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我正在尝试使用以下程序从文件描述符'0'(STDIN)中读取用户输入。之前,它没有问题,但是在程序的其他部分发生了一些变化之后,它在读取输入时给我一个分段错误。我还删除了“FD_CLR(0,& readfds)”以查看它是否有效,但它不。你能检查问题出在哪里吗?从STDIN读取用户输入时出现分段错误
char *userInput;
FD_ZERO(&masterfds);
FD_SET(0, &masterfds);
FD_SET(udp_con, &masterfds);
maxfds = udp_con;
while(exit == false)
{
readfds = masterfds;
selectFunc = select(maxfds+1, &readfds, NULL, NULL, &tv);
if(selectFunc < 0)
{
message("error in select");
exit = true;
}
else if(selectFunc == 0) //If there is a timeout
{
}
else //If a file descriptor is activated
{
if(FD_ISSET(udp_con, &readfds)) //If there is an activity on udp_con
{
/*read the udp_con via recvfrom function */
}
if(FD_ISSET(0, &readfds)) //If There is an input from keyboard
{
/* When it reaches to this part, the program shows a "segmentation fault" error */
fgets(userInput, sizeof(userInput), stdin);
int len = strlen(userInput) - 1;
if (userInput[len] == '\n')
{
userInput[len] = '\0';
}
string str = userInput;
cout<<"The user said: "<<str<<endl;
commandDetector(str);
FD_CLR(0, &readfds);
}
}
}
如何为'userInput'声明,并且任何与完成它在达到这段代码之前? –
@MarkkuK。对不起,我忘记了添加userInput声明语句。我刚刚编辑了我的第一篇文章,并在代码的开头添加了它。 – Amir