Question

我是C编程新手，我试图创建一个程序来读取名为input的文件的上下文。

#include <stdio.h>
#include <stdlib.h>

int main()
{
    char ch;
    FILE *in;
    in = fopen("input","r");
    printf("The contents of the file are\n");
    fscanf(in,"%c",&ch);
    printf("%c",ch);
    fclose(in);
    return 0;
}

Answer 1

您的代码只读取文件的第一个字符。没有循环来读取整个文件。那是你的意图吗？

另外，检查文件是否成功打开。是输入文件名＆＃34;输入＆＃34; ？

Answer 2

试试这个 -

java.util.Date objDt1 = getDate1FromSrc1();  // I am obtaining it from src1
java.util.Date objDt2 = getDate2FromOtherSrc(); // I am getting dt2 by other way.

Answer 3

假设文件input的内容为：

Hello World

您可以尝试以下代码：

#include <stdio.h>
#include <stdlib.h>

int main()
{
    char ch;
    FILE *in;
    in = fopen("input","r");
    printf("The contents of the file are\n");
    while(fscanf(in, "%c", &ch) != EOF)
    {
        printf("%c",ch);
    }
    fclose(in);
    return 0;
}

<强>输出：

The contents of the file are
Hello World

Answer 4

你应该用这个：

#include <stdio.h>
#include <stdlib.h>

int main()
{
    char ch;
    FILE *in;

    /*Don't forget the extension (.txt)*/
    if(in = fopen("input.txt","r") == NULL);     
    {
        printf("File could not be opened\n");
    }
    else                                 
    {
       printf("The contents of the file are\n");
       /*I assume that you are reading char types*/
       fscanf(in,"%c",&ch);                   

       /*Check end-of-file indicator*/
       while(!feof(in))                      
       {
           printf("%c",ch);
           fscanf(in,"%c",&ch); 
       }
    }

    fclose(in);
    return 0;
}

你应该记住验证文件是否开放，这总是一个好习惯。

为什么我的C程序不起作用？从文件中读取

4 个答案: