Linux 有些人对帕斯卡的输出感到迷惑不解

平台：Linux 2.6.18 x86_64

编译器：用于x86_64的免费Pascal编译器版本2.2.2[2008/11/05]

源代码是：

Program main;
var invalue:string;
Begin
        (*Until the EOF, this loop continue to work*)
        while not eof do
        begin
                Write('Please input the express: ');
                Flush(StdOut);
                Readln(invalue);
                Writeln('The expression is: ',invalue);
        end;
        Writeln('');
        Writeln('Exit the program. Bye!');
End.

我编译并运行了它。但输出类似于：

123
Please input the express: The expression is: 123
234
Please input the express: The expression is: 234
345
Please input the express: The expression is: 345

Exit the program. Bye!

这些数字是我的输入。我在谷歌上搜索了一下，认为这是因为缓冲区。因此，我尝试在写入之后添加flushstdout或flushoutput。但它仍然不能很好地工作

我希望它的作用如下：

Please input the express: 123
The expression is: 123
Please input the express: 234
The expression is: 234
Please input the express: 345
The expression is: 345

Exit the program. Bye!

谢谢大家!！为我的傻瓜感到抱歉~

补充： 我试着谢谢你，阿卢什

Program main;
var invalue:string;
Begin
        (*Until the EOF, this loop continue to work*)
        while not eof do
        begin
                Write('Please input the express: ');
                Flush(StdOut);
                Readln(invalue);
                Writeln('')
                Writeln('The expression is: ',invalue);
        end;
        Writeln('');
        Writeln('Exit the program. Bye!');
End.

结果仍然不尽如人意：

1
Please input the express: 
The expression is: 1
2
Please input the express: 
The expression is: 2
3
Please input the express: 
The expression is: 3
4
Please input the express: 
The expression is: 4
5
Please input the express: 
The expression is: 5

Exit the program. Bye!

Readln仍在第一次写入之前执行

顺便说一下，我还尝试：

Program main;
var invalue:string;
Begin
        (*Until the EOF, this loop continue to work
        while not eof do
        begin*)
        Repeat
                Write('Please input the express: ');
                Flush(StdOut);
                Readln(invalue);
                Writeln('The expression is: ',invalue);
        Until eof;
        Writeln('');
        Writeln('Exit the program. Bye!');
End.

在这种情况下，第一个循环是好的，但其他循环仍然是错误的

Please input the express: 123
The expression is: 123
234
Please input the express: The expression is: 234
345
Please input the express: The expression is: 345

Exit the program. Bye!

谢谢大家!

最终解决方案： 这是因为，eof实际上对应于隐式读取。 当前代码应为：

Program main;
var invalue:string;
Begin
        (*Until the EOF, this loop continue to work*)
        Write('Please input the express: ');
        while not Eof  do
        begin
                Readln(invalue);
                Writeln('The expression is: ',invalue);
                Write('Please input the express: ');
        end;
        Writeln('');
        Writeln('Exit the program. Bye!');
End.

---

最后，谢谢你，阿卢什和凯伊在CSDN

你能试试下面的方法吗

Program main;
var invalue:string;
Begin
        (*Until the EOF, this loop continue to work*)
        while not eof do
        begin
                Write('Please input the express: ');
                Flush(StdOut);
                Readln(invalue);
                Writeln('')
                Writeln('The expression is: ',invalue);
        end;
        Writeln('');
        Writeln('Exit the program. Bye!');
End.

---

请勾选答案左边的箭头，将其标记为已接受。这比编辑要解决的标题要好。