Added Util_asprintf,Util_asnprintf,Util_snprintf,Util_vsnprintf.

asprintf is like sprintf, but the first arg is a char ** and should basically be
the address of a null pointer.  The routine allocates enough space and passes back
the new buffer pointer.

asnprintf is as above, but the buffer need not be null.  The thirs argument is the
size of the current buffer, and if the string would be larger than that, the current
buffer is freed and a new buffer big enough is allocated.

snprintf and vsnprintf are pretty standard, except we don't have them on all platforms
so I hunted down a file on the internet, written by Patrick Powel (papowell@astart.com),
to give us a portable version of the functionality.  It may not be entirely up to
scratch with floating point - I've not tested it too thouroughly yet.

This should enable us to make the web-server stuff a bit more secure against buffer-overruns.

Tom


git-svn-id: http://svn.cactuscode.org/flesh/trunk@2210 17b73243-c579-4c4c-a9d2-2d5706c11dac

1 files changed, 850 insertions, 0 deletions

diff --git a/src/util/snprintf.c b/src/util/snprintf.c
new file mode 100644
index 00000000..99d4b64a
--- /dev/null
+++ b/src/util/snprintf.c
@@ -0,0 +1,850 @@
+/*
+ * Copyright Patrick Powell 1995
+ * This code is based on code written by Patrick Powell (papowell@astart.com)
+ * It may be used for any purpose as long as this notice remains intact
+ * on all source code distributions
+ */
+
+/**************************************************************
+ * Original:
+ * Patrick Powell Tue Apr 11 09:48:21 PDT 1995
+ * A bombproof version of doprnt (dopr) included.
+ * Sigh.  This sort of thing is always nasty do deal with.  Note that
+ * the version here does not include floating point...
+ *
+ * snprintf() is used instead of sprintf() as it does limit checks
+ * for string length.  This covers a nasty loophole.
+ *
+ * The other functions are there to prevent NULL pointers from
+ * causing nast effects.
+ *
+ * More Recently:
+ *  Brandon Long <blong@fiction.net> 9/15/96 for mutt 0.43
+ *  This was ugly.  It is still ugly.  I opted out of floating point
+ *  numbers, but the formatter understands just about everything
+ *  from the normal C string format, at least as far as I can tell from
+ *  the Solaris 2.5 printf(3S) man page.
+ *
+ *  Brandon Long <blong@fiction.net> 10/22/97 for mutt 0.87.1
+ *    Ok, added some minimal floating point support, which means this
+ *    probably requires libm on most operating systems.  Don't yet
+ *    support the exponent (e,E) and sigfig (g,G).  Also, fmtint()
+ *    was pretty badly broken, it just wasn't being exercised in ways
+ *    which showed it, so that's been fixed.  Also, formated the code
+ *    to mutt conventions, and removed dead code left over from the
+ *    original.  Also, there is now a builtin-test, just compile with:
+ *           gcc -DTEST_SNPRINTF -o snprintf snprintf.c -lm
+ *    and run snprintf for results.
+ * 
+ *  Thomas Roessler <roessler@guug.de> 01/27/98 for mutt 0.89i
+ *    The PGP code was using unsigned hexadecimal formats. 
+ *    Unfortunately, unsigned formats simply didn't work.
+ *
+ *  Michael Elkins <me@cs.hmc.edu> 03/05/98 for mutt 0.90.8
+ *    The original code assumed that both snprintf() and vsnprintf() were
+ *    missing.  Some systems only have snprintf() but not vsnprintf(), so
+ *    the code is now broken down under HAVE_SNPRINTF and HAVE_VSNPRINTF.
+ *
+ *  Andrew Tridgell (tridge@samba.org) Oct 1998
+ *    fixed handling of %.0f
+ *    added test for HAVE_LONG_DOUBLE
+ *
+ *  Russ Allbery <rra@stanford.edu> 2000-08-26
+ *    fixed return value to comply with C99
+ *    fixed handling of snprintf(NULL, ...)
+ *
+ *  Tom Goodale <goodale@aei-potsdam.mpg.de> 2001-05-24
+ *    Put into CCTK
+ *
+ **************************************************************/
+
+
+#if 0 /* CCTK: Don't need this for CCTK */
+#include "config.h"
+#endif
+
+/* CCTK: Since we rely on ISO C, can just define this. */ 
+#define HAVE_STDARG_H 1
+
+/* CCTK: Rename functions for CCTK. */
+#define snprintf Util_snprintf
+#define vsnprintf Util_vsnprintf
+
+#if !defined(HAVE_SNPRINTF) || !defined(HAVE_VSNPRINTF) 
+
+
+#include <string.h>
+#include <ctype.h>
+#include <sys/types.h>
+
+/* Define this as a fall through, HAVE_STDARG_H is probably already set */
+
+#define HAVE_VARARGS_H
+
+
+/* varargs declarations: */
+
+#if defined(HAVE_STDARG_H)
+# include <stdarg.h>
+# define HAVE_STDARGS    /* let's hope that works everywhere (mj) */
+# define VA_LOCAL_DECL   va_list ap
+# define VA_START(f)     va_start(ap, f)
+# define VA_SHIFT(v,t)  ;   /* no-op for ANSI */
+# define VA_END          va_end(ap)
+#else
+# if defined(HAVE_VARARGS_H)
+#  include <varargs.h>
+#  undef HAVE_STDARGS
+#  define VA_LOCAL_DECL   va_list ap
+#  define VA_START(f)     va_start(ap)      /* f is ignored! */
+#  define VA_SHIFT(v,t) v = va_arg(ap,t)
+#  define VA_END        va_end(ap)
+# else
+/*XX ** NO VARARGS ** XX*/
+# endif
+#endif
+
+#ifdef HAVE_LONG_DOUBLE
+#define LDOUBLE long double
+#else
+#define LDOUBLE double
+#endif
+
+int snprintf (char *str, size_t count, const char *fmt, ...);
+int vsnprintf (char *str, size_t count, const char *fmt, va_list arg);
+
+static int dopr (char *buffer, size_t maxlen, const char *format, 
+                 va_list args);
+static int fmtstr (char *buffer, size_t *currlen, size_t maxlen,
+		   char *value, int flags, int min, int max);
+static int fmtint (char *buffer, size_t *currlen, size_t maxlen,
+		   long value, int base, int min, int max, int flags);
+static int fmtfp (char *buffer, size_t *currlen, size_t maxlen,
+		  LDOUBLE fvalue, int min, int max, int flags);
+static int dopr_outch (char *buffer, size_t *currlen, size_t maxlen, char c );
+
+/*
+ * dopr(): poor man's version of doprintf
+ */
+
+/* format read states */
+#define DP_S_DEFAULT 0
+#define DP_S_FLAGS   1
+#define DP_S_MIN     2
+#define DP_S_DOT     3
+#define DP_S_MAX     4
+#define DP_S_MOD     5
+#define DP_S_CONV    6
+#define DP_S_DONE    7
+
+/* format flags - Bits */
+#define DP_F_MINUS 	(1 << 0)
+#define DP_F_PLUS  	(1 << 1)
+#define DP_F_SPACE 	(1 << 2)
+#define DP_F_NUM   	(1 << 3)
+#define DP_F_ZERO  	(1 << 4)
+#define DP_F_UP    	(1 << 5)
+#define DP_F_UNSIGNED 	(1 << 6)
+
+/* Conversion Flags */
+#define DP_C_SHORT   1
+#define DP_C_LONG    2
+#define DP_C_LDOUBLE 3
+
+#define char_to_int(p) (p - '0')
+#define MAX(p,q) ((p >= q) ? p : q)
+#define MIN(p,q) ((p <= q) ? p : q)
+
+static int dopr (char *buffer, size_t maxlen, const char *format, va_list args)
+{
+  char ch;
+  long value;
+  LDOUBLE fvalue;
+  char *strvalue;
+  int min;
