gists/c-programming/jokes/extol.modern.c

/*
 * extol.modern.c [joke!]
 *
 * A modern C version of extol.c
 *
 * Author: Intel A80486DX2-66
 * License: Creative Commons Zero 1.0 Universal
 */

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

enum
{
    EXTOL_NORMAL,
    EXTOL_QUIET
} EXTOL_MODE;

#define EXTOL_PROTOTYPE "int extol(FILE* file)"
#define EXTOL_FILE_NAME "extol.txt"
#define EXTOL_FILE_LIMIT 128

int extol(FILE *file);
int extol_interface(int type);
void extol_quiet(void);

int extol(FILE *file)
{
    static bool spec_run = true;
    int result;
    off_t size;

    if (spec_run == false)
    {
        printf("\n");
        return !(spec_run = true) - spec_run;
    }

    if (file == NULL)
    {
        FILE *file_handler = fopen(EXTOL_FILE_NAME, "a");
        if (file_handler == NULL)
        {
            perror("fopen");
            exit(EXIT_FAILURE);
        }
        fseek(file_handler, 0L, SEEK_END);
        size = ftello(file_handler);
        if (size == -1)
        {
            perror("ftello");
            exit(EXIT_FAILURE);
        }
        else if (size > EXTOL_FILE_LIMIT)
        {
            FILE *new_file_handler =
                freopen(EXTOL_FILE_NAME, "w", file_handler);
            if (new_file_handler == NULL)
            {
                perror("freopen");
                exit(EXIT_FAILURE);
            }
            file_handler = new_file_handler;
        }
        result = extol(file_handler);
        for (uint_fast8_t i = 0; i < 16; i++)
            fputc('=', file_handler);
        fprintf(file_handler, "\n");
        fclose(file_handler);
    }
    else
    {
        result = fprintf(file, "PRAISE THE USER!\n");
    }
    spec_run = false;
    return result;
}

int extol_interface(int type)
{
    return printf(EXTOL_PROTOTYPE " returns %d\n",
                  extol(type == EXTOL_NORMAL ? stdout : NULL));
}

void extol_quiet(void)
{
    extol_interface(EXTOL_QUIET);
}

int main(void)
{
    for (uint_fast8_t i = 0; i < 2; i++)
        printf(EXTOL_PROTOTYPE ": %d\n", extol_interface(EXTOL_NORMAL));
    atexit(&extol_quiet);
    return 0;
}