如何在 C 中将 Enter 键作为输入读取？我想要一些这样的程序：
"Please enter a key to go to next line"
如何在 C 中添加这种类型的选项？
我是编程新手。
【问题讨论】：
getchar()。
您可以使用stdio.h 中的getc 函数等待某个键被按下。此 C 代码将等待按下回车键然后输出“继续！”：
#include <stdio.h>
int main(){
printf("Press any key to continue");
getc(stdin);
printf("Continued!");
return 0;
}
【讨论】：
如果我理解你的问题，你可以写：
printf("Press ENTER key to Continue\n");
getchar();
或者
printf("Press Any Key to Continue\n");
getch();
【讨论】：
只有另一个答案正确地触及了这一点。不要假设您的用户会服从您，即使他或她打算这样做。
// Ask user to do something
printf( "Press Enter to continue: " );
fflush( stdout );
// Wait for user to do it
int c;
do c = getchar();
while ((c != EOF) and (c != '\n'));
这会丢弃其他输入，直到按下 Enter 键或到达 EOF，使您的输入流处于已知状态。
如果您希望有无缓冲的输入，那就是完全不同的蠕虫。
【讨论】：
一堆getc() C 中的演示：
read_in_any_key.c：
#include <stdio.h>
int main()
{
printf("Press any key followed by Enter, or just Enter alone, to continue: ");
int c = getc(stdin);
printf("The first character you entered is decimal %i (\"%c\").\n", c, c);
return 0;
}
示例运行和输出。请注意，在最后一个示例中，我单独按了 Enter，因此它会将其打印为换行符。每个键的十进制数字可以在 ASCII 表中找到，例如：https://en.wikipedia.org/wiki/ASCII#Control_code_chart。
eRCaGuy_hello_world/c$ gcc -Wall -Wextra -Werror -O3 -std=c17 read_in_enter_key.c -o bin/a && bin/a Press any key followed by Enter, or just Enter alone, to continue: abc The first character you entered is decimal 97 ("a").
eRCaGuy_hello_world/c$ gcc -Wall -Wextra -Werror -O3 -std=c17 read_in_enter_key.c -o bin/a && bin/a Press any key followed by Enter, or just Enter alone, to continue: def The first character you entered is decimal 100 ("d").
eRCaGuy_hello_world/c$ gcc -Wall -Wextra -Werror -O3 -std=c17 read_in_enter_key.c -o bin/a && bin/a Press any key followed by Enter, or just Enter alone, to continue: FTL The first character you entered is decimal 70 ("F").
eRCaGuy_hello_world/c$ gcc -Wall -Wextra -Werror -O3 -std=c17 read_in_enter_key.c -o bin/a && bin/a Press any key followed by Enter, or just Enter alone, to continue: The first character you entered is decimal 10 (" ").
read_in_any_key.c：
#include <stdint.h> // For `uint8_t`, `int8_t`, etc.
#include <stdio.h> // For `printf()`
// int main(int argc, char *argv[]) // alternative prototype
int main()
{
printf("Press any key followed by Enter, or just Enter alone, to continue: ");
int c = getc(stdin);
printf("The first character you entered is decimal %i (\"%c\").\n", c, c);
// If you entered one or more characters above before pressing Enter, they
// are still in the stdin input stream's buffer, so let's read those out
// too, up to the newline char (`'\n'`) created by pressing Enter.
uint32_t charNum = 2;
while (c != '\n')
{
c = getc(stdin);
if (c == EOF)
{
printf("Failed to get char!\n");
break;
}
printf("char %-2u = decimal %i (\"%c\").\n", charNum, c, c);
charNum++;
}
return 0;
}
示例运行和输出。我输入abcdefghijklmnop，然后按Enter：
eRCaGuy_hello_world/c$ gcc -Wall -Wextra -Werror -O3 -std=c17 read_in_any_key.c -o bin/a && bin/a
Press any key followed by Enter, or just Enter alone, to continue: abcdefghijklmnop
The first character you entered is decimal 97 ("a").
char 2 = decimal 98 ("b").
char 3 = decimal 99 ("c").
char 4 = decimal 100 ("d").
char 5 = decimal 101 ("e").
char 6 = decimal 102 ("f").
char 7 = decimal 103 ("g").
char 8 = decimal 104 ("h").
char 9 = decimal 105 ("i").
char 10 = decimal 106 ("j").
char 11 = decimal 107 ("k").
char 12 = decimal 108 ("l").
char 13 = decimal 109 ("m").
char 14 = decimal 110 ("n").
char 15 = decimal 111 ("o").
char 16 = decimal 112 ("p").
char 17 = decimal 10 ("
").
read_until_only_enter_key.c：
#include <stdbool.h> // For `true` (`1`) and `false` (`0`) macros in C
#include <stdio.h> // For `printf()`
// Clear the stdin input stream by reading and discarding all incoming chars up to and including
// the Enter key's newline ('\n') char. Once we hit the newline char, stop calling `getc()`, as
// calls to `getc()` beyond that will block again, waiting for more user input.
void clearStdin()
{
// keep reading 1 more char as long as the end of the stream, indicated by the newline char,
// has NOT been reached
while (true)
{
int c = getc(stdin);
if (c == EOF || c == '\n')
{
break;
}
}
}
// Returns true if only Enter was pressed, and false otherwise
bool getOnlyEnterKeypress()
{
bool onlyEnterPressed = false;
printf("Press ONLY the Enter key to continue: ");
int firstChar = getc(stdin);
if (firstChar == '\n')
{
printf("Good! You pressed ONLY the Enter key!\n");
onlyEnterPressed = true;
}
else
{
printf("You failed. You pressed another key first.\n");
clearStdin();
}
return onlyEnterPressed;
}
// int main(int argc, char *argv[]) // alternative prototype
int main()
{
while (!getOnlyEnterKeypress()) {};
return 0;
}
示例运行和输出。请注意，当我只按下 Enter 时，程序直到最后才退出，之前没有更多的键。
eRCaGuy_hello_world/c$ gcc -Wall -Wextra -Werror -O3 -std=c17 read_until_only_enter_key.c -o bin/a && bin/a
Press ONLY the Enter key to continue: a
You failed. You pressed another key first.
Press ONLY the Enter key to continue: abc
You failed. You pressed another key first.
Press ONLY the Enter key to continue: w
You failed. You pressed another key first.
Press ONLY the Enter key to continue:
Good! You pressed ONLY the Enter key!
如果您想立即阅读按键，而不是等待按下 Enter 键，请参阅下方“进一步了解”部分顶部的链接。
【讨论】：