glibc/stdlib/strfmon.c

/* strfmon -- formating a monetary value according to the current locale
Copyright (C) 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>
and Jochen Hein <Jochen.Hein@informatik.TU-Clausthal.de>, 1996.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include <ctype.h>
#include <errno.h>
#include <langinfo.h>
#include <monetary.h>
#ifdef USE_IN_LIBIO
# include "../libio/libioP.h"
# include "../libio/strfile.h"
#endif
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include "../stdio-common/printf.h"
#include "../locale/localeinfo.h"


#define out_char(Ch)							      \
  do {									      \
    if (dest >= s + maxsize - 1)					      \
      {									      \
	errno = E2BIG;							      \
	va_end (ap);							      \
	return -1;							      \
      }									      \
    *dest++ = (Ch);							      \
  } while (0)

#define out_string(String)						      \
  do {									      \
    const char *_s = (String);						      \
    while (*_s)								      \
      out_char (*_s++);							      \
  } while (0)

#define to_digit(Ch) ((Ch) - '0')

extern int __printf_fp (FILE *, const struct printf_info *,
			const void **const);
/* This function determines the number of digit groups in the output.
   The definition is in printf_fp.c.  */
extern unsigned int __guess_grouping (unsigned int intdig_max,
				      const char *grouping, wchar_t sepchar);


/* We have to overcome some problems with this implementation.  On the
   one hand the strfmon() function is specified by in XPG4 and of
   course it has to follow this.  But on the other hand POSIX.2
   specifies some information in the LC_MONETARY category which should
   be used, too.  Some of the information contradicts the information
   which can be specified in format string.  */
ssize_t
strfmon (char *s, size_t maxsize, const char *format, ...)
{
#ifdef USE_IN_LIBIO
  _IO_strfile f;
#else
  FILE f;
#endif
  struct printf_info info;
  va_list ap;			/* Scan through the varargs.  */
  char *dest;			/* Pointer so copy the output.  */
  const char *fmt;		/* Pointer that walks through format.  */

  va_start (ap, format);

  dest = s;
  fmt = format;

  /* Loop through the format-string.  */
  while (*fmt != '\0')
    {
      /* The floating-point value to output.  */
      union
      {
	double dbl;
	__long_double_t ldbl;
      }
      fpnum;
      int print_curr_symbol;
      int left_prec;
      int right_prec;
      int group;
      char pad;
      int is_long_double;
      int p_sign_posn;
      int n_sign_posn;
      int sign_posn;
      int left;
      int is_negative;
      int sep_by_space;
      int cs_precedes;
      char sign_char;
      int done;
      const char *currency_symbol;
      int width;
      char *startp;
      const void *ptr;

      /* Process all character which do not introduce a format
	 specification.  */
      if (*fmt != '%')
	{
	  out_char (*fmt++);
	  continue;
	}

      /* "%%" means a single '%' character.  */
      if (fmt[1] == '%')
	{
	  out_char (*++fmt);
	  ++fmt;
	  continue;
	}

      /* Defaults for formatting.  */
      print_curr_symbol = 1;		/* Print the currency symbol.  */
      left_prec = -1;			/* No left precision specified.  */
      right_prec = -1;			/* No right precision specified.  */
      group = 1;			/* Print digits grouped.  */
      pad = ' ';			/* Fill character is <SP>.  */
      is_long_double = 0;		/* Double argument by default.  */
      p_sign_posn = -1;			/* This indicates whether the */
      n_sign_posn = -1;			/* '(' flag is given.  */
      width = -1;			/* No width specified so far.  */
      left = 0;				/* Right justified by default.  */

      /* Parse group characters.  */
      while (1)
	{
	  switch (*++fmt)
	    {
	    case '=':			/* Set fill character.  */
	      pad = *++fmt;
	      continue;
	    case '^':			/* Don't group digits.  */
	      group = 0;
	      continue;
	    case '+':			/* Use +/- for sign of number.  */
	      if (n_sign_posn != -1)
		{
		  errno = EINVAL;
		  va_end (ap);
		  return -1;
		}
	      if (*_NL_CURRENT (LC_MONETARY, P_SIGN_POSN) == '\0')
		p_sign_posn = 1;
	      else
		p_sign_posn = *_NL_CURRENT (LC_MONETARY, P_SIGN_POSN);
	      if (*_NL_CURRENT (LC_MONETARY, N_SIGN_POSN) == '\0')
		n_sign_posn = 1;
	      else
		n_sign_posn = *_NL_CURRENT (LC_MONETARY, N_SIGN_POSN);
	      continue;
	    case '(':			/* Use ( ) for negative sign.  */
	      if (n_sign_posn != -1)
		{
		  errno = EINVAL;
		  va_end (ap);
		  return -1;
		}
	      n_sign_posn = 5;	/* This is a else unused value.  */
	      continue;
	    case '!':			/* Don't print the currency symbol.  */
	      print_curr_symbol = 0;
	      continue;
	    case '-':			/* Print left justified.  */
	      left = 1;
	      continue;
	    default:
	      /* Will stop the loop.  */;
	    }
	  break;
	}

      if (isdigit (*fmt))
	{
	  /* Parse field width.  */
	  width = to_digit (*fmt);

	  while (isdigit (*++fmt))
	    {
	      width *= 10;
	      width += to_digit (*fmt);
	    }

