snprintf_2.2/snprintf.c

changeset 35
5a71d53d0228
child 100
8ae0f0aa5a16
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/snprintf_2.2/snprintf.c	Sat Jan 19 19:14:36 2002 +0100
@@ -0,0 +1,1032 @@
+#include <stdarg.h>
+#define NEED_ASPRINTF
+#define NEED_VASPRINTF
+/*
+ * snprintf.c - a portable implementation of snprintf
+ *
+ * AUTHOR
+ *   Mark Martinec <mark.martinec@ijs.si>, April 1999.
+ *
+ *   Copyright 1999, Mark Martinec. All rights reserved.
+ *
+ * TERMS AND CONDITIONS
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the "Frontier Artistic License" which comes
+ *   with this Kit.
+ *
+ *   This program 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 Frontier Artistic License for more details.
+ *
+ *   You should have received a copy of the Frontier Artistic License
+ *   with this Kit in the file named LICENSE.txt .
+ *   If not, I'll be glad to provide one.
+ *
+ * FEATURES
+ * - careful adherence to specs regarding flags, field width and precision;
+ * - good performance for large string handling (large format, large
+ *   argument or large paddings). Performance is similar to system's sprintf
+ *   and in several cases significantly better (make sure you compile with
+ *   optimizations turned on, tell the compiler the code is strict ANSI
+ *   if necessary to give it more freedom for optimizations);
+ * - return value semantics per ISO/IEC 9899:1999 ("ISO C99");
+ * - written in standard ISO/ANSI C - requires an ANSI C compiler.
+ *
+ * SUPPORTED CONVERSION SPECIFIERS AND DATA TYPES
+ *
+ * This snprintf only supports the following conversion specifiers:
+ * s, c, d, u, o, x, X, p  (and synonyms: i, D, U, O - see below)
+ * with flags: '-', '+', ' ', '0' and '#'.
+ * An asterisk is supported for field width as well as precision.
+ *
+ * Length modifiers 'h' (short int), 'l' (long int),
+ * and 'll' (long long int) are supported.
+ * NOTE:
+ *   If macro SNPRINTF_LONGLONG_SUPPORT is not defined (default) the
+ *   length modifier 'll' is recognized but treated the same as 'l',
+ *   which may cause argument value truncation! Defining
+ *   SNPRINTF_LONGLONG_SUPPORT requires that your system's sprintf also
+ *   handles length modifier 'll'.  long long int is a language extension
+ *   which may not be portable.
+ *
+ * Conversion of numeric data (conversion specifiers d, u, o, x, X, p)
+ * with length modifiers (none or h, l, ll) is left to the system routine
+ * sprintf, but all handling of flags, field width and precision as well as
+ * c and s conversions is done very carefully by this portable routine.
+ * If a string precision (truncation) is specified (e.g. %.8s) it is
+ * guaranteed the string beyond the specified precision will not be referenced.
+ *
+ * Length modifiers h, l and ll are ignored for c and s conversions (data
+ * types wint_t and wchar_t are not supported).
+ *
+ * The following common synonyms for conversion characters are supported:
+ *   - i is a synonym for d
+ *   - D is a synonym for ld, explicit length modifiers are ignored
+ *   - U is a synonym for lu, explicit length modifiers are ignored
+ *   - O is a synonym for lo, explicit length modifiers are ignored
+ * The D, O and U conversion characters are nonstandard, they are supported
+ * for backward compatibility only, and should not be used for new code.
+ *
+ * The following is specifically NOT supported:
+ *   - flag ' (thousands' grouping character) is recognized but ignored
+ *   - numeric conversion specifiers: f, e, E, g, G and synonym F,
+ *     as well as the new a and A conversion specifiers
+ *   - length modifier 'L' (long double) and 'q' (quad - use 'll' instead)
+ *   - wide character/string conversions: lc, ls, and nonstandard
+ *     synonyms C and S
+ *   - writeback of converted string length: conversion character n
+ *   - the n$ specification for direct reference to n-th argument
+ *   - locales
+ *
+ * It is permitted for str_m to be zero, and it is permitted to specify NULL
+ * pointer for resulting string argument if str_m is zero (as per ISO C99).
+ *
+ * The return value is the number of characters which would be generated
+ * for the given input, excluding the trailing null. If this value
+ * is greater or equal to str_m, not all characters from the result
+ * have been stored in str, output bytes beyond the (str_m-1) -th character
+ * are discarded. If str_m is greater than zero it is guaranteed
+ * the resulting string will be null-terminated.
+ *
+ * NOTE that this matches the ISO C99, OpenBSD, and GNU C library 2.1,
+ * but is different from some older and vendor implementations,
+ * and is also different from XPG, XSH5, SUSv2 specifications.
+ * For historical discussion on changes in the semantics and standards
+ * of snprintf see printf(3) man page in the Linux programmers manual.
+ *
+ * Routines asprintf and vasprintf return a pointer (in the ptr argument)
+ * to a buffer sufficiently large to hold the resulting string. This pointer
+ * should be passed to free(3) to release the allocated storage when it is
+ * no longer needed. If sufficient space cannot be allocated, these functions
+ * will return -1 and set ptr to be a NULL pointer. These two routines are a
+ * GNU C library extensions (glibc).
+ *
+ * Routines asnprintf and vasnprintf are similar to asprintf and vasprintf,
+ * yet, like snprintf and vsnprintf counterparts, will write at most str_m-1
+ * characters into the allocated output string, the last character in the
+ * allocated buffer then gets the terminating null. If the formatted string
+ * length (the return value) is greater than or equal to the str_m argument,
+ * the resulting string was truncated and some of the formatted characters
+ * were discarded. These routines present a handy way to limit the amount
+ * of allocated memory to some sane value.
