myprintf.c
author Markus Bröker<broeker.markus@googlemail.com>
Sun, 22 Oct 2017 22:55:27 +0200
changeset 172 43ae72f88d06
parent 77 49e0babccb23
permissions -rw-r--r--
2er Komplement und integerToString

/**
 * myprintf.c
 * Copyright (C) 2008 Markus Broeker
 */

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

#define BUF_SIZE 1024

int myvfprintf (FILE * fp, const char *fmt, va_list list)
{
    int i, value, pos = 0, size = 1;
    char c;

    char *ptr;
    char *s;
    char *s_str;
    char v_str[28];

    if ((s_str = malloc (BUF_SIZE)) == NULL) {
        return EOF;
    }

    while (*fmt) {
        switch (*fmt) {
        case '%':
            switch (*++fmt) {
            case 'c':
                c = va_arg (list, int);
                s_str[pos++] = c;
                break;

            case 's':
                s = va_arg (list, char *);
                while ((pos + strlen (s)) > (size * BUF_SIZE)) {
                    if ((ptr = realloc (s_str, ++size * BUF_SIZE)) == NULL) {
                        s_str[pos] = '\0';
                        fputs (s_str, fp);  /* print it anyway... */
                        free (s_str);
                        return EOF;
                    }
                    s_str = ptr;
                }
                for (i = 0; i < strlen (s); i++) {
                    s_str[pos++] = s[i];
                }
                break;

            case 'd':
                value = va_arg (list, int);
                sprintf (v_str, "%d", value);
                for (i = 0; i < strlen (v_str); i++) {
                    s_str[pos++] = v_str[i];
                }
                break;

            default:
                s_str[pos++] = *fmt;
            }

            c = *fmt++;
        default:
            s_str[pos++] = *fmt++;
        }

        if (pos > (size * BUF_SIZE / 2)) {
            if ((ptr = realloc (s_str, ++size * BUF_SIZE)) == NULL) {
                free (s_str);
                return EOF;
            }
            s_str = ptr;
        }
    }

    va_end (list);

    s_str[pos] = '\0';
    fputs (s_str, fp);
    free (s_str);

    return pos;
}

int myfprintf (FILE * fp, const char *fmt, ...)
{
    va_list list;
    int ret;

    va_start (list, fmt);
    ret = myvfprintf (fp, fmt, list);
    va_end (list);

    return ret;
}

int myprintf (const char *fmt, ...)
{
    va_list list;
    int ret;

    va_start (list, fmt);
    ret = myvfprintf (stdout, fmt, list);
    va_end (list);

    return ret;
}

int main (int argc, char **argv)
{
    int len;

    len = myprintf ("Printf replacement %% [Version %d - %s]...\n", 5, "LSF Rostock");

    return EXIT_SUCCESS;
}