Reputation: 67

Runtime error during file operation in C

I am trying to run a C code for file opening and whenever I do that I get a debug assertion failed message.

Here is my code:

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

void main()
{
    FILE *fp1;
    printf("program to demonstrate file operations");
    fp1 = fopen("try1.txt","r");
    if (feof(fp1))
    {
        printf("Yes");
    }
    else 
        printf("No");

    printf("%f",fp1);

    getchar();
}

Upvotes: 0

Answers (5)

Saurabh Meshram

Reputation: 8436

Before using feof() on fp.
Ensure that fopen() succeeded.

#include <string.h>   /* For strerror() */
#include <errno.h>    /* For errno  */
#include <stdlib.h>   /* For exit() */

fp = fopen ("FaultyFile.txt", "r");

/* Add Error-checking */             
if (NULL == fp)                          
{
    printf ("Error No : [%d]\n", errno);
    printf ("Error Msg: [%s]\n", strerror(errno));
    exit (EXIT_FAILURE);          
}

From man(3) fopen:
Return Value: Upon successful fopen() return a FILE pointer. Otherwise, NULL is returned and errno is set to indicate the error.

Upvotes: 0

Saisujithreddy

Reputation: 92

Try to check if the file is opened correctly or not
check if( fp==NULL) using an if condition

if fp==NULL is true, file is not being opened correctly

Upvotes: 0

jjm

Reputation: 461

Check the return value of

 fp1 = fopen("try1.txt","r");

first. It is fare to check the return values of all standard functions( with proper return values) before proceeding to next step. In this case "fp1" should not be NULL. Please check the file location or check whether file is present in current directory.

Upvotes: 0