+ *
+ * AVAILABILITY
+ *   http://www.ijs.si/software/snprintf/
+ *
+ * REVISION HISTORY
+ * 1999-04	V0.9  Mark Martinec
+ *		- initial version, some modifications after comparing printf
+ *		  man pages for Digital Unix 4.0, Solaris 2.6 and HPUX 10,
+ *		  and checking how Perl handles sprintf (differently!);
+ * 1999-04-09	V1.0  Mark Martinec <mark.martinec@ijs.si>
+ *		- added main test program, fixed remaining inconsistencies,
+ *		  added optional (long long int) support;
+ * 1999-04-12	V1.1  Mark Martinec <mark.martinec@ijs.si>
+ *		- support the 'p' conversion (pointer to void);
+ *		- if a string precision is specified
+ *		  make sure the string beyond the specified precision
+ *		  will not be referenced (e.g. by strlen);
+ * 1999-04-13	V1.2  Mark Martinec <mark.martinec@ijs.si>
+ *		- support synonyms %D=%ld, %U=%lu, %O=%lo;
+ *		- speed up the case of long format string with few conversions;
+ * 1999-06-30	V1.3  Mark Martinec <mark.martinec@ijs.si>
+ *		- fixed runaway loop (eventually crashing when str_l wraps
+ *		  beyond 2^31) while copying format string without
+ *		  conversion specifiers to a buffer that is too short
+ *		  (thanks to Edwin Young <edwiny@autonomy.com> for
+ *		  spotting the problem);
+ *		- added macros PORTABLE_SNPRINTF_VERSION_(MAJOR|MINOR)
+ *		  to snprintf.h
+ * 2000-02-14	V2.0 (never released) Mark Martinec <mark.martinec@ijs.si>
+ *		- relaxed license terms: The Artistic License now applies.
+ *		  You may still apply the GNU GENERAL PUBLIC LICENSE
+ *		  as was distributed with previous versions, if you prefer;
+ *		- changed REVISION HISTORY dates to use ISO 8601 date format;
+ *		- added vsnprintf (patch also independently proposed by
+ *		  Caolan McNamara 2000-05-04, and Keith M Willenson 2000-06-01)
+ * 2000-06-27	V2.1  Mark Martinec <mark.martinec@ijs.si>
+ *		- removed POSIX check for str_m<1; value 0 for str_m is
+ *		  allowed by ISO C99 (and GNU C library 2.1) - (pointed out
+ *		  on 2000-05-04 by Caolan McNamara, caolan@ csn dot ul dot ie).
+ *		  Besides relaxed license this change in standards adherence
+ *		  is the main reason to bump up the major version number;
+ *		- added nonstandard routines asnprintf, vasnprintf, asprintf,
+ *		  vasprintf that dynamically allocate storage for the
+ *		  resulting string; these routines are not compiled by default,
+ *		  see comments where NEED_V?ASN?PRINTF macros are defined;
+ *		- autoconf contributed by Caolan McNamara
+ * 2000-10-06	V2.2  Mark Martinec <mark.martinec@ijs.si>
+ *		- BUG FIX: the %c conversion used a temporary variable
+ *		  that was no longer in scope when referenced,
+ *		  possibly causing incorrect resulting character;
+ *		- BUG FIX: make precision and minimal field width unsigned
+ *		  to handle huge values (2^31 <= n < 2^32) correctly;
+ *		  also be more careful in the use of signed/unsigned/size_t
+ *		  internal variables - probably more careful than many
+ *		  vendor implementations, but there may still be a case
+ *		  where huge values of str_m, precision or minimal field
+ *		  could cause incorrect behaviour;
+ *		- use separate variables for signed/unsigned arguments,
+ *		  and for short/int, long, and long long argument lengths
+ *		  to avoid possible incompatibilities on certain
+ *		  computer architectures. Also use separate variable
+ *		  arg_sign to hold sign of a numeric argument,
+ *		  to make code more transparent;
+ *		- some fiddling with zero padding and "0x" to make it
+ *		  Linux compatible;
+ *		- systematically use macros fast_memcpy and fast_memset
+ *		  instead of case-by-case hand optimization; determine some
+ *		  breakeven string lengths for different architectures;
+ *		- terminology change: 'format' -> 'conversion specifier',
+ *		  'C9x' -> 'ISO/IEC 9899:1999 ("ISO C99")',
+ *		  'alternative form' -> 'alternate form',
+ *		  'data type modifier' -> 'length modifier';
+ *		- several comments rephrased and new ones added;
+ *		- make compiler not complain about 'credits' defined but
+ *		  not used;
+ */
+
+
+/* Define HAVE_SNPRINTF if your system already has snprintf and vsnprintf.
+ *
+ * If HAVE_SNPRINTF is defined this module will not produce code for
+ * snprintf and vsnprintf, unless PREFER_PORTABLE_SNPRINTF is defined as well,
+ * causing this portable version of snprintf to be called portable_snprintf
+ * (and portable_vsnprintf).
+ */
+/* #define HAVE_SNPRINTF */
+
+/* Define PREFER_PORTABLE_SNPRINTF if your system does have snprintf and
+ * vsnprintf but you would prefer to use the portable routine(s) instead.
+ * In this case the portable routine is declared as portable_snprintf
+ * (and portable_vsnprintf) and a macro 'snprintf' (and 'vsnprintf')
+ * is defined to expand to 'portable_v?snprintf' - see file snprintf.h .
+ * Defining this macro is only useful if HAVE_SNPRINTF is also defined,
+ * but does does no harm if defined nevertheless.
+ */
+/* #define PREFER_PORTABLE_SNPRINTF */
+
+/* Define SNPRINTF_LONGLONG_SUPPORT if you want to support
+ * data type (long long int) and length modifier 'll' (e.g. %lld).
+ * If undefined, 'll' is recognized but treated as a single 'l'.
