How do I know if a file exists in C?

Question

How would I know if a file exists in my current directory in C? I'm prompting the user and I'm trying to see if the file they type in already exists or not. Here's what I got:

int a=0;
char ing[100];
FILE * inp;


while (a=0);
{
    printf("Input file name: ");
    scanf("%s", ing);
    inp=fopen(ing , "r");
        if (inp==NULL)
            a=0;
        else
            a=1;
}

Whenever I type in a file that doesn't exist, I get that the cmd isn't responding. Whenever I type something that exists, it works fine, which is good. I just don't know what exactly I would need to put in if NULL doesn't work.

possible duplicate of [What's the best way to check if a file exists in C? (cross platform)](http://stackoverflow.com/questions/230062/whats-the-best-way-to-check-if-a-file-exists-in-c-cross-platform) — notadam, Mar 27 '15 at 22:44

score 1 · Answer 1 · answered Mar 27 '15 at 22:45

1

Replace:

while (a=0)

With:

while (a==0)

And for the check use this:

if( access( ing, F_OK ) != -1 ) {
    // exists
} else {
    // not exist
}

answered Mar 27 '15 at 22:45

ismaestro

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score 1 · Answer 2 · answered Mar 28 '15 at 04:12

Using a access() function in c , we can get to know the existence of the file and permission allocated for us. for the file.

  if(access(filename,Checking option)==0)
             printf("success\n");
   else
     printf("...\n");

Checking option:

     R_OK - Check for the read operation
     W_OK - check for the write operation
     X_OK - check for the execute operation
     F_OK - check for the existence of the file

How do I know if a file exists in C?

2 Answers2

Checking option: