等待在C用户输入？ [英] Wait for user input in C?

问题描述

我试图做一个简单的命令暂停用户输入。我认为它会在的bash脚本是有用的。

I'm trying to make a simple command that pauses for user input. I think it'll be useful in Bash scripts.

下面是我的code：

#include <stdio.h>
int main() {
  char key[1];
  puts("Press any key to continue...");
  fgets(key,1,stdin);
}

它甚至没有暂停用户输入。

It doesn't even pause for user input.

我之前试过用残培（）（ncurses的）。事情的经过后，屏幕一片空白，当我pressed一个键，就回什么最初是在屏幕上，我看到：

I tried earlier to use getch() (ncurses). What happened is, the screen went blank and when I pressed a key, it went back to what was originally on the screen, and I saw:

$ ./pause
Press any key to continue...
$

这有点是我想要的。但是，所有我想要的是暂停相当于在DOS / Windows命令（我使用Linux）。

It's somewhat what I wanted. But all I want is the equivalent of the pause command in DOS/Windows (I use Linux).

推荐答案

从GNU C库手册：

功能：字符*与fgets（字符* S，诠释计数，FILE *流）

Function: char * fgets (char *s, int count, FILE *stream)

在与fgets
  函数读取从流字符流直至并包括一个
  换行符并将它们存储在字符串s，加入空
  字符来标记串的结束。您必须提供数
  价值在航天，，但字符的字符数读的是
  顶多算 - 1 即可。额外的字符空间用于容纳空
  字符在字符串的末尾。

The fgets function reads characters from the stream stream up to and including a newline character and stores them in the string s, adding a null character to mark the end of the string. You must supply count characters worth of space in s, but the number of characters read is at most count − 1. The extra character space is used to hold the null character at the end of the string.

因此​​，与fgets（键1，标准输入）; 0读取字符和回报。 （阅读：立即）

So, fgets(key,1,stdin); reads 0 characters and returns. (read: immediately)

使用的getchar 或函数getline 代替。

编辑：与fgets也不会返回一旦计数字符都可以在流，它一直等待一个换行符，然后读取计数字符，因此任意键可能不会在这种情况下，那么正确的写法。

fgets also doesn't return once count characters are available on the stream, it keeps waiting for a newline and then reads count characters, so "any key" might not be the correct wording in this case then.

您可以使用此<一个href=\"http://faq.cprogramming.com/cgi-bin/smartfaq.cgi?answer=1042856625&id=1043284385\">example为避免线路缓冲：

You can use this example to avoid line-buffering:

#include <stdio.h>
#include <termios.h>
#include <unistd.h>

int mygetch ( void ) 
{
  int ch;
  struct termios oldt, newt;

  tcgetattr ( STDIN_FILENO, &oldt );
  newt = oldt;
  newt.c_lflag &= ~( ICANON | ECHO );
  tcsetattr ( STDIN_FILENO, TCSANOW, &newt );
  ch = getchar();
  tcsetattr ( STDIN_FILENO, TCSANOW, &oldt );

  return ch;
}

int main()
{
    printf("Press any key to continue.\n");
    mygetch();
    printf("Bye.\n");
}

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