+  int max;
+  int state;
+  int flags;
+  int cflags;
+  int total;
+  size_t currlen;
+  
+  state = DP_S_DEFAULT;
+  currlen = flags = cflags = min = 0;
+  max = -1;
+  ch = *format++;
+  total = 0;
+
+  while (state != DP_S_DONE)
+  {
+    if (ch == '\0')
+      state = DP_S_DONE;
+
+    switch(state) 
+    {
+    case DP_S_DEFAULT:
+      if (ch == '%') 
+	state = DP_S_FLAGS;
+      else 
+	total += dopr_outch (buffer, &currlen, maxlen, ch);
+      ch = *format++;
+      break;
+    case DP_S_FLAGS:
+      switch (ch) 
+      {
+      case '-':
+	flags |= DP_F_MINUS;
+        ch = *format++;
+	break;
+      case '+':
+	flags |= DP_F_PLUS;
+        ch = *format++;
+	break;
+      case ' ':
+	flags |= DP_F_SPACE;
+        ch = *format++;
+	break;
+      case '#':
+	flags |= DP_F_NUM;
+        ch = *format++;
+	break;
+      case '0':
+	flags |= DP_F_ZERO;
+        ch = *format++;
+	break;
+      default:
+	state = DP_S_MIN;
+	break;
+      }
+      break;
+    case DP_S_MIN:
+      if (isdigit(ch)) 
+      {
+	min = 10*min + char_to_int (ch);
+	ch = *format++;
+      } 
+      else if (ch == '*') 
+      {
+	min = va_arg (args, int);
+	ch = *format++;
+	state = DP_S_DOT;
+      } 
+      else 
+	state = DP_S_DOT;
+      break;
+    case DP_S_DOT:
+      if (ch == '.') 
+      {
+	state = DP_S_MAX;
+	ch = *format++;
+      } 
+      else 
+	state = DP_S_MOD;
+      break;
+    case DP_S_MAX:
+      if (isdigit(ch)) 
+      {
+	if (max < 0)
+	  max = 0;
+	max = 10*max + char_to_int (ch);
+	ch = *format++;
+      } 
+      else if (ch == '*') 
+      {
+	max = va_arg (args, int);
+	ch = *format++;
+	state = DP_S_MOD;
+      } 
+      else 
+	state = DP_S_MOD;
+      break;
+    case DP_S_MOD:
+      /* Currently, we don't support Long Long, bummer */
+      switch (ch) 
+      {
+      case 'h':
+	cflags = DP_C_SHORT;
+	ch = *format++;
+	break;
+      case 'l':
+	cflags = DP_C_LONG;
+	ch = *format++;
+	break;
+      case 'L':
+	cflags = DP_C_LDOUBLE;
+	ch = *format++;
+	break;
+      default:
+	break;
+      }
+      state = DP_S_CONV;
+      break;
+    case DP_S_CONV:
+      switch (ch) 
+      {
+      case 'd':
+      case 'i':
+	if (cflags == DP_C_SHORT) 
+	  value = va_arg (args, short int);
+	else if (cflags == DP_C_LONG)
+	  value = va_arg (args, long int);
+	else
+	  value = va_arg (args, int);
+	total += fmtint (buffer, &currlen, maxlen, value, 10, min, max, flags);
+	break;
+      case 'o':
+	flags |= DP_F_UNSIGNED;
+	if (cflags == DP_C_SHORT)
+	  value = va_arg (args, unsigned short int);
+	else if (cflags == DP_C_LONG)
+	  value = va_arg (args, unsigned long int);
+	else
+	  value = va_arg (args, unsigned int);
+	total += fmtint (buffer, &currlen, maxlen, value, 8, min, max, flags);
+	break;
+      case 'u':
+	flags |= DP_F_UNSIGNED;
+	if (cflags == DP_C_SHORT)
+	  value = va_arg (args, unsigned short int);
+	else if (cflags == DP_C_LONG)
+	  value = va_arg (args, unsigned long int);
+	else
