问题描述
我偶然在Windows中用Turbo C ++ IDE编写了2016年的代码那是接受密码
I stumbled upon a code from 2016 written in the Turbo C++ IDE in windowsIt was to accept passwords
char pass;
for (length = 0;;)
{
pass=getch();
if (pass == 13)
{
break;
}
if ((pass >= 'A' && pass <= 'Z') || (pass >= 'a' && pass <= 'z') || (pass >= '0' && pass <= '9') || (pass == '!' || '@' || '#' || '$' || '%' || '^' || '&' || '*' || '(' || ')'))
{
str[length] = pass;
++length;
cout << "#";
}
}
如果没有 linux 的getch方法来显示类似********的输出,是否可以替代此方法?我尝试了scanf,但没有成功,因为它首先获取了整个输入,后来又给出了输出
is there any replacement for this without the getch method for linux to show output like this ******** ? I tried scanf but that didnt work cause it took the whole input first and gave the output later
推荐答案
C ++中没有标准替代品.
There is no standard replacement in C++.
在Linux(以及类似的系统,例如BSD)上,有一个遗留函数 getpass
,建议不要使用它.我之所以提及它,是因为glibc中该函数的文档建议以下:
Linux (and similar systems such as BSD), there is a legacy function getpass
whose use is not recommended. I mention it because the documentation of that function in glibc suggests following:
#include <termios.h>
#include <stdio.h>
ssize_t
my_getpass (char **lineptr, size_t *n, FILE *stream)
{
struct termios old, new;
int nread;
/* Turn echoing off and fail if we can’t. */
if (tcgetattr (fileno (stream), &old) != 0)
return -1;
new = old;
new.c_lflag &= ~ECHO;
if (tcsetattr (fileno (stream), TCSAFLUSH, &new) != 0)
return -1;
/* Read the passphrase */
nread = getline (lineptr, n, stream);
/* Restore terminal. */
(void) tcsetattr (fileno (stream), TCSAFLUSH, &old);
return nread;
}
请注意,该示例是用C编写的,并且不是有效的C ++.需要进行一些小的更改,尤其是将C ++关键字 new
用作变量名.只需将其重命名为其他名称即可.
Note that the example is written in C, and is not valid C++. Small changes are required, in particular there is a C++ keyword new
being used as a variable name. Simply rename it to something else.
还请注意,该行为是完全不回显,而不是回显 *
.这在POSIX系统中是常规的,并且更安全,因为它不会显示密码短语的长度.
Also note that the behaviour is to not echo at all, rather than echo *
. This is conventional in POSIX systems, and safer because the it does not reveal the length of the passphrase.
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