Simple fopen and fprintf not working

问题

I have a simple program which opens a file and write a text into the file. However, the fopen is always returning BadPtr as seen in debug mode in Microsoft Visual c++, 2010.

Below is the warning that is displayed in VS C++, 2010:

mysample\mysample\main.c(6): warning C4996: 'fopen': This function or variable may be unsafe. Consider using fopen_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.
1>          c:\program files\microsoft visual studio 10.0\vc\include\stdio.h(234) : see declaration of 'fopen'

I thought the warning is a problem and used fopen_s, however this also doesnt solve the problem. Below is my code:

#include <stdio.h>

int main()
{
    FILE *fp;
    fp=fopen("c:\\hello.txt","w+");

    if(fp==NULL)
    {
        printf("\nfopen() error\n");
        return 1;
    }
    else
    {
        fprintf(fp,"\nThis is a sample text file\n");
    }

    fclose(fp);
    return 0;
}

In the above code, the flow doesn't enter the if(fp == NULL) condition, rather it goes to the else part, but the file is not being created.

Please help regarding the same.

回答1:

If you do not have admin privileges

Create file in you compilation directory

fp=fopen("hello.txt","w+");

This will create file in mysample\mysample

You should have admin privileges, to create file in C:\

if you have admin privileges open command Prompt with Run as Administator and then execute your executable by just giving name.

if you use filename fopen.c, you will get fopen.exe

simply run fopen from command prompt, it will create file in C:\

回答2:

Your code works, but if you want create the file in C:\ you need Admin Privileges, try saving the file in the same file directory of your program, or run an Administrator cmd and execute your *.exe there.

来源：https://stackoverflow.com/questions/19330987/simple-fopen-and-fprintf-not-working

标签

c++

fopen