Question

使用参数＆＃34; server＆＃34;调用程序时然后＆＃34; runserver＆＃34;方法正在执行，事情正常。只是printf()语句没有打印任何内容。但是，当我打电话给＆＃34; runclient＆＃34;方法printf之前工作正常。为什么会这样？怎么解决这个问题？

#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <strings.h>
#include <sys/types.h>
#include <netdb.h>

void error(char *msg)
{
    perror(msg);
    exit(1);
}

int runclient()
{
    int sockfd, portno, n;

    struct sockaddr_in serv_addr;
    struct hostent *server;

    char buffer[256];

    portno = 1024;
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0)
        error("ERROR opening socket");
    server = gethostbyname("localhost");
    if (server == NULL) {
        fprintf(stderr,"ERROR, no such host\n");
        exit(0);
    }
    bzero((char *) &serv_addr, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    bcopy((char *)server->h_addr,
          (char *)&serv_addr.sin_addr.s_addr,
          server->h_length);
    serv_addr.sin_port = htons(portno);
    if (connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) < 0)
        error("ERROR connecting");
    printf("Please enter the message: ");
    bzero(buffer,256);
    fgets(buffer,255,stdin);
    n = write(sockfd,buffer,strlen(buffer));
    if (n < 0)
        error("ERROR writing to socket");
    bzero(buffer,256);
    n = read(sockfd,buffer,255);
    if (n < 0)
        error("ERROR reading from socket");
    printf("%s\n",buffer);
    return 0;
}

int runserver(){
    int sockfd, portno, clilen;
    char buffer[256];
    struct sockaddr_in serv_addr, cli_addr;
    int n;
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0)
        error("ERROR opening socket");
    //bzero((char *) &serv_addr, sizeof(serv_addr));
    portno = 1024;
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = INADDR_ANY;
    serv_addr.sin_port = htons(portno);
    if (bind(sockfd, (struct sockaddr *) &serv_addr,
             sizeof(serv_addr)) < 0)
        error("ERROR on binding");
    listen(sockfd,5);
    clilen = sizeof(cli_addr);
    sockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);
    if (sockfd < 0)
        error("ERROR on accept");
    //bzero(buffer,256);
    n = read(sockfd,buffer,255);
    if (n < 0) error("ERROR reading from socket");
    printf("Here is the message: %s\n",buffer);
    n = write(sockfd,"I got your message",18);
    if (n < 0) error("ERROR writing to socket");
    return 0;
}


int main(int argc, char **argv)
{
    if(strcmp(argv[1],"server") == 0){
        printf("Starting Server .... ");
        runserver();

    } else {
        printf("Starting Client .... ");
        runclient();
    }

    return 0;
}

Answer 1

写入终端时，

#!usr/bin/python import sys import json args=sys.stdin.readlines() #args comes in as a list with one item in it which is the parameter that you sent in from javascript arguments=args[0] print "Content-Type: text/html" print "" def getTasks(userName): """This function will do some processing and get the required return value""" taskList=[] #read JSON file and get the info. with open("Somefile.json", 'r') as data_file: usersDictionary = json.load(data_file) data_file.close() """...do some process ing of data here, which will set some data into the list called taskList""" return taskList #Return a list of all the tasks for the user. print json.dumps(getTasks(arguments)) """convert the json to a string and print it out. what you print out here will be what you will get as a string in the .responseText of the XMLHttpRequest object"""是行缓冲的，因此您必须在适当的位置拨打stdout或添加换行符。

在socket调用之前，printf无法正常工作

1 个答案: