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stdio.c

/*
 * Copyright (C) Paul Mackerras 1997.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */
#include <stdarg.h>
#include <stddef.h>
#include "string.h"
#include "stdio.h"
#include "ops.h"

size_t strnlen(const char * s, size_t count)
{
      const char *sc;

      for (sc = s; count-- && *sc != '\0'; ++sc)
            /* nothing */;
      return sc - s;
}

extern unsigned int __div64_32(unsigned long long *dividend,
                         unsigned int divisor);

/* The unnecessary pointer compare is there
 * to check for type safety (n must be 64bit)
 */
# define do_div(n,base) ({                                  \
      unsigned int __base = (base);                         \
      unsigned int __rem;                                   \
      (void)(((typeof((n)) *)0) == ((unsigned long long *)0));    \
      if (((n) >> 32) == 0) {                               \
            __rem = (unsigned int)(n) % __base;             \
            (n) = (unsigned int)(n) / __base;               \
      } else                                                \
            __rem = __div64_32(&(n), __base);               \
      __rem;                                                \
 })

static int skip_atoi(const char **s)
{
      int i, c;

      for (i = 0; '0' <= (c = **s) && c <= '9'; ++*s)
            i = i*10 + c - '0';
      return i;
}

#define ZEROPAD   1           /* pad with zero */
#define SIGN      2           /* unsigned/signed long */
#define PLUS      4           /* show plus */
#define SPACE     8           /* space if plus */
#define LEFT      16          /* left justified */
#define SPECIAL   32          /* 0x */
#define LARGE     64          /* use 'ABCDEF' instead of 'abcdef' */

static char * number(char * str, unsigned long long num, int base, int size, int precision, int type)
{
      char c,sign,tmp[66];
      const char *digits="0123456789abcdefghijklmnopqrstuvwxyz";
      int i;

      if (type & LARGE)
            digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
      if (type & LEFT)
            type &= ~ZEROPAD;
      if (base < 2 || base > 36)
            return 0;
      c = (type & ZEROPAD) ? '0' : ' ';
      sign = 0;
      if (type & SIGN) {
            if ((signed long long)num < 0) {
                  sign = '-';
                  num = - (signed long long)num;
                  size--;
            } else if (type & PLUS) {
                  sign = '+';
                  size--;
            } else if (type & SPACE) {
                  sign = ' ';
                  size--;
            }
      }
      if (type & SPECIAL) {
            if (base == 16)
                  size -= 2;
            else if (base == 8)
                  size--;
      }
      i = 0;
      if (num == 0)
            tmp[i++]='0';
      else while (num != 0) {
            tmp[i++] = digits[do_div(num, base)];
      }
      if (i > precision)
            precision = i;
      size -= precision;
      if (!(type&(ZEROPAD+LEFT)))
            while(size-->0)
                  *str++ = ' ';
      if (sign)
            *str++ = sign;
      if (type & SPECIAL) {
            if (base==8)
                  *str++ = '0';
            else if (base==16) {
                  *str++ = '0';
                  *str++ = digits[33];
            }
      }
      if (!(type & LEFT))
            while (size-- > 0)
                  *str++ = c;
      while (i < precision--)
            *str++ = '0';
      while (i-- > 0)
            *str++ = tmp[i];
      while (size-- > 0)
            *str++ = ' ';
      return str;
}

int vsprintf(char *buf, const char *fmt, va_list args)
{
      int len;
      unsigned long long num;
      int i, base;
      char * str;
      const char *s;

      int flags;        /* flags to number() */

      int field_width;  /* width of output field */
      int precision;          /* min. # of digits for integers; max
                           number of chars for from string */
      int qualifier;          /* 'h', 'l', or 'L' for integer fields */
                              /* 'z' support added 23/7/1999 S.H.    */
                        /* 'z' changed to 'Z' --davidm 1/25/99 */

      
      for (str=buf ; *fmt ; ++fmt) {
            if (*fmt != '%') {
                  *str++ = *fmt;
                  continue;
            }
                  
            /* process flags */
            flags = 0;
            repeat:
                  ++fmt;            /* this also skips first '%' */
                  switch (*fmt) {
                        case '-': flags |= LEFT; goto repeat;
                        case '+': flags |= PLUS; goto repeat;
                        case ' ': flags |= SPACE; goto repeat;
                        case '#': flags |= SPECIAL; goto repeat;
                        case '0': flags |= ZEROPAD; goto repeat;
                        }
            
