C语言 C 在按键时退出无限循环
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C exit from infinite loop on keypress
提问by Ragnis
How can I exit from an infinite loop, when a key is pressed? Currently I'm using getch, but it will start blocking my loop as soon, as there is no more input to read.
按下某个键时，如何退出无限循环？目前我正在使用 getch，但它会尽快开始阻塞我的循环，因为没有更多的输入可供读取。
采纳答案by Talha Ahmed Khan
I would suggest that you go throgh this article.
我建议你去看这篇文章。
回答by Rudy Velthuis
If you are using getch()from conio.hanyway, try to use kbhit()instead. Note that both getch()and kbhit()- conio.h, in fact - are not standard C.
如果您正在使用getch()from conio.h，请尝试使用kbhit()。请注意，getch()和kbhit()-conio.h事实上 - 都不是标准的 C。
回答by taskinoor
The function kbhit()from conio.hreturns non-zero value if any key is pressed but it does not block like getch(). Now, this is obviously not standard. But as you are already using getch()from conio.h, I think your compiler has this.
如果按下任何键，则函数kbhit()fromconio.h返回非零值，但它不会像getch(). 现在，这显然不是标准的。但是由于您已经在使用getch()from conio.h，我认为您的编译器具有此功能。
if (kbhit()) {
// keyboard pressed
}
From Wikipedia,
来自维基百科，
conio.h is a C header file used in old MS-DOS compilers to create text user interfaces. It is not described in The C Programming Language book, and it is not part of the C standard library, ISO C nor is it required by POSIX.
Most C compilers that target DOS, Windows 3.x, Phar Lap, DOSX, OS/2, or Win321have this header and supply the associated library functions in the default C library. Most C compilers that target UNIX and Linux do not have this header and do not supply the library functions.
conio.h 是旧 MS-DOS 编译器中用于创建文本用户界面的 C 头文件。The C Programming Language 一书中没有描述它，它不是 C 标准库、ISO C 的一部分，也不是 POSIX 所要求的。
大多数面向 DOS、Windows 3.x、Phar Lap、DOSX、OS/2 或 Win32 1 的C 编译器都有这个头文件并在默认 C 库中提供相关的库函数。大多数面向 UNIX 和 Linux 的 C 编译器没有这个头文件，也不提供库函数。
回答by Milind Deore
If you do not want to use non-standard, non-blocking way and yet graceful exit. Use signals and Ctrl+Cwith user provided signal handler to clean up. Something like this:
如果你不想使用非标准的、非阻塞的方式而优雅地退出。使用信号和Ctrl+C以及用户提供的信号处理程序进行清理。像这样的东西：
#include <stdio.h>
#include <signal.h>
#include <stdlib.h>
/* Signal Handler for SIGINT */
void sigint_handler(int sig_num)
{
/* Reset handler to catch SIGINT next time.
Refer http://en.cppreference.com/w/c/program/signal */
printf("\n User provided signal handler for Ctrl+C \n");
/* Do a graceful cleanup of the program like: free memory/resources/etc and exit */
exit(0);
}
int main ()
{
signal(SIGINT, sigint_handler);
/* Infinite loop */
while(1)
{
printf("Inside program logic loop\n");
}
return 0;
}
回答by user6060781
// Include stdlib.h to execute exit function
int char ch;
int i;
clrscr();
void main(){
printf("Print 1 to 5 again and again");
while(1){
for(i=1;i<=5;i++)
printf("\n%d",i);
ch=getch();
if(ch=='Q')// Q for Quit
exit(0);
}//while loop ends here
getch();
}