+	  value = va_arg (args, unsigned int);
+	total += fmtint (buffer, &currlen, maxlen, value, 10, min, max, flags);
+	break;
+      case 'X':
+	flags |= DP_F_UP;
+      case 'x':
+	flags |= DP_F_UNSIGNED;
+	if (cflags == DP_C_SHORT)
+	  value = va_arg (args, unsigned short int);
+	else if (cflags == DP_C_LONG)
+	  value = va_arg (args, unsigned long int);
+	else
+	  value = va_arg (args, unsigned int);
+	total += fmtint (buffer, &currlen, maxlen, value, 16, min, max, flags);
+	break;
+      case 'f':
+	if (cflags == DP_C_LDOUBLE)
+	  fvalue = va_arg (args, LDOUBLE);
+	else
+	  fvalue = va_arg (args, double);
+	/* um, floating point? */
+	total += fmtfp (buffer, &currlen, maxlen, fvalue, min, max, flags);
+	break;
+      case 'E':
+	flags |= DP_F_UP;
+      case 'e':
+	if (cflags == DP_C_LDOUBLE)
+	  fvalue = va_arg (args, LDOUBLE);
+	else
+	  fvalue = va_arg (args, double);
+	break;
+      case 'G':
+	flags |= DP_F_UP;
+      case 'g':
+	if (cflags == DP_C_LDOUBLE)
+	  fvalue = va_arg (args, LDOUBLE);
+	else
+	  fvalue = va_arg (args, double);
+	break;
+      case 'c':
+	total += dopr_outch (buffer, &currlen, maxlen, va_arg (args, int));
+	break;
+      case 's':
+	strvalue = va_arg (args, char *);
+	total += fmtstr (buffer, &currlen, maxlen, strvalue, flags, min, max);
+	break;
+      case 'p':
+	strvalue = va_arg (args, void *);
+	total += fmtint (buffer, &currlen, maxlen, (long) strvalue, 16, min,
+                         max, flags);
+	break;
+      case 'n':
+	if (cflags == DP_C_SHORT) 
+	{
+	  short int *num;
+	  num = va_arg (args, short int *);
+	  *num = currlen;
+        } 
+	else if (cflags == DP_C_LONG) 
+	{
+	  long int *num;
+	  num = va_arg (args, long int *);
+	  *num = currlen;
+        } 
+	else 
+	{
+	  int *num;
+	  num = va_arg (args, int *);
+	  *num = currlen;
+        }
+	break;
+      case '%':
+	total += dopr_outch (buffer, &currlen, maxlen, ch);
+	break;
+      case 'w':
+	/* not supported yet, treat as next char */
+	ch = *format++;
+	break;
+      default:
+	/* Unknown, skip */
+	break;
+      }
+      ch = *format++;
+      state = DP_S_DEFAULT;
+      flags = cflags = min = 0;
+      max = -1;
+      break;
+    case DP_S_DONE:
+      break;
+    default:
+      /* hmm? */
+      break; /* some picky compilers need this */
+    }
+  }
+  if (buffer != NULL)
+  {
+    if (currlen < maxlen - 1) 
+      buffer[currlen] = '\0';
+    else 
+      buffer[maxlen - 1] = '\0';
+  }
+  return total;
+}
+
+static int fmtstr (char *buffer, size_t *currlen, size_t maxlen,
+                   char *value, int flags, int min, int max)
+{
+  int padlen, strln;     /* amount to pad */
+  int cnt = 0;
+  int total = 0;
+  
+  if (value == 0)
+  {
+    value = "<NULL>";
+  }
+
+  for (strln = 0; value[strln]; ++strln); /* strlen */
+  if (max >= 0 && max < strln)
+    strln = max;
+  padlen = min - strln;
+  if (padlen < 0) 
+    padlen = 0;
+  if (flags & DP_F_MINUS) 
+    padlen = -padlen; /* Left Justify */
