gnupg/util/vasprintf.c

/* Like vsprintf but provides a pointer to malloc'd storage, which must
   be freed by the caller.
   Copyright (C) 1994, 2002 Free Software Foundation, Inc.

This file is part of the libiberty library.
Libiberty 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.

Libiberty 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 libiberty; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>

#ifdef TEST
int global_total_width;
#endif

int
vasprintf (char **result, const char *format, va_list args)
{
  const char *p = format;
  /* Add one to make sure that it is never zero, which might cause malloc
     to return NULL.  */
  int total_width = strlen (format) + 1;
  va_list ap;

#ifdef va_copy
  va_copy (ap, args);
#else
#ifdef __va_copy
  __va_copy (ap, args);
#else
  memcpy (&ap, args, sizeof (va_list));
#endif /* __va_copy */
#endif /* va_copy */

  while (*p != '\0')
    {
      if (*p++ == '%')
	{
	  while (strchr ("-+ #0", *p))
	    ++p;
	  if (*p == '*')
	    {
	      ++p;
	      total_width += abs (va_arg (ap, int));
	    }
	  else
	    total_width += strtoul (p, (char**)&p, 10);
	  if (*p == '.')
	    {
	      ++p;
	      if (*p == '*')
		{
		  ++p;
		  total_width += abs (va_arg (ap, int));
		}
	      else
	      total_width += strtoul (p, (char**)&p, 10);
	    }
	  while (strchr ("hlL", *p))
	    ++p;
	  /* Should be big enough for any format specifier except %s
             and floats.  */
	  total_width += 30;
	  switch (*p)
	    {
	    case 'd':
	    case 'i':
	    case 'o':
	    case 'u':
	    case 'x':
	    case 'X':
	    case 'c':
	      (void) va_arg (ap, int);
	      break;
	    case 'f':
	    case 'e':
	    case 'E':
	    case 'g':
	    case 'G':
	      (void) va_arg (ap, double);
	      /* Since an ieee double can have an exponent of 307, we'll
		 make the buffer wide enough to cover the gross case. */
	      total_width += 307;
	      break;
	    case 's':
              {
                char *tmp = va_arg (ap, char *);
                if (tmp)
                  total_width += strlen (tmp);
                else /* in case the vsprintf does prints a text */
                  total_width += 25; /* e.g. "(null pointer reference)" */
              }
	      break;
	    case 'p':
	    case 'n':
	      (void) va_arg (ap, char *);
	      break;
	    }
	}
    }
#ifdef TEST
  global_total_width = total_width;
#endif
  *result = malloc (total_width);
  if (*result != NULL)
    return vsprintf (*result, format, args);
  else
    return 0;
}


int
asprintf (char **buf, const char *fmt, ...)
{
  int status;
  va_list ap;

  va_start (ap, fmt);
  status = vasprintf (buf, fmt, ap);
  va_end (ap);
  return status;
}


#ifdef TEST
void
checkit (const char* format, ...)
{
  va_list args;
  char *result;

  va_start (args, format);
  vasprintf (&result, format, args);
  if (strlen (result) < global_total_width)
    printf ("PASS: ");
  else
    printf ("FAIL: ");
  printf ("%d %s\n", global_total_width, result);
}

int
main (void)
{
  checkit ("%d", 0x12345678);
  checkit ("%200d", 5);
  checkit ("%.300d", 6);
  checkit ("%100.150d", 7);
  checkit ("%s", "jjjjjjjjjiiiiiiiiiiiiiiioooooooooooooooooppppppppppppaa\n\
777777777777777777333333333333366666666666622222222222777777777777733333");
  checkit ("%f%s%d%s", 1.0, "foo", 77, "asdjffffffffffffffiiiiiiiiiiixxxxx");
}
#endif /* TEST */