+ *
+ * If the system's sprintf does not handle 'll'
+ * the SNPRINTF_LONGLONG_SUPPORT must not be defined!
+ *
+ * This is off by default as (long long int) is a language extension.
+ */
+/* #define SNPRINTF_LONGLONG_SUPPORT */
+
+/* Define NEED_SNPRINTF_ONLY if you only need snprintf, and not vsnprintf.
+ * If NEED_SNPRINTF_ONLY is defined, the snprintf will be defined directly,
+ * otherwise both snprintf and vsnprintf routines will be defined
+ * and snprintf will be a simple wrapper around vsnprintf, at the expense
+ * of an extra procedure call.
+ */
+/* #define NEED_SNPRINTF_ONLY */
+
+/* Define NEED_V?ASN?PRINTF macros if you need library extension
+ * routines asprintf, vasprintf, asnprintf, vasnprintf respectively,
+ * and your system library does not provide them. They are all small
+ * wrapper routines around portable_vsnprintf. Defining any of the four
+ * NEED_V?ASN?PRINTF macros automatically turns off NEED_SNPRINTF_ONLY
+ * and turns on PREFER_PORTABLE_SNPRINTF.
+ *
+ * Watch for name conflicts with the system library if these routines
+ * are already present there.
+ *
+ * NOTE: vasprintf and vasnprintf routines need va_copy() from stdarg.h, as
+ * specified by C99, to be able to traverse the same list of arguments twice.
+ * I don't know of any other standard and portable way of achieving the same.
+ * With some versions of gcc you may use __va_copy(). You might even get away
+ * with "ap2 = ap", in this case you must not call va_end(ap2) !
+ *   #define va_copy(ap2,ap) ap2 = ap
+ */
+#ifndef va_copy
+#define va_copy(ap2,ap) ap2 = ap 
+#endif
+
+/* #define NEED_ASPRINTF   */
+/* #define NEED_ASNPRINTF  */
+/* #define NEED_VASPRINTF  */
+/* #define NEED_VASNPRINTF */
+
+
+/* Define the following macros if desired:
+ *   SOLARIS_COMPATIBLE, SOLARIS_BUG_COMPATIBLE,
+ *   HPUX_COMPATIBLE, HPUX_BUG_COMPATIBLE, LINUX_COMPATIBLE,
+ *   DIGITAL_UNIX_COMPATIBLE, DIGITAL_UNIX_BUG_COMPATIBLE,
+ *   PERL_COMPATIBLE, PERL_BUG_COMPATIBLE,
+ *
+ * - For portable applications it is best not to rely on peculiarities
+ *   of a given implementation so it may be best not to define any
+ *   of the macros that select compatibility and to avoid features
+ *   that vary among the systems.
+ *
+ * - Selecting compatibility with more than one operating system
+ *   is not strictly forbidden but is not recommended.
+ *
+ * - 'x'_BUG_COMPATIBLE implies 'x'_COMPATIBLE .
+ *
+ * - 'x'_COMPATIBLE refers to (and enables) a behaviour that is
+ *   documented in a sprintf man page on a given operating system
+ *   and actually adhered to by the system's sprintf (but not on
+ *   most other operating systems). It may also refer to and enable
+ *   a behaviour that is declared 'undefined' or 'implementation specific'
+ *   in the man page but a given implementation behaves predictably
+ *   in a certain way.
+ *
+ * - 'x'_BUG_COMPATIBLE refers to (and enables) a behaviour of system's sprintf
+ *   that contradicts the sprintf man page on the same operating system.
+ *
+ * - I do not claim that the 'x'_COMPATIBLE and 'x'_BUG_COMPATIBLE
+ *   conditionals take into account all idiosyncrasies of a particular
+ *   implementation, there may be other incompatibilities.
+ */
+
+
+
+/* ============================================= */
+/* NO USER SERVICABLE PARTS FOLLOWING THIS POINT */
+/* ============================================= */
+
+#define PORTABLE_SNPRINTF_VERSION_MAJOR 2
+#define PORTABLE_SNPRINTF_VERSION_MINOR 2
+
+#if defined(NEED_ASPRINTF) || defined(NEED_ASNPRINTF) || defined(NEED_VASPRINTF) || defined(NEED_VASNPRINTF)
+# if defined(NEED_SNPRINTF_ONLY)
+# undef NEED_SNPRINTF_ONLY
+# endif
+# if !defined(PREFER_PORTABLE_SNPRINTF)
+# define PREFER_PORTABLE_SNPRINTF
+# endif
+#endif
+
+#if defined(SOLARIS_BUG_COMPATIBLE) && !defined(SOLARIS_COMPATIBLE)
+#define SOLARIS_COMPATIBLE
+#endif
+
+#if defined(HPUX_BUG_COMPATIBLE) && !defined(HPUX_COMPATIBLE)
+#define HPUX_COMPATIBLE
+#endif
+
+#if defined(DIGITAL_UNIX_BUG_COMPATIBLE) && !defined(DIGITAL_UNIX_COMPATIBLE)
+#define DIGITAL_UNIX_COMPATIBLE
+#endif
+
+#if defined(PERL_BUG_COMPATIBLE) && !defined(PERL_COMPATIBLE)
+#define PERL_COMPATIBLE
+#endif
+
+#if defined(LINUX_BUG_COMPATIBLE) && !defined(LINUX_COMPATIBLE)
+#define LINUX_COMPATIBLE
+#endif
+
+#include <sys/types.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <assert.h>
+#include <errno.h>
+
+#ifdef isdigit
+#undef isdigit
+#endif
+#define isdigit(c) ((c) >= '0' && (c) <= '9')
+
+/* For copying strings longer or equal to 'breakeven_point'
+ * it is more efficient to call memcpy() than to do it inline.