+
+  while (padlen > 0)
+  {
+    total += dopr_outch (buffer, currlen, maxlen, ' ');
+    --padlen;
+  }
+  while (*value && ((max < 0) || (cnt < max)))
+  {
+    total += dopr_outch (buffer, currlen, maxlen, *value++);
+    ++cnt;
+  }
+  while (padlen < 0)
+  {
+    total += dopr_outch (buffer, currlen, maxlen, ' ');
+    ++padlen;
+  }
+  return total;
+}
+
+/* Have to handle DP_F_NUM (ie 0x and 0 alternates) */
+
+static int fmtint (char *buffer, size_t *currlen, size_t maxlen,
+		   long value, int base, int min, int max, int flags)
+{
+  int signvalue = 0;
+  unsigned long uvalue;
+  char convert[20];
+  int place = 0;
+  int spadlen = 0; /* amount to space pad */
+  int zpadlen = 0; /* amount to zero pad */
+  int caps = 0;
+  int total = 0;
+  
+  if (max < 0)
+    max = 0;
+
+  uvalue = value;
+
+  if(!(flags & DP_F_UNSIGNED))
+  {
+    if( value < 0 ) {
+      signvalue = '-';
+      uvalue = -value;
+    }
+    else
+      if (flags & DP_F_PLUS)  /* Do a sign (+/i) */
+	signvalue = '+';
+    else
+      if (flags & DP_F_SPACE)
+	signvalue = ' ';
+  }
+  
+  if (flags & DP_F_UP) caps = 1; /* Should characters be upper case? */
+
+  do {
+    convert[place++] =
+      (caps? "0123456789ABCDEF":"0123456789abcdef")
+      [uvalue % (unsigned)base  ];
+    uvalue = (uvalue / (unsigned)base );
+  } while(uvalue && (place < 20));
+  if (place == 20) place--;
+  convert[place] = 0;
+
+  zpadlen = max - place;
+  spadlen = min - MAX (max, place) - (signvalue ? 1 : 0);
+  if (zpadlen < 0) zpadlen = 0;
+  if (spadlen < 0) spadlen = 0;
+  if (flags & DP_F_ZERO)
+  {
+    zpadlen = MAX(zpadlen, spadlen);
+    spadlen = 0;
+  }
+  if (flags & DP_F_MINUS) 
+    spadlen = -spadlen; /* Left Justifty */
+
+#ifdef DEBUG_SNPRINTF
+  dprint (1, (debugfile, "zpad: %d, spad: %d, min: %d, max: %d, place: %d\n",
+      zpadlen, spadlen, min, max, place));
+#endif
+
+  /* Spaces */
+  while (spadlen > 0) 
+  {
+    total += dopr_outch (buffer, currlen, maxlen, ' ');
+    --spadlen;
+  }
+
+  /* Sign */
+  if (signvalue) 
+    total += dopr_outch (buffer, currlen, maxlen, signvalue);
+
+  /* Zeros */
+  if (zpadlen > 0) 
+  {
+    while (zpadlen > 0)
+    {
+      total += dopr_outch (buffer, currlen, maxlen, '0');
+      --zpadlen;
+    }
+  }
+
+  /* Digits */
+  while (place > 0) 
+    total += dopr_outch (buffer, currlen, maxlen, convert[--place]);
+  
+  /* Left Justified spaces */
+  while (spadlen < 0) {
+    total += dopr_outch (buffer, currlen, maxlen, ' ');
+    ++spadlen;
+  }
+
+  return total;
+}
+
+static LDOUBLE abs_val (LDOUBLE value)
+{
+  LDOUBLE result = value;
+
+  if (value < 0)
+    result = -value;
+
+  return result;
+}
+
+static LDOUBLE pow10 (int exp)
+{
+  LDOUBLE result = 1;
+
+  while (exp)
+  {
+    result *= 10;
+    exp--;
+  }
+  
+  return result;
+}
+
+static long round (LDOUBLE value)
+{
+  long intpart;
+
+  intpart = value;
+  value = value - intpart;
+  if (value >= 0.5)
