linux socket基礎

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一個簡單的用戶端擷取伺服器時間的例子：

伺服器代碼：

#include <iostream>#include "unp.h"#include "my_err.h"#define DEFAULT_PORT 8000int main(int argc, const char * argv[]){    int listenfd, connfd;    struct sockaddr_in servaddr;    char buff[MAXLINE];    time_t ticks;    listenfd = Socket(AF_INET, SOCK_STREAM, 0);        bzero(&servaddr, sizeof(servaddr));    servaddr.sin_family = AF_INET;    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);    servaddr.sin_port = htons(DEFAULT_PORT); //連接埠號碼        Bind(listenfd, (SA *) &servaddr, sizeof(servaddr));        Listen(listenfd, LISTENQ);        for ( ; ; ){        std::cout << "wait connect" << std::endl;        connfd = Accept(listenfd, (SA *) NULL, NULL);        ticks = time(NULL);        snprintf(buff, sizeof(buff), "%.24s\r\n", ctime(&ticks));        Write(connfd, buff, strlen(buff));                Close(connfd);    }    std::cout << "Hello, World!\n";    return 0;}

用戶端代碼：

#include <iostream>#include "unp.h"#include "my_err.h"int main(int argc, const char * argv[]){    int sockfd, n;    char recvline[MAXLINE + 1];    struct sockaddr_in servaddr;//    if (argc != 2)//        err_quit("usage: a.out <Ipaddress>");        if ( (sockfd = Socket(AF_INET, SOCK_STREAM, 0)) <0)        err_sys("socket error");     bzero(&servaddr, sizeof(servaddr));    servaddr.sin_family = AF_INET;    servaddr.sin_port = htons(8000);    if (inet_pton(AF_INET, "192.168.1.59", &servaddr.sin_addr) <= 0) //127.0.0.1        err_quit("inet_pton error for %s", argv[1]);    if (connect(sockfd, (SA *) &servaddr, sizeof(servaddr)) < 0 )        err_sys("connect error");    while ( (n = read(sockfd, recvline, MAXLINE)) > 0 ) {        recvline[n] = 0;        if (fputs(recvline , stdout) == EOF)            err_sys("fputs error");    }    if (n < 0 )        err_sys("read error");    return 0;}

my_err.h 檔案

#ifndef time1_my_err_h#define time1_my_err_h#include <errno.h> /* for definition of errno */#include <stdarg.h> /* ISO C variable aruments */static void err_doit(int, int, const char *, va_list);/* * Nonfatal error related to a system call. * Print a message and return. */voiderr_ret(const char *fmt, ...){    va_list ap;        va_start(ap, fmt);    err_doit(1, errno, fmt, ap);    va_end(ap);}/* * Fatal error related to a system call. * Print a message and terminate. */voiderr_sys(const char *fmt, ...){    va_list ap;        va_start(ap, fmt);    err_doit(1, errno, fmt, ap);    va_end(ap);    exit(1);}/* * Fatal error unrelated to a system call. * Error code passed as explict parameter. * Print a message and terminate. */voiderr_exit(int error, const char *fmt, ...){    va_list ap;        va_start(ap, fmt);    err_doit(1, error, fmt, ap);    va_end(ap);    exit(1);}/* * Fatal error related to a system call. * Print a message, dump core, and terminate. */voiderr_dump(const char *fmt, ...){    va_list ap;        va_start(ap, fmt);    err_doit(1, errno, fmt, ap);    va_end(ap);    abort(); /* dump core and terminate */    exit(1); /* shouldn't get here */}/* * Nonfatal error unrelated to a system call. * Print a message and return. */voiderr_msg(const char *fmt, ...){    va_list ap;        va_start(ap, fmt);    err_doit(0, 0, fmt, ap);    va_end(ap);}/* * Fatal error unrelated to a system call. * Print a message and terminate. */voiderr_quit(const char *fmt, ...){    va_list ap;        va_start(ap, fmt);    err_doit(0, 0, fmt, ap);    va_end(ap);    exit(1);}/* * Print a message and return to caller. * Caller specifies "errnoflag". */static voiderr_doit(int errnoflag, int error, const char *fmt, va_list ap){    char buf[MAXLINE];    vsnprintf(buf, MAXLINE, fmt, ap);    if (errnoflag)        snprintf(buf+strlen(buf), MAXLINE-strlen(buf), ": %s",                 strerror(error));    strcat(buf, "\n");    fflush(stdout); /* in case stdout and stderr are the same */    fputs(buf, stderr);    fflush(NULL); /* flushes all stdio output streams */}intSocket(int family, int type, int protocol){intn;    if ( (n = socket(family, type, protocol)) < 0)err_sys("socket error");return(n);}voidBind(int fd, const struct sockaddr *sa, socklen_t salen){if (bind(fd, sa, salen) < 0)err_sys("bind error");}voidClose(int fd){if (close(fd) == -1)err_sys("close error");}voidWrite(int fd, void *ptr, size_t nbytes){if (write(fd, ptr, nbytes) != nbytes)err_sys("write error");}intAccept(int fd, struct sockaddr *sa, socklen_t *salenptr){intn;    again:if ( (n = accept(fd, sa, salenptr)) < 0) {#ifdefEPROTOif (errno == EPROTO || errno == ECONNABORTED)#else            if (errno == ECONNABORTED)#endif                goto again;            else                err_sys("accept error");}return(n);}voidListen(int fd, int backlog){char*ptr;        /*4can override 2nd argument with environment variable */if ( (ptr = getenv("LISTENQ")) != NULL)backlog = atoi(ptr);    if (listen(fd, backlog) < 0)err_sys("listen error");}#endif

對比 window socket    http://blog.csdn.net/tutuboke/article/details/45799667

linux socket基礎