+ * The value depends mostly on the processor architecture,
+ * but also on the compiler and its optimization capabilities.
+ * The value is not critical, some small value greater than zero
+ * will be just fine if you don't care to squeeze every drop
+ * of performance out of the code.
+ *
+ * Small values favor memcpy, large values favor inline code.
+ */
+#if defined(__alpha__) || defined(__alpha)
+#  define breakeven_point   2	/* AXP (DEC Alpha)     - gcc or cc or egcs */
+#endif
+#if defined(__i386__)  || defined(__i386)
+#  define breakeven_point  12	/* Intel Pentium/Linux - gcc 2.96 */
+#endif
+#if defined(__hppa)
+#  define breakeven_point  10	/* HP-PA               - gcc */
+#endif
+#if defined(__sparc__) || defined(__sparc)
+#  define breakeven_point  33	/* Sun Sparc 5         - gcc 2.8.1 */
+#endif
+
+/* some other values of possible interest: */
+/* #define breakeven_point  8 */  /* VAX 4000          - vaxc */
+/* #define breakeven_point 19 */  /* VAX 4000          - gcc 2.7.0 */
+
+#ifndef breakeven_point
+#  define breakeven_point   6	/* some reasonable one-size-fits-all value */
+#endif
+
+#define fast_memcpy(d,s,n) \
+  { register size_t nn = (size_t)(n); \
+    if (nn >= breakeven_point) memcpy((d), (s), nn); \
+    else if (nn > 0) { /* proc call overhead is worth only for large strings*/\
+      register char *dd; register const char *ss; \
+      for (ss=(s), dd=(d); nn>0; nn--) *dd++ = *ss++; } }
+
+#define fast_memset(d,c,n) \
+  { register size_t nn = (size_t)(n); \
+    if (nn >= breakeven_point) memset((d), (int)(c), nn); \
+    else if (nn > 0) { /* proc call overhead is worth only for large strings*/\
+      register char *dd; register const int cc=(int)(c); \
+      for (dd=(d); nn>0; nn--) *dd++ = cc; } }
+
+/* prototypes */
+
+#if defined(NEED_ASPRINTF)
+int asprintf   (char **ptr, const char *fmt, /*args*/ ...);
+#endif
+#if defined(NEED_VASPRINTF)
+int vasprintf  (char **ptr, const char *fmt, va_list ap);
+#endif
+#if defined(NEED_ASNPRINTF)
+int asnprintf  (char **ptr, size_t str_m, const char *fmt, /*args*/ ...);
+#endif
+#if defined(NEED_VASNPRINTF)
+int vasnprintf (char **ptr, size_t str_m, const char *fmt, va_list ap);
+#endif
+
+#if defined(HAVE_SNPRINTF)
+/* declare our portable snprintf  routine under name portable_snprintf  */
+/* declare our portable vsnprintf routine under name portable_vsnprintf */
+#else
+/* declare our portable routines under names snprintf and vsnprintf */
+#define portable_snprintf snprintf
+#if !defined(NEED_SNPRINTF_ONLY)
+#define portable_vsnprintf vsnprintf
+#endif
+#endif
+
+#if !defined(HAVE_SNPRINTF) || defined(PREFER_PORTABLE_SNPRINTF)
+int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...);
+#if !defined(NEED_SNPRINTF_ONLY)
+int portable_vsnprintf(char *str, size_t str_m, const char *fmt, va_list ap);
+#endif
+#endif
+
+/* declarations */
+
+static char credits[] = "\n\
+@(#)snprintf.c, v2.2: Mark Martinec, <mark.martinec@ijs.si>\n\
+@(#)snprintf.c, v2.2: Copyright 1999, Mark Martinec. Frontier Artistic License applies.\n\
+@(#)snprintf.c, v2.2: http://www.ijs.si/software/snprintf/\n";
+
+#if defined(NEED_ASPRINTF)
+int asprintf(char **ptr, const char *fmt, /*args*/ ...) {
+  va_list ap;
+  size_t str_m;
+  int str_l;
+
+  *ptr = NULL;
+  va_start(ap, fmt);                            /* measure the required size */
+  str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap);
+  va_end(ap);
+  assert(str_l >= 0);        /* possible integer overflow if str_m > INT_MAX */
+  *ptr = (char *) malloc(str_m = (size_t)str_l + 1);
+  if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
+  else {
+    int str_l2;
+    va_start(ap, fmt);
+    str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
+    va_end(ap);
+    assert(str_l2 == str_l);
+  }
+  return str_l;
+}
+#endif
+
+#if defined(NEED_VASPRINTF)
+int vasprintf(char **ptr, const char *fmt, va_list ap) {
+  size_t str_m;
+  int str_l;
+
+  *ptr = NULL;
+  { va_list ap2;
+    va_copy(ap2, ap);  /* don't consume the original ap, we'll need it again */
+    str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap2);/*get required size*/
+    va_end(ap2);
+  }
+  assert(str_l >= 0);        /* possible integer overflow if str_m > INT_MAX */
+  *ptr = (char *) malloc(str_m = (size_t)str_l + 1);
+  if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
+  else {
+    int str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
+    assert(str_l2 == str_l);
+  }
+  return str_l;
+}
+#endif
+
+#if defined(NEED_ASNPRINTF)
+int asnprintf (char **ptr, size_t str_m, const char *fmt, /*args*/ ...) {
+  va_list ap;
+  int str_l;
+
+  *ptr = NULL;
+  va_start(ap, fmt);                            /* measure the required size */
+  str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap);
+  va_end(ap);
+  assert(str_l >= 0);        /* possible integer overflow if str_m > INT_MAX */
+  if ((size_t)str_l + 1 < str_m) str_m = (size_t)str_l + 1;      /* truncate */
+  /* if str_m is 0, no buffer is allocated, just set *ptr to NULL */
+  if (str_m == 0) {  /* not interested in resulting string, just return size */
+  } else {
+    *ptr = (char *) malloc(str_m);
+    if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
+    else {
+      int str_l2;
+      va_start(ap, fmt);
+      str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
+      va_end(ap);
+      assert(str_l2 == str_l);
+    }
+  }
+  return str_l;
+}
+#endif
+
+#if defined(NEED_VASNPRINTF)
+int vasnprintf (char **ptr, size_t str_m, const char *fmt, va_list ap) {
+  int str_l;
+
+  *ptr = NULL;
+  { va_list ap2;
+    va_copy(ap2, ap);  /* don't consume the original ap, we'll need it again */
+    str_l = portable_vsnprintf(NULL, (size_t)0, fmt, ap2);/*get required size*/
+    va_end(ap2);
+  }
+  assert(str_l >= 0);        /* possible integer overflow if str_m > INT_MAX */
+  if ((size_t)str_l + 1 < str_m) str_m = (size_t)str_l + 1;      /* truncate */
+  /* if str_m is 0, no buffer is allocated, just set *ptr to NULL */
+  if (str_m == 0) {  /* not interested in resulting string, just return size */
+  } else {
+    *ptr = (char *) malloc(str_m);
+    if (*ptr == NULL) { errno = ENOMEM; str_l = -1; }
+    else {
+      int str_l2 = portable_vsnprintf(*ptr, str_m, fmt, ap);
+      assert(str_l2 == str_l);
+    }
+  }
+  return str_l;
+}
+#endif
+
+/*
+ * If the system does have snprintf and the portable routine is not
+ * specifically required, this module produces no code for snprintf/vsnprintf.