+    intpart++;
+
+  return intpart;
+}
+
+static int fmtfp (char *buffer, size_t *currlen, size_t maxlen,
+		  LDOUBLE fvalue, int min, int max, int flags)
+{
+  int signvalue = 0;
+  LDOUBLE ufvalue;
+  char iconvert[20];
+  char fconvert[20];
+  int iplace = 0;
+  int fplace = 0;
+  int padlen = 0; /* amount to pad */
+  int zpadlen = 0; 
+  int caps = 0;
+  int total = 0;
+  long intpart;
+  long fracpart;
+  
+  /* 
+   * AIX manpage says the default is 0, but Solaris says the default
+   * is 6, and sprintf on AIX defaults to 6
+   */
+  if (max < 0)
+    max = 6;
+
+  ufvalue = abs_val (fvalue);
+
+  if (fvalue < 0)
+    signvalue = '-';
+  else
+    if (flags & DP_F_PLUS)  /* Do a sign (+/i) */
+      signvalue = '+';
+    else
+      if (flags & DP_F_SPACE)
+	signvalue = ' ';
+
+#if 0
+  if (flags & DP_F_UP) caps = 1; /* Should characters be upper case? */
+#endif
+
+  intpart = ufvalue;
+
+  /* 
+   * Sorry, we only support 9 digits past the decimal because of our 
+   * conversion method
+   */
+  if (max > 9)
+    max = 9;
+
+  /* We "cheat" by converting the fractional part to integer by
+   * multiplying by a factor of 10
+   */
+  fracpart = round ((pow10 (max)) * (ufvalue - intpart));
+
+  if (fracpart >= pow10 (max))
+  {
+    intpart++;
+    fracpart -= pow10 (max);
+  }
+
+#ifdef DEBUG_SNPRINTF
+  dprint (1, (debugfile, "fmtfp: %f =? %d.%d\n", fvalue, intpart, fracpart));
+#endif
+
+  /* Convert integer part */
+  do {
+    iconvert[iplace++] =
+      (caps? "0123456789ABCDEF":"0123456789abcdef")[intpart % 10];
+    intpart = (intpart / 10);
+  } while(intpart && (iplace < 20));
+  if (iplace == 20) iplace--;
+  iconvert[iplace] = 0;
+
+  /* Convert fractional part */
+  do {
+    fconvert[fplace++] =
+      (caps? "0123456789ABCDEF":"0123456789abcdef")[fracpart % 10];
+    fracpart = (fracpart / 10);
+  } while(fracpart && (fplace < 20));
+  if (fplace == 20) fplace--;
+  fconvert[fplace] = 0;
+
+  /* -1 for decimal point, another -1 if we are printing a sign */
+  padlen = min - iplace - max - 1 - ((signvalue) ? 1 : 0); 
+  zpadlen = max - fplace;
+  if (zpadlen < 0)
+    zpadlen = 0;
+  if (padlen < 0) 
+    padlen = 0;
+  if (flags & DP_F_MINUS) 
+    padlen = -padlen; /* Left Justifty */
+
+  if ((flags & DP_F_ZERO) && (padlen > 0)) 
+  {
+    if (signvalue) 
+    {
+      total += dopr_outch (buffer, currlen, maxlen, signvalue);
+      --padlen;
+      signvalue = 0;
+    }
+    while (padlen > 0)
+    {
+      total += dopr_outch (buffer, currlen, maxlen, '0');
+      --padlen;
+    }
+  }
+  while (padlen > 0)
+  {
+    total += dopr_outch (buffer, currlen, maxlen, ' ');
+    --padlen;
+  }
+  if (signvalue) 
+    total += dopr_outch (buffer, currlen, maxlen, signvalue);
+
+  while (iplace > 0) 
+    total += dopr_outch (buffer, currlen, maxlen, iconvert[--iplace]);
+
+  /*
+   * Decimal point.  This should probably use locale to find the correct
+   * char to print out.