	  /* If we don't have enough room for the demanded width we
	     can stop now and return an error.  */
	  if (dest + width >= s + maxsize)
	    {
	      errno = E2BIG;
	      va_end (ap);
	      return -1;
	    }
	}

      /* Recognize left precision.  */
      if (*fmt == '#')
	{
	  if (!isdigit (*++fmt))
	    {
	      errno = EINVAL;
	      va_end (ap);
	      return -1;
	    }
	  left_prec = to_digit (*fmt);

	  while (isdigit (*++fmt))
	    {
	      left_prec *= 10;
	      left_prec += to_digit (*fmt);
	    }
	}

      /* Recognize right precision.  */
      if (*fmt == '.')
	{
	  if (!isdigit (*++fmt))
	    {
	      errno = EINVAL;
	      va_end (ap);
	      return -1;
	    }
	  right_prec = to_digit (*fmt);

	  while (isdigit (*++fmt))
	    {
	      right_prec *= 10;
	      right_prec += to_digit (*fmt);
	    }
	}

      /* Handle modifier.  This is an extension.  */
      if (*fmt == 'L')
	{
	  ++fmt;
	  is_long_double = 1;
	}
      
      /* Handle format specifier.  */
      switch (*fmt++)
	{
	case 'i':		/* Use international currency symbol.  */
	  currency_symbol = _NL_CURRENT (LC_MONETARY, INT_CURR_SYMBOL);
	  if (right_prec == -1)
	    if (*_NL_CURRENT (LC_MONETARY, INT_FRAC_DIGITS) == '\177')
	      right_prec = 2;
	    else
	      right_prec = *_NL_CURRENT (LC_MONETARY, INT_FRAC_DIGITS);
	  break;
	case 'n':		/* Use national currency symbol.  */
	  currency_symbol = _NL_CURRENT (LC_MONETARY, CURRENCY_SYMBOL);
	  if (right_prec == -1)
	    if (*_NL_CURRENT (LC_MONETARY, FRAC_DIGITS) == '\177')
	      right_prec = 2;
	    else
	      right_prec = *_NL_CURRENT (LC_MONETARY, FRAC_DIGITS);
	  break;
	default:		/* Any unrecognized format is an error.  */
	  errno = EINVAL;
	  va_end (ap);
	  return -1;
	}

      /* If we have to print the digits grouped determine how many
	 extra characters this means.  */
      if (group && left_prec != -1)
	left_prec += __guess_grouping (left_prec,
				       _NL_CURRENT (LC_MONETARY, MON_GROUPING),
				       *_NL_CURRENT (LC_MONETARY,
						     MON_THOUSANDS_SEP));
      
      /* Now it's time to get the value.  */
      if (is_long_double == 1)
	{
	  fpnum.ldbl = va_arg (ap, long double);
	  is_negative = fpnum.ldbl < 0;
	  if (is_negative)
	    fpnum.ldbl = -fpnum.ldbl;
	}
      else
	{
	  fpnum.dbl = va_arg (ap, double);
	  is_negative = fpnum.dbl < 0;
	  if (is_negative)
	    fpnum.dbl = -fpnum.dbl;
	}

      /* We now know the sign of the value and can determine the format.  */
      if (is_negative)
	{
	  sign_char = *_NL_CURRENT (LC_MONETARY, NEGATIVE_SIGN);
	  /* If the locale does not specify a character for the
	     negative sign we use a '-'.  */
	  if (sign_char == '\0')
	    sign_char = '-';
	  cs_precedes = *_NL_CURRENT (LC_MONETARY, N_CS_PRECEDES);
	  sep_by_space = *_NL_CURRENT (LC_MONETARY, N_SEP_BY_SPACE);
	  /* If the '(' flag is not given use the sign position from
	     the current locale.  */
	  if (n_sign_posn == -1)
	    sign_posn = *_NL_CURRENT (LC_MONETARY, N_SIGN_POSN);
	  else
	    /* This means use parentheses.  */
	    sign_posn = 0;
	}
      else
	{
	  sign_char = *_NL_CURRENT (LC_MONETARY, POSITIVE_SIGN);
	  /* If the locale does not specify a character for the
	     positive sign we use a <SP>.  */
	  if (sign_char == '\0')
	    sign_char = ' ';
	  cs_precedes = *_NL_CURRENT (LC_MONETARY, P_CS_PRECEDES);
	  sep_by_space = *_NL_CURRENT (LC_MONETARY, P_SEP_BY_SPACE);
	  if (n_sign_posn == -1)
	    sign_posn = *_NL_CURRENT (LC_MONETARY, P_SIGN_POSN);
	  else
	    /* Here we don't set SIGN_POSN to 0 because we don'want to
	       print <SP> instead of the braces and this is what the
	       value 5 means.  */
	    sign_posn = 5;
	}

