read to memory

2memory.c

/*
	A demo of reading the entire contents of a file. Other than
	"echoing" the contents of the file to the console this program
	does do anything useful.
	
	The program assumes we have a file called test.dat in the same
	directory as the executible.

	M. Kesson
	4.12.03
  http://www.fundza.com/c4serious/fileIO_reading_all/
*/

#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>

int main(void)
{
/* declare a file pointer */
FILE    *infile;
char    *buffer;
long    numbytes;
 
/* open an existing file for reading */
infile = fopen("test.dat", "r");
 
/* quit if the file does not exist */
if(infile == NULL)
    return 1;
 
/* Get the number of bytes */
fseek(infile, 0L, SEEK_END);
numbytes = ftell(infile);
 
/* reset the file position indicator to 
the beginning of the file */
fseek(infile, 0L, SEEK_SET);	
 
/* grab sufficient memory for the 
buffer to hold the text */
buffer = (char*)calloc(numbytes, sizeof(char));	
 
/* memory error */
if(buffer == NULL)
    return 1;
 
/* copy all the text into the buffer */
fread(buffer, sizeof(char), numbytes, infile);
fclose(infile);

/* confirm we have read the file by
outputing it to the console */
printf("The file called test.dat contains this text\n\n%s", buffer);

/* free the memory we used for the buffer */
free(buffer);
 
return 0;
}