+   */
+  if (max > 0)
+  {
+    total += dopr_outch (buffer, currlen, maxlen, '.');
+
+    while (fplace > 0) 
+      total += dopr_outch (buffer, currlen, maxlen, fconvert[--fplace]);
+  }
+
+  while (zpadlen > 0)
+  {
+    total += dopr_outch (buffer, currlen, maxlen, '0');
+    --zpadlen;
+  }
+
+  while (padlen < 0) 
+  {
+    total += dopr_outch (buffer, currlen, maxlen, ' ');
+    ++padlen;
+  }
+
+  return total;
+}
+
+static int dopr_outch (char *buffer, size_t *currlen, size_t maxlen, char c)
+{
+  if (*currlen + 1 < maxlen)
+    buffer[(*currlen)++] = c;
+  return 1;
+}
+
+#ifndef HAVE_VSNPRINTF
+int vsnprintf (char *str, size_t count, const char *fmt, va_list args)
+{
+  if (str != NULL)
+    str[0] = 0;
+  return dopr(str, count, fmt, args);
+}
+#endif /* !HAVE_VSNPRINTF */
+
+#ifndef HAVE_SNPRINTF
+/* VARARGS3 */
+#ifdef HAVE_STDARGS
+int snprintf (char *str,size_t count,const char *fmt,...)
+#else
+int snprintf (va_alist) va_dcl
+#endif
+{
+#ifndef HAVE_STDARGS
+  char *str;
+  size_t count;
+  char *fmt;
+#endif
+  VA_LOCAL_DECL;
+  int total;
+    
+  VA_START (fmt);
+  VA_SHIFT (str, char *);
+  VA_SHIFT (count, size_t );
+  VA_SHIFT (fmt, char *);
+  total = vsnprintf(str, count, fmt, ap);
+  VA_END;
+  return total;
+}
+#endif /* !HAVE_SNPRINTF */
+
+#ifdef TEST_SNPRINTF
+#ifndef LONG_STRING
+#define LONG_STRING 1024
+#endif
+
+#include <stdio.h>
+
+int main (void)
+{
+  char buf1[LONG_STRING];
+  char buf2[LONG_STRING];
+  char *fp_fmt[] = {
+    "%-1.5f",
+    "%1.5f",
+    "%123.9f",
+    "%10.5f",
+    "% 10.5f",
+    "%+22.9f",
+    "%+4.9f",
+    "%01.3f",
+    "%4f",
+    "%3.1f",
+    "%3.2f",
+    "%.0f",
+    "%.1f",
+    NULL
+  };
+  double fp_nums[] = { -1.5, 134.21, 91340.2, 341.1234, 0203.9, 0.96, 0.996, 
+    0.9996, 1.996, 4.136, 0};
+  char *int_fmt[] = {
+    "%-1.5d",
+    "%1.5d",
+    "%123.9d",
+    "%5.5d",
+    "%10.5d",
+    "% 10.5d",
+    "%+22.33d",
+    "%01.3d",
+    "%4d",
+    NULL
+  };
+  long int_nums[] = { -1, 134, 91340, 341, 0203, 0};
+  int x, y;
+  int fail = 0;
+  int num = 0;
+
+  printf ("Testing snprintf format codes against system sprintf...\n");
+
+  for (x = 0; fp_fmt[x] != NULL ; x++)
+    for (y = 0; fp_nums[y] != 0 ; y++)
+    {
+      snprintf (buf1, sizeof (buf1), fp_fmt[x], fp_nums[y]);
+      sprintf (buf2, fp_fmt[x], fp_nums[y]);
+      if (strcmp (buf1, buf2))
+      {
+	printf("snprintf doesn't match Format: %s\n\tsnprintf = %s\n\tsprintf  = %s\n", 
+	    fp_fmt[x], buf1, buf2);
+	fail++;
+      }
+      num++;
+    }
+
+  for (x = 0; int_fmt[x] != NULL ; x++)
+    for (y = 0; int_nums[y] != 0 ; y++)
+    {
+      snprintf (buf1, sizeof (buf1), int_fmt[x], int_nums[y]);
+      sprintf (buf2, int_fmt[x], int_nums[y]);
+      if (strcmp (buf1, buf2))
+      {
+	printf("snprintf doesn't match Format: %s\n\tsnprintf = %s\n\tsprintf  = %s\n", 
+	    int_fmt[x], buf1, buf2);
+	fail++;
+      }
+      num++;
+    }
+  printf ("%d tests failed out of %d.\n", fail, num);
+
+  return 0;
+}
+#endif /* SNPRINTF_TEST */
+
+#endif /* !HAVE_SNPRINTF */