What's the best way to check if a file exists in C?

Question

Is there a better way than simply trying to open the file?

int exists(const char *fname)
{
    FILE *file;
    if ((file = fopen(fname, \"r\")))
    {
               


        

Answer 1

From the Visual C++ help, I'd tend to go with

/* ACCESS.C: This example uses _access to check the
 * file named "ACCESS.C" to see if it exists and if
 * writing is allowed.
 */

#include  
#include  
#include  

void main( void )
{
   /* Check for existence */
   if( (_access( "ACCESS.C", 0 )) != -1 )
   {
      printf( "File ACCESS.C exists\n" );
      /* Check for write permission */
      if( (_access( "ACCESS.C", 2 )) != -1 )
         printf( "File ACCESS.C has write permission\n" );
   }
}

Also worth noting mode values of _access(const char *path,int mode):

• 00: Existence only

• 02: Write permission

• 04: Read permission

• 06: Read and write permission

As your fopen could fail in situations where the file existed but could not be opened as requested.

Edit: Just read Mecki's post. stat() does look like a neater way to go. Ho hum.