What Type of Pointer is FILE *p?

1. Definition

FILE is a file type predefined in stdio.h.

You must first declare a file pointer variable and then operate on it using file functions.
In textbooks, you may have seen the FILE type defined as:

typedef struct{  
short level; /* degree of "full/empty" in buffer */  
unsigned flags; /* file status flags */  
char fd;  
unsigned char hold;  
short bsize; /* buffer size */  
unsigned char *buffer; /* location of data buffer */  
unsigned char *curp; /* pointer to current read/write position */  
unsigned istemp;  
short token;  
}FILE;

FILE is a structure pointer that contains information such as the file name, file buffer, and so on.

2. Initialization

FILE *fpt = fopen("a.txt", "r");

3. Program Example

#include <stdio.h>
int main(void)
{
    FILE *stream;
    /* open a file for reading */
    stream = fopen("DUMMY.FIL", "r");
    /* read a character from the file */
    fgetc(stream);
    /* check for EOF */
    if (feof(stream))
        printf("We have reached end-of-file\n");
    /* close the file */
    fclose(stream);
    return 0;
}