/*
    In this example we demonstrate how to pass a pointer to a file pointer as
    function parameter
*/
#include <conio.h> // for getch()
#include <stdio.h> // for FILE,fopen(),fclose & printf()

/*
    This program examines whether a file exists.
*/

/*
    Function prototype. Notice the FILE ** declareation
*/
int openfile( FILE **, char *, char *);

void main(void)
{
    FILE *fp; /* File pointer variable */
    char s[128];
    printf("Please type the filename to check : ");
    scanf("%s",s);
    if (openfile( &fp, s, "r" ))
    {
        fclose(fp);
        printf("OK. The file %s exists.\n",s);
    }
    else
        printf("The file %s does not exist.\n",s);
    getch();
}

/*
    Function openfile source code.
*/
int openfile( FILE ** fpp, char *n, char *m )
{
    return ( *fpp = fopen( n, m ) ) != NULL;
}

© 2004 Jim Valavanis