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


#define MAXSTR 80

static int do_printf( int (*)( int), const char *, va_list);
static void pr_int( unsigned long, int, char *);


void
printf( const char *fmt, ...) {
    va_list args;

    va_start(args, fmt);
    do_printf(putchar, fmt, args);
    va_end(args);
}

static int
do_printf( int ( *func)(int), const char *fmt, va_list ap) {
    int         i;
    char        *str;
    char        string[20];
    int         length;
    int         leftjust;
    int         longflag;
    int         fmax, fmin;
    int         leading;
    int         outcnt;
    char        fill;
    char        sign;

    outcnt = 0;
    while ( ( i = *fmt++) != '\0') {
        if ( i != '%') {
            (*func)(i);
            outcnt += 1;
            continue;
        }
        if ( *fmt == '%') {
            (*func)(*fmt++);
            outcnt += 1;
            continue;
        }
        leftjust = ( *fmt == '-');
        if ( leftjust)
            fmt++;
        fill = ( *fmt == '0') ? *fmt++ : ' ';
        if ( *fmt == '*')
            fmin = va_arg(ap, int);
        else {
            fmin = 0;
            while ( '0' <= *fmt && *fmt <= '9')
                fmin = fmin * 10 + *fmt++ - '0';
        }
        if ( *fmt != '.')
            fmax = 0;
        else {
            fmt++;
            if ( *fmt == '*')
                fmax = va_arg(ap, int);
            else {
                fmax = 0;
                while ( '0' <= *fmt && *fmt <= '9')
                    fmax = fmax * 10 + *fmt++ - '0';
            }
        }
        longflag = ( *fmt == 'l');
        if ( longflag)
            fmt++;
        if ( ( i = *fmt++) == '\0') {
            ( *func)('%');
            outcnt += 1;
            break;
        }
        str = string;
        sign = ' ';
        switch (i) {
        case 'c':
            str[0] = va_arg( ap, int);
            str[1] = '\0';
            fmax = 0;
            fill = ' ';
            break;

        case 's':
            str = va_arg( ap, char *);
            fill = ' ';
            break;

        case 'd':
              {
            long l = va_arg( ap, long);
            if (l < 0) { sign = '-' ; l = -l; }
            pr_int( ( unsigned long)l, 10, str);
              }
            break;

        case 'u':
            pr_int( va_arg( ap, unsigned long), 10, str);
            break;

        case 'o':
            pr_int( va_arg( ap, unsigned long), 8, str);
            fmax = 0;
            break;

        case 'X':
        case 'x':
            pr_int( va_arg( ap, unsigned long), 16, str);
            fmax = 0;
            break;

        case 'p':
            pr_int( va_arg( ap, unsigned long), 16, str);
            fill = '0';
            fmin = 8;
            fmax = 0;
            ( *func)('0'); ( *func)('x');
            outcnt += 2;
            break;
        default:
            ( *func)(i);
            break;
        }
        for ( i = 0; str[i] != '\0'; i++) ;
        length = i;
        if ( fmin > MAXSTR || fmin < 0)
            fmin = 0;
        if ( fmax > MAXSTR || fmax < 0)
            fmax = 0;
        leading = 0;
        if ( fmax != 0 || fmin != 0) {
            if ( fmax != 0 && length > fmax)
                length = fmax;
            if ( fmin != 0)
                leading = fmin - length;
            if ( sign == '-')
                --leading;
        }
        outcnt += leading + length;
        if ( sign == '-')
            outcnt += 1;
        if ( sign == '-' && fill == '0')
            (*func)(sign);
        if ( leftjust == 0)
            for (i = 0; i < leading; i++) (*func)(fill);
        if ( sign == '-' && fill == ' ')
            (*func)(sign);
        for ( i = 0; i < length; i++)
            (*func)(str[i]);
        if ( leftjust != 0)
            for (i = 0; i < leading; i++) (*func)(fill);
    }
    return outcnt;
}


static void
pr_int( unsigned long lval, int base, char *s) {
    char                ptmp[12];   /* unsigned long requires 11 digit in octal form */
    int                 i = 1;
    char                *t = ptmp;
    static const char   hexdigit[] = "0123456789abcdef";

    *t++ = '\0';
    do {
        *t++ = hexdigit[lval % base];
    } while ( ( lval /= base) != 0 && ++i < sizeof( ptmp));

    while ( ( *s++ = *--t) != '\0')
        ;
}