
  184. int main()
  185. {
  186. 	int listenfd, connfd;
  187. 	pid_t childpid;
  188. 	socklen_t clilen;
  189. 	struct sockaddr_in cliaddr, servaddr;
  190.  
  191. 	listenfd = Socket(AF_INET, SOCK_STREAM, 0);
  192.  
  193. 	bzero(&servaddr, sizeof(servaddr));
  194. 	servaddr.sin_family = AF_INET;
  195. 	servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
  196. 	servaddr.sin_port = htons(SERV_PORT);
  197.  
  198. 	Bind(listenfd, (SA *) & servaddr, sizeof(servaddr));
  199.  
  200. 	Listen(listenfd, LISTENQ);
  201.  
  202. 	Signal(SIGCHLD, sig_chld);	/* must call waitpid() */
  203.  
  204. 	for (;;) {
  205. 		clilen = sizeof(cliaddr);
  206. 		if ((connfd = accept(listenfd, (SA *) & cliaddr, &clilen)) < 0) {
  207. 			if (errno == EINTR)
  208. 				continue;	/* back to for() */
  209. 			else
  210. 				err_sys("accept error");
  211. 		}
  212.  
  213. 		if ((childpid = Fork()) == 0) {	/* child process */
  214. 			Close(listenfd);	/* close listening socket */
  215. 			str_echo(connfd);	/* process the request */
  216. 			exit(0);
  217. 		}
  218. 		Close(connfd);	/* parent closes connected socket */
  219. 	}
  220. }



                

        
声明：本文内容由网友自发贡献，不代表【wpsshop博客】立场，版权归原作者所有，本站不承担相应法律责任。如您发现有侵权的内容，请联系我们。转载请注明出处：https://www.wpsshop.cn/w/不正经/article/detail/158774
推荐阅读
相关标签
Copyright ©  2003-2013 www.wpsshop.cn  版权所有，并保留所有权利。

  
闽ICP备14008679号