check if the file exists

how do i check if a file exist?

without using if (fopen(....));

Im not sure if there is a function that does this. But this would work using fopen.

Code:

---

#include <stdio.h>

int
main(void)
{

        if (fopen("filename.txt", "r") == NULL) {
                printf("You know the file doesn't exist\n");
        }
        else {
                printf("File exists\n");
        }

        return (0);
}

---

fopen returns NULL on error, and a FILE pointer on success. So in this case if fopen returns NULL you know that there is no file, otherwise fopens returns a FILE pointer and nothing happens. If your still confused you can read here to learn more about fopen and about how it works.

>how do i check if a file exist?
The only portable way is to try and open it for reading. If the operation fails then it's a good bet that the file doesn't exist.

>without using if (fopen(....));
In that case, it depends on your operating system and compiler, for example, this would work if your system supports it:

Code:

---

#include <sys/stat.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>

int main ( void )
{
  struct stat buf;

  errno = 0;
  if ( stat ( "somefilename", &buf ) != 0 && errno == ENOENT ) {
    fprintf ( stderr, "File or file path does not exist\n" );
    exit ( EXIT_FAILURE );
  }

  return EXIT_SUCCESS;
}

---

-Prelude