+ */
+#if !defined(HAVE_SNPRINTF) || defined(PREFER_PORTABLE_SNPRINTF)
+
+#if !defined(NEED_SNPRINTF_ONLY)
+int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...) {
+  va_list ap;
+  int str_l;
+
+  va_start(ap, fmt);
+  str_l = portable_vsnprintf(str, str_m, fmt, ap);
+  va_end(ap);
+  return str_l;
+}
+#endif
+
+#if defined(NEED_SNPRINTF_ONLY)
+int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...) {
+#else
+int portable_vsnprintf(char *str, size_t str_m, const char *fmt, va_list ap) {
+#endif
+
+#if defined(NEED_SNPRINTF_ONLY)
+  va_list ap;
+#endif
+  size_t str_l = 0;
+  const char *p = fmt;
+
+/* In contrast with POSIX, the ISO C99 now says
+ * that str can be NULL and str_m can be 0.
+ * This is more useful than the old:  if (str_m < 1) return -1; */
+
+#if defined(NEED_SNPRINTF_ONLY)
+  va_start(ap, fmt);
+#endif
+  if (!p) p = "";
+  while (*p) {
+    if (*p != '%') {
+   /* if (str_l < str_m) str[str_l++] = *p++;    -- this would be sufficient */
+   /* but the following code achieves better performance for cases
+    * where format string is long and contains few conversions */
+      const char *q = strchr(p+1,'%');
+      size_t n = !q ? strlen(p) : (q-p);
+      if (str_l < str_m) {
+        size_t avail = str_m-str_l;
+        fast_memcpy(str+str_l, p, (n>avail?avail:n));
+      }
+      p += n; str_l += n;
+    } else {
+      const char *starting_p;
+      size_t min_field_width = 0, precision = 0;
+      int zero_padding = 0, precision_specified = 0, justify_left = 0;
+      int alternate_form = 0, force_sign = 0;
+      int space_for_positive = 1; /* If both the ' ' and '+' flags appear,
+                                     the ' ' flag should be ignored. */
+      char length_modifier = '\0';            /* allowed values: \0, h, l, L */
+      char tmp[32];/* temporary buffer for simple numeric->string conversion */
+
+      const char *str_arg;      /* string address in case of string argument */
+      size_t str_arg_l;         /* natural field width of arg without padding
+                                   and sign */
+      unsigned char uchar_arg;
+        /* unsigned char argument value - only defined for c conversion.
+           N.B. standard explicitly states the char argument for
+           the c conversion is unsigned */
+
+      size_t number_of_zeros_to_pad = 0;
+        /* number of zeros to be inserted for numeric conversions
+           as required by the precision or minimal field width */
+
+      size_t zero_padding_insertion_ind = 0;
+        /* index into tmp where zero padding is to be inserted */
+
+      char fmt_spec = '\0';
+        /* current conversion specifier character */
+
+      str_arg = credits;/* just to make compiler happy (defined but not used)*/
+      str_arg = NULL;
+      starting_p = p; p++;  /* skip '%' */
+   /* parse flags */
+      while (*p == '0' || *p == '-' || *p == '+' ||
+             *p == ' ' || *p == '#' || *p == '\'') {
+        switch (*p) {
+        case '0': zero_padding = 1; break;
+        case '-': justify_left = 1; break;
+        case '+': force_sign = 1; space_for_positive = 0; break;
+        case ' ': force_sign = 1;
+     /* If both the ' ' and '+' flags appear, the ' ' flag should be ignored */
+#ifdef PERL_COMPATIBLE
+     /* ... but in Perl the last of ' ' and '+' applies */
+                  space_for_positive = 1;
+#endif
+                  break;
+        case '#': alternate_form = 1; break;
+        case '\'': break;
+        }
+        p++;
+      }
+   /* If the '0' and '-' flags both appear, the '0' flag should be ignored. */
+
+   /* parse field width */
+      if (*p == '*') {
+        int j;
+        p++; j = va_arg(ap, int);
+        if (j >= 0) min_field_width = j;
+        else { min_field_width = -j; justify_left = 1; }
+      } else if (isdigit((int)(*p))) {
+        /* size_t could be wider than unsigned int;
+           make sure we treat argument like common implementations do */
+        unsigned int uj = *p++ - '0';
+        while (isdigit((int)(*p))) uj = 10*uj + (unsigned int)(*p++ - '0');
+        min_field_width = uj;
+      }
+   /* parse precision */
+      if (*p == '.') {
+        p++; precision_specified = 1;
+        if (*p == '*') {
+          int j = va_arg(ap, int);
+          p++;
+          if (j >= 0) precision = j;
+          else {
+            precision_specified = 0; precision = 0;
+         /* NOTE:
+          *   Solaris 2.6 man page claims that in this case the precision
+          *   should be set to 0.  Digital Unix 4.0, HPUX 10 and BSD man page
+          *   claim that this case should be treated as unspecified precision,
+          *   which is what we do here.