      /* Set default values for unspecified information.  */
      if (cs_precedes != 0)
	cs_precedes = 1;
      if (sep_by_space == 127)
	sep_by_space = 0;
      if (left_prec == -1)
	left_prec = 0;
	

      /* Perhaps we'll someday make these things configurable so
	 better start using symbolic names now.  */
#define left_paren '('
#define right_paren ')'

      startp = dest;		/* Remember start so we can compute lenght.  */
      
      if (sign_posn == 0)
	out_char (left_paren);
      if (sign_posn == 5)	/* This is for positive number and ( flag.  */
	out_char (' ');

      if (cs_precedes)
	{
	  if (sign_posn != 0 && sign_posn != 2 && sign_posn != 4
	      && sign_posn != 5)
	    {
	      out_char (sign_char);
	      if (sep_by_space == 2)
		out_char (' ');
	    }
	  
	  if (print_curr_symbol)
	    {
	      out_string (currency_symbol);

	      if (sign_posn == 4)
		{
		  if (sep_by_space == 2)
		    out_char (' ');
		  out_char (sign_char);
		}
	      else
		if (sep_by_space == 1)
		  out_char (' ');
	    }
	}
      else
	if (sign_posn != 0 && sign_posn != 2 && sign_posn != 3
	    && sign_posn != 4 && sign_posn != 5)
	  out_char (sign_char);

      /* Print the number.  */
#ifdef USE_IN_LIBIO
      _IO_init ((_IO_FILE *) &f, 0);
      _IO_JUMPS ((_IO_FILE *) &f) = &_IO_str_jumps;
      _IO_str_init_static ((_IO_FILE *) &f, dest, (s + maxsize) - dest, dest);
#else
      memset((PTR) &f, 0, sizeof(f));
      f.__magic = _IOMAGIC;
      f.__mode.__write = 1;
      /* The buffer size is one less than MAXLEN
	 so we have space for the null terminator.  */
      f.__bufp = f.__buffer = (char *) dest;
      f.__bufsize = (s + maxsize) - dest;
      f.__put_limit = f.__buffer + f.__bufsize;
      f.__get_limit = f.__buffer;
      /* After the buffer is full (MAXLEN characters have been written),
	 any more characters written will go to the bit bucket.  */
      f.__room_funcs = __default_room_functions;
      f.__io_funcs.__write = NULL;
      f.__seen = 1;
#endif
      /* We clear the last available byte so we can find out whether
	 the numeric representation is too long.  */
      s[maxsize - 1] = '\0';

      info.prec = right_prec;
      info.width = left_prec + (right_prec ? (right_prec + 1) : 0);
      info.spec = 'f';
      info.is_long_double = is_long_double;
      info.is_short = 0;
      info.is_long = 0;
      info.alt = 0;
      info.space = 0;
      info.left = left;
      info.showsign = 0;
      info.group = group;
      info.pad = pad;
      info.extra = 1;		/* This means use values from LC_MONETARY.  */

      ptr = &fpnum;
      done = __printf_fp ((FILE *) &f, &info, &ptr);
      if (done < 0)
	{
	  va_end (ap);
	  return -1;
	}

      if (s[maxsize - 1] != '\0')
	return -1;

      dest += done;
      
      if (!cs_precedes)
	{
	  if (sign_posn == 3)
	    {
	      if (sep_by_space == 1)
		out_char (' ');
	      out_char (sign_char);
	    }

	  if (print_curr_symbol)
	    {
	      if (sign_posn == 3 && sep_by_space == 2)
		out_char (' ');
	      out_string (currency_symbol);
	    }
	}
      else
	if (sign_posn == 2)
	  {
	    if (sep_by_space == 2)
	      out_char (' ');
	    out_char (sign_char);
	  }
      
      if (sign_posn == 0)
	out_char (right_paren);
      if (sign_posn == 5)
	out_char (' ');		/* This is for positive number and ( flag.  */

      /* Now test whether the output width is filled.  */
      if (dest - startp < width)
	if (left)
	  /* We simply have to fill using spaces.  */
	  do
	    out_char (' ');
	  while (dest - startp < width);
	else
	  {
	    int dist = width - (dest - startp);
	    char *cp;
	    for (cp = dest - 1; cp >= startp; --cp)
	      cp[dist] = cp[0];

	    dest += dist;

	    do
	      startp[--dist] = ' ';
	    while (dist > 0);
	  }
    }

  /* Terminate the string.  */
  out_char ('\0');
  
  va_end (ap);

  return dest - s - 1;
}