readfile.h

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

///////////////////////////////////////////////////////////
// Read File
///////////////////////////////////////////////////////////
char *readFile(char *input)
{
    char *source = NULL;

    FILE *fp = fopen(input, "r");
    if (fp != NULL)
    {
        /* Go to the end of the file. */
        if (fseek(fp, 0L, SEEK_END) == 0)
        {
            /* Get the size of the file. */
            long bufsize = ftell(fp);
            if (bufsize == -1)
            { /* Error */
            }

            /* Allocate our buffer to that size. */
            source = malloc(sizeof(char) * (bufsize + 1));

            /* Go back to the start of the file. */
            if (fseek(fp, 0L, SEEK_SET) != 0)
            { /* Error */
            }

            /* Read the entire file into memory. */
            size_t newLen = fread(source, sizeof(char), bufsize, fp);
            if (ferror(fp) != 0)
            {
                fputs("Error reading file", stderr);
            }
            else
            {
                source[newLen++] = '\0'; /* Just to be safe. */
            }
        }
        fclose(fp);
    }

    return source;
}