+          */
+          }
+        } else if (isdigit((int)(*p))) {
+          /* size_t could be wider than unsigned int;
+             make sure we treat argument like common implementations do */
+          unsigned int uj = *p++ - '0';
+          while (isdigit((int)(*p))) uj = 10*uj + (unsigned int)(*p++ - '0');
+          precision = uj;
+        }
+      }
+   /* parse 'h', 'l' and 'll' length modifiers */
+      if (*p == 'h' || *p == 'l') {
+        length_modifier = *p; p++;
+        if (length_modifier == 'l' && *p == 'l') {   /* double l = long long */
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+          length_modifier = '2';                  /* double l encoded as '2' */
+#else
+          length_modifier = 'l';                 /* treat it as a single 'l' */
+#endif
+          p++;
+        }
+      }
+      fmt_spec = *p;
+   /* common synonyms: */
+      switch (fmt_spec) {
+      case 'i': fmt_spec = 'd'; break;
+      case 'D': fmt_spec = 'd'; length_modifier = 'l'; break;
+      case 'U': fmt_spec = 'u'; length_modifier = 'l'; break;
+      case 'O': fmt_spec = 'o'; length_modifier = 'l'; break;
+      default: break;
+      }
+   /* get parameter value, do initial processing */
+      switch (fmt_spec) {
+      case '%': /* % behaves similar to 's' regarding flags and field widths */
+      case 'c': /* c behaves similar to 's' regarding flags and field widths */
+      case 's':
+        length_modifier = '\0';          /* wint_t and wchar_t not supported */
+     /* the result of zero padding flag with non-numeric conversion specifier*/
+     /* is undefined. Solaris and HPUX 10 does zero padding in this case,    */
+     /* Digital Unix and Linux does not. */
+#if !defined(SOLARIS_COMPATIBLE) && !defined(HPUX_COMPATIBLE)
+        zero_padding = 0;    /* turn zero padding off for string conversions */
+#endif
+        str_arg_l = 1;
+        switch (fmt_spec) {
+        case '%':
+          str_arg = p; break;
+        case 'c': {
+          int j = va_arg(ap, int);
+          uchar_arg = (unsigned char) j;   /* standard demands unsigned char */
+          str_arg = (const char *) &uchar_arg;
+          break;
+        }
+        case 's':
+          str_arg = va_arg(ap, const char *);
+          if (!str_arg) str_arg_l = 0;
+       /* make sure not to address string beyond the specified precision !!! */
+          else if (!precision_specified) str_arg_l = strlen(str_arg);
+       /* truncate string if necessary as requested by precision */
+          else if (precision == 0) str_arg_l = 0;
+          else {
+       /* memchr on HP does not like n > 2^31  !!! */
+            const char *q = memchr(str_arg, '\0',
+                             precision <= 0x7fffffff ? precision : 0x7fffffff);
+            str_arg_l = !q ? precision : (q-str_arg);
+          }
+          break;
+        default: break;
+        }
+        break;
+      case 'd': case 'u': case 'o': case 'x': case 'X': case 'p': {
+        /* NOTE: the u, o, x, X and p conversion specifiers imply
+                 the value is unsigned;  d implies a signed value */
+
+        int arg_sign = 0;
+          /* 0 if numeric argument is zero (or if pointer is NULL for 'p'),
+            +1 if greater than zero (or nonzero for unsigned arguments),
+            -1 if negative (unsigned argument is never negative) */
+
+        int int_arg = 0;  unsigned int uint_arg = 0;
+          /* only defined for length modifier h, or for no length modifiers */
+
+        long int long_arg = 0;  unsigned long int ulong_arg = 0;
+          /* only defined for length modifier l */
+
+        void *ptr_arg = NULL;
+          /* pointer argument value -only defined for p conversion */
+
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+        long long int long_long_arg = 0;
+        unsigned long long int ulong_long_arg = 0;
+          /* only defined for length modifier ll */
+#endif
+        if (fmt_spec == 'p') {
+        /* HPUX 10: An l, h, ll or L before any other conversion character
+         *   (other than d, i, u, o, x, or X) is ignored.
+         * Digital Unix:
+         *   not specified, but seems to behave as HPUX does.
+         * Solaris: If an h, l, or L appears before any other conversion
+         *   specifier (other than d, i, u, o, x, or X), the behavior
+         *   is undefined. (Actually %hp converts only 16-bits of address
+         *   and %llp treats address as 64-bit data which is incompatible
+         *   with (void *) argument on a 32-bit system).
+         */
+#ifdef SOLARIS_COMPATIBLE
+#  ifdef SOLARIS_BUG_COMPATIBLE
+          /* keep length modifiers even if it represents 'll' */
+#  else
+          if (length_modifier == '2') length_modifier = '\0';
+#  endif
+#else
+          length_modifier = '\0';
+#endif
+          ptr_arg = va_arg(ap, void *);
+          if (ptr_arg != NULL) arg_sign = 1;
+        } else if (fmt_spec == 'd') {  /* signed */
+          switch (length_modifier) {
+          case '\0':
+          case 'h':
+         /* It is non-portable to specify a second argument of char or short
+          * to va_arg, because arguments seen by the called function
+          * are not char or short.  C converts char and short arguments
+          * to int before passing them to a function.
