求助 c 程序fopen 写一个文件 出来很多“屯”

Question

代码：
#include "stdafx.h"
#include
#include
using namespace std;
char *ReadALine(char *buf, int n, FILE *fp)
{
char ch;
int i = 0;
ch = fgetc(fp);
while (ch != EOF)
{
if ((ch == '\n') || (ch == '\r'))
{
buf[i++] = '\0';
break;
}
else if (i == n - 1)
{
buf[i] = '\0';
break;

    }
    else
    {
        buf[i++] = ch;
    }
}
return buf;

}

int _tmain(int argc, _TCHAR* argv[])
{
char buf[30];
memset(buf, 0, sizeof(buf));
char ch;
FILE *fp = fopen("C:\test.txt", "w");
if (fp == NULL)
{
return 0;
fclose(fp);
}
fputs("Hello,world!\n", fp);
fputs("Hello,UESTC!\n", fp);
cout << "文件内容：" << endl;
while ((ch = fgetc(fp) != EOF))
{
cout << ch;
}
cout << endl;
fclose(fp);

FILE *testfp = fopen("C:\\test.txt", "r");


ReadALine(buf, 20, testfp);
cout << buf;
cout << endl;
fclose(testfp);

system("pause");
return 0;

}

Answer 1

你开的内存空间太大，写入 的内容太少。