            /* get field width */
            field_width = -1;
            if ('0' <= *fmt && *fmt <= '9')
                  field_width = skip_atoi(&fmt);
            else if (*fmt == '*') {
                  ++fmt;
                  /* it's the next argument */
                  field_width = va_arg(args, int);
                  if (field_width < 0) {
                        field_width = -field_width;
                        flags |= LEFT;
                  }
            }

            /* get the precision */
            precision = -1;
            if (*fmt == '.') {
                  ++fmt;      
                  if ('0' <= *fmt && *fmt <= '9')
                        precision = skip_atoi(&fmt);
                  else if (*fmt == '*') {
                        ++fmt;
                        /* it's the next argument */
                        precision = va_arg(args, int);
                  }
                  if (precision < 0)
                        precision = 0;
            }

            /* get the conversion qualifier */
            qualifier = -1;
            if (*fmt == 'l' && *(fmt + 1) == 'l') {
                  qualifier = 'q';
                  fmt += 2;
            } else if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L'
                  || *fmt == 'Z') {
                  qualifier = *fmt;
                  ++fmt;
            }

            /* default base */
            base = 10;

            switch (*fmt) {
            case 'c':
                  if (!(flags & LEFT))
                        while (--field_width > 0)
                              *str++ = ' ';
                  *str++ = (unsigned char) va_arg(args, int);
                  while (--field_width > 0)
                        *str++ = ' ';
                  continue;

            case 's':
                  s = va_arg(args, char *);
                  if (!s)
                        s = "<NULL>";

                  len = strnlen(s, precision);

                  if (!(flags & LEFT))
                        while (len < field_width--)
                              *str++ = ' ';
                  for (i = 0; i < len; ++i)
                        *str++ = *s++;
                  while (len < field_width--)
                        *str++ = ' ';
                  continue;

            case 'p':
                  if (field_width == -1) {
                        field_width = 2*sizeof(void *);
                        flags |= ZEROPAD;
                  }
                  str = number(str,
                        (unsigned long) va_arg(args, void *), 16,
                        field_width, precision, flags);
                  continue;


            case 'n':
                  if (qualifier == 'l') {
                        long * ip = va_arg(args, long *);
                        *ip = (str - buf);
                  } else if (qualifier == 'Z') {
                        size_t * ip = va_arg(args, size_t *);
                        *ip = (str - buf);
                  } else {
                        int * ip = va_arg(args, int *);
                        *ip = (str - buf);
                  }
                  continue;

            case '%':
                  *str++ = '%';
                  continue;

            /* integer number formats - set up the flags and "break" */
            case 'o':
                  base = 8;
                  break;

            case 'X':
                  flags |= LARGE;
            case 'x':
                  base = 16;
                  break;

            case 'd':
            case 'i':
                  flags |= SIGN;
            case 'u':
                  break;

            default:
                  *str++ = '%';
                  if (*fmt)
                        *str++ = *fmt;
                  else
                        --fmt;
                  continue;
            }
            if (qualifier == 'l') {
                  num = va_arg(args, unsigned long);
                  if (flags & SIGN)
                        num = (signed long) num;
            } else if (qualifier == 'q') {
                  num = va_arg(args, unsigned long long);
                  if (flags & SIGN)
                        num = (signed long long) num;
            } else if (qualifier == 'Z') {
                  num = va_arg(args, size_t);
            } else if (qualifier == 'h') {
                  num = (unsigned short) va_arg(args, int);
                  if (flags & SIGN)
                        num = (signed short) num;
            } else {
                  num = va_arg(args, unsigned int);
                  if (flags & SIGN)
                        num = (signed int) num;
            }
            str = number(str, num, base, field_width, precision, flags);
      }
      *str = '\0';
      return str-buf;
}

int sprintf(char * buf, const char *fmt, ...)
{
      va_list args;
      int i;

      va_start(args, fmt);
      i=vsprintf(buf,fmt,args);
      va_end(args);
      return i;
}

static char sprint_buf[1024];

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

      va_start(args, fmt);
      n = vsprintf(sprint_buf, fmt, args);
      va_end(args);
      if (console_ops.write)
            console_ops.write(sprint_buf, n);
      return n;
}

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