+          */
+            int_arg = va_arg(ap, int);
+            if      (int_arg > 0) arg_sign =  1;
+            else if (int_arg < 0) arg_sign = -1;
+            break;
+          case 'l':
+            long_arg = va_arg(ap, long int);
+            if      (long_arg > 0) arg_sign =  1;
+            else if (long_arg < 0) arg_sign = -1;
+            break;
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+          case '2':
+            long_long_arg = va_arg(ap, long long int);
+            if      (long_long_arg > 0) arg_sign =  1;
+            else if (long_long_arg < 0) arg_sign = -1;
+            break;
+#endif
+          }
+        } else {  /* unsigned */
+          switch (length_modifier) {
+          case '\0':
+          case 'h':
+            uint_arg = va_arg(ap, unsigned int);
+            if (uint_arg) arg_sign = 1;
+            break;
+          case 'l':
+            ulong_arg = va_arg(ap, unsigned long int);
+            if (ulong_arg) arg_sign = 1;
+            break;
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+          case '2':
+            ulong_long_arg = va_arg(ap, unsigned long long int);
+            if (ulong_long_arg) arg_sign = 1;
+            break;
+#endif
+          }
+        }
+        str_arg = tmp; str_arg_l = 0;
+     /* NOTE:
+      *   For d, i, u, o, x, and X conversions, if precision is specified,
+      *   the '0' flag should be ignored. This is so with Solaris 2.6,
+      *   Digital UNIX 4.0, HPUX 10, Linux, FreeBSD, NetBSD; but not with Perl.
+      */
+#ifndef PERL_COMPATIBLE
+        if (precision_specified) zero_padding = 0;
+#endif
+        if (fmt_spec == 'd') {
+          if (force_sign && arg_sign >= 0)
+            tmp[str_arg_l++] = space_for_positive ? ' ' : '+';
+         /* leave negative numbers for sprintf to handle,
+            to avoid handling tricky cases like (short int)(-32768) */
+#ifdef LINUX_COMPATIBLE
+        } else if (fmt_spec == 'p' && force_sign && arg_sign > 0) {
+          tmp[str_arg_l++] = space_for_positive ? ' ' : '+';
+#endif
+        } else if (alternate_form) {
+          if (arg_sign != 0 && (fmt_spec == 'x' || fmt_spec == 'X') )
+            { tmp[str_arg_l++] = '0'; tmp[str_arg_l++] = fmt_spec; }
+         /* alternate form should have no effect for p conversion, but ... */
+#ifdef HPUX_COMPATIBLE
+          else if (fmt_spec == 'p'
+         /* HPUX 10: for an alternate form of p conversion,
+          *          a nonzero result is prefixed by 0x. */
+#ifndef HPUX_BUG_COMPATIBLE
+         /* Actually it uses 0x prefix even for a zero value. */
+                   && arg_sign != 0
+#endif
+                  ) { tmp[str_arg_l++] = '0'; tmp[str_arg_l++] = 'x'; }
+#endif
+        }
+        zero_padding_insertion_ind = str_arg_l;
+        if (!precision_specified) precision = 1;   /* default precision is 1 */
+        if (precision == 0 && arg_sign == 0
+#if defined(HPUX_BUG_COMPATIBLE) || defined(LINUX_COMPATIBLE)
+            && fmt_spec != 'p'
+         /* HPUX 10 man page claims: With conversion character p the result of
+          * converting a zero value with a precision of zero is a null string.
+          * Actually HP returns all zeroes, and Linux returns "(nil)". */
+#endif
+        ) {
+         /* converted to null string */
+         /* When zero value is formatted with an explicit precision 0,
+            the resulting formatted string is empty (d, i, u, o, x, X, p).   */
+        } else {
+          char f[5]; int f_l = 0;
+          f[f_l++] = '%';    /* construct a simple format string for sprintf */
+          if (!length_modifier) { }
+          else if (length_modifier=='2') { f[f_l++] = 'l'; f[f_l++] = 'l'; }
+          else f[f_l++] = length_modifier;
+          f[f_l++] = fmt_spec; f[f_l++] = '\0';
+          if (fmt_spec == 'p') str_arg_l += sprintf(tmp+str_arg_l, f, ptr_arg);
+          else if (fmt_spec == 'd') {  /* signed */
+            switch (length_modifier) {
+            case '\0':
+            case 'h': str_arg_l+=sprintf(tmp+str_arg_l, f, int_arg);  break;
+            case 'l': str_arg_l+=sprintf(tmp+str_arg_l, f, long_arg); break;
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+            case '2': str_arg_l+=sprintf(tmp+str_arg_l,f,long_long_arg); break;
+#endif
+            }
+          } else {  /* unsigned */
+            switch (length_modifier) {
+            case '\0':
+            case 'h': str_arg_l+=sprintf(tmp+str_arg_l, f, uint_arg);  break;
+            case 'l': str_arg_l+=sprintf(tmp+str_arg_l, f, ulong_arg); break;
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+            case '2': str_arg_l+=sprintf(tmp+str_arg_l,f,ulong_long_arg);break;
+#endif
+            }
+          }
+         /* include the optional minus sign and possible "0x"
+            in the region before the zero padding insertion point */
+          if (zero_padding_insertion_ind < str_arg_l &&
+              tmp[zero_padding_insertion_ind] == '-') {
+            zero_padding_insertion_ind++;
+          }
+          if (zero_padding_insertion_ind+1 < str_arg_l &&
+              tmp[zero_padding_insertion_ind]   == '0' &&
+             (tmp[zero_padding_insertion_ind+1] == 'x' ||
+              tmp[zero_padding_insertion_ind+1] == 'X') ) {
+            zero_padding_insertion_ind += 2;
+          }
+        }
+        { size_t num_of_digits = str_arg_l - zero_padding_insertion_ind;
+          if (alternate_form && fmt_spec == 'o'
+#ifdef HPUX_COMPATIBLE                                  /* ("%#.o",0) -> ""  */
+              && (str_arg_l > 0)
+#endif
+#ifdef DIGITAL_UNIX_BUG_COMPATIBLE                      /* ("%#o",0) -> "00" */
+#else
+              /* unless zero is already the first character */
+              && !(zero_padding_insertion_ind < str_arg_l
+                   && tmp[zero_padding_insertion_ind] == '0')
+#endif
+          ) {        /* assure leading zero for alternate-form octal numbers */
+            if (!precision_specified || precision < num_of_digits+1) {
+             /* precision is increased to force the first character to be zero,
+                except if a zero value is formatted with an explicit precision
+                of zero */
+              precision = num_of_digits+1; precision_specified = 1;
+            }
+          }
+       /* zero padding to specified precision? */
+          if (num_of_digits < precision) 
+            number_of_zeros_to_pad = precision - num_of_digits;
+        }
+     /* zero padding to specified minimal field width? */
+        if (!justify_left && zero_padding) {
+          int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
+          if (n > 0) number_of_zeros_to_pad += n;
+        }
+        break;
+      }
+      default: /* unrecognized conversion specifier, keep format string as-is*/
+        zero_padding = 0;  /* turn zero padding off for non-numeric convers. */
+#ifndef DIGITAL_UNIX_COMPATIBLE
+        justify_left = 1; min_field_width = 0;                /* reset flags */
+#endif
+#if defined(PERL_COMPATIBLE) || defined(LINUX_COMPATIBLE)
+     /* keep the entire format string unchanged */
+        str_arg = starting_p; str_arg_l = p - starting_p;
+     /* well, not exactly so for Linux, which does something inbetween,
+      * and I don't feel an urge to imitate it: "%+++++hy" -> "%+y"  */
+#else
+     /* discard the unrecognized conversion, just keep *
+      * the unrecognized conversion character          */
+        str_arg = p; str_arg_l = 0;
+#endif
+        if (*p) str_arg_l++;  /* include invalid conversion specifier unchanged
+                                 if not at end-of-string */
+        break;
+      }
+      if (*p) p++;      /* step over the just processed conversion specifier */
+   /* insert padding to the left as requested by min_field_width;
+      this does not include the zero padding in case of numerical conversions*/
+      if (!justify_left) {                /* left padding with blank or zero */
+        int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
+        if (n > 0) {
+          if (str_l < str_m) {
+            ssize_t avail = str_m-str_l;
+            fast_memset(str+str_l, (zero_padding?'0':' '), (n>avail?avail:n));
+          }
+          str_l += n;
+        }
+      }
+   /* zero padding as requested by the precision or by the minimal field width
+    * for numeric conversions required? */
+      if (number_of_zeros_to_pad <= 0) {
+     /* will not copy first part of numeric right now, *
+      * force it to be copied later in its entirety    */
+        zero_padding_insertion_ind = 0;
+      } else {
+     /* insert first part of numerics (sign or '0x') before zero padding */
+        int n = zero_padding_insertion_ind;
+        if (n > 0) {
+          if (str_l < str_m) {
+            ssize_t avail = str_m-str_l;
+            fast_memcpy(str+str_l, str_arg, (n>avail?avail:n));
+          }
+          str_l += n;
+        }
+     /* insert zero padding as requested by the precision or min field width */
+        n = number_of_zeros_to_pad;
+        if (n > 0) {
+          if (str_l < str_m) {
+            ssize_t avail = str_m-str_l;
+            fast_memset(str+str_l, '0', (n>avail?avail:n));
+          }
+          str_l += n;
+        }
+      }
+   /* insert formatted string
+    * (or as-is conversion specifier for unknown conversions) */
+      { int n = str_arg_l - zero_padding_insertion_ind;
+        if (n > 0) {
+          if (str_l < str_m) {
+            ssize_t avail = str_m-str_l;
+            fast_memcpy(str+str_l, str_arg+zero_padding_insertion_ind,
+                        (n>avail?avail:n));
+          }
+          str_l += n;
+        }
+      }
+   /* insert right padding */
+      if (justify_left) {          /* right blank padding to the field width */
+        int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
+        if (n > 0) {
+          if (str_l < str_m) {
+            ssize_t avail = str_m-str_l;
+            fast_memset(str+str_l, ' ', (n>avail?avail:n));
+          }
+          str_l += n;
+        }
+      }
+    }
+  }
+#if defined(NEED_SNPRINTF_ONLY)
+  va_end(ap);
+#endif
+  if (str_m > 0) { /* make sure the string is null-terminated
+                      even at the expense of overwriting the last character
+                      (shouldn't happen, but just in case) */
+    str[str_l <= str_m-1 ? str_l : str_m-1] = '\0';
+  }
+  /* Return the number of characters formatted (excluding trailing null
+   * character), that is, the number of characters that would have been
+   * written to the buffer if it were large enough.
+   *
+   * The value of str_l should be returned, but str_l is of unsigned type
+   * size_t, and snprintf is int, possibly leading to an undetected
+   * integer overflow, resulting in a negative return value, which is illegal.
+   * Both XSH5 and ISO C99 (at least the draft) are silent on this issue.
+   * Should errno be set to EOVERFLOW and EOF returned in this case???
+   */
+  return (int) str_l;
+}
+#endif

mercurial