/*
 * 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 as per ISO C9X;
 * - written in standard ISO/ANSI C - requires an ANSI C compiler.
 *
 * SUPPORTED FORMATS AND DATA TYPES
 *
 * This snprintf only supports format specifiers:
 * s, c, d, o, u, 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.
 *
 * Data type 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
 *   data type modifier 'll' is recognized but treated the same as 'l',
sn *   which may cause argument value truncation! Defining
 *   SNPRINTF_LONGLONG_SUPPORT requires that your system's sprintf also
 *   handles data type modifier 'll'. long long int is a language
 *   extension which may not be portable.
 *
 * Conversion of numeric data (formats d, o, u, x, X, p) with data type
 * 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 formats 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.
 *
 * Data type modifiers h, l and ll are ignored for c and s formats (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 data type modifiers are ignored
 *   - U is a synonym for lu, explicit data type modifiers are ignored
 *   - O is a synonym for lo, explicit data type modifiers are ignored
 *
 * The following is specifically not supported:
 *   - flag ' (thousands' grouping character) is recognized but ignored
 *   - numeric formats: f, e, E, g, G and synonym F
 *   - data type modifier 'L' (long double) and 'q' (quad - use 'll' instead)
 *   - wide character/string formats: C, lc, S, ls
 *   - writeback of converted string length: conversion character n
 *   - the n$ specification for direct reference to n-th argument
 *   - locales
 *
 * It is permitted for size to be zero, and it is permitted to specify NULL
 * pointer for resulting string argument if str_m is zero (as per ISO C9X).
 *
 * 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. If str_m is greater than zero it is
 * guaranteed the resulting string will be null-terminated.
 *
 * NOTE that this matches the ISO C9X and GNU C library 2.1,
 * but is different from some older implementations!
 *
 * 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' format (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 C9X (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
 */


/* 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 fli_portable_snprintf
 * (and fli_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 fli_portable_snprintf
 * (and fli_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 data type 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 since (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 fli_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 C9X, 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 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,
 *   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.
 */

/* added by Lgb, the LyX Project */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

/* ============================================= */
/* NO USER SERVICABLE PARTS FOLLOWING THIS POINT */
/* ============================================= */

#define PORTABLE_SNPRINTF_VERSION_MAJOR 2
#define PORTABLE_SNPRINTF_VERSION_MINOR 1

#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


#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' )

/* prototypes */

#if defined ( NEED_ASPRINTF )
int asprintf( char **,
              const char *,
              ... );
#endif
#if defined ( NEED_VASPRINTF )
int vasprintf( char **,
               const char *,
               va_list );
#endif
#if defined ( NEED_ASNPRINTF )
int asnprintf( char **,
               size_t,
               const char *,
               ... );
#endif
#if defined ( NEED_VASNPRINTF )
int vasnprintf( char **,
                size_t,
                const char *,
                va_list );
#endif

#ifndef va_copy
#define va_copy( ap2, ap )  ap2 = ap
#endif

#if 0
#if defined ( HAVE_SNPRINTF )
/* declare our portable snprintf  routine under name fli_portable_snprintf  */
/* declare our portable vsnprintf routine under name fli_portable_vsnprintf */
#else
/* declare our portable routines under names snprintf and vsnprintf */
#define fli_portable_snprintf snprintf
#if !defined ( NEED_SNPRINTF_ONLY )
#define fli_portable_vsnprintf vsnprintf
#endif
#endif
#endif /* 0 */

#if ! defined ( HAVE_SNPRINTF ) || defined ( PREFER_PORTABLE_SNPRINTF )
int fli_portable_snprintf( char *,
                           size_t,
                           const char *,
                          ... );
#if ! defined ( NEED_SNPRINTF_ONLY )
int fli_portable_vsnprintf( char *,
                            size_t,
                            const char *,
                            va_list );
#endif
#endif


/***************************************
 ***************************************/

#if defined ( NEED_ASPRINTF )
int asprintf( char **ptr,
              const char *fmt,
              ... )
{
    va_list ap;
    size_t str_m;
    int str_l;

    *ptr = NULL;
    va_start( ap, fmt );                       /* measure the required size */
    str_l = fli_portable_vsnprintf( NULL, ( size_t ) 0, fmt, ap );
    va_end( ap );

    assert( str_l >= 0 );    /* possible integer overflow if str_m > INT_MAX */

    *ptr = fl_malloc( str_m = str_l + 1 );
    if ( *ptr == NULL )
    {
        errno = ENOMEM;
        str_l = -1;
    }
    else
    {
        int str_l2;

        va_start( ap, fmt );
        str_l2 = fli_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 */

        /* measure the required size: */

        str_l = fli_portable_vsnprintf( NULL, ( size_t ) 0, fmt, ap2 );
        va_end( ap2 );
    }

    assert( str_l >= 0 );     /* possible integer overflow if str_m > INT_MAX */

    *ptr = fl_malloc( str_m = str_l + 1 );

    if ( *ptr == NULL )
    {
        errno = ENOMEM;
        str_l = -1;
    }
    else
    {
        int str_l2 = fli_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,
           ... )
{
    va_list ap;
    int str_l;

    *ptr = NULL;
    va_start( ap, fmt );                        /* measure the required size */
    str_l = fli_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 = fl_malloc( str_m );
        if ( *ptr == NULL )
        {
            errno = ENOMEM;
            str_l = -1;
        }
        else
        {
            int str_l2;

            va_start( ap, fmt );
            str_l2 = fli_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 */

        /* measure the required size: */

        str_l = fli_portable_vsnprintf( NULL, ( size_t ) 0, fmt, ap2 );
        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 = fl_malloc( str_m );
        if ( *ptr == NULL )
        {
            errno = ENOMEM;
            str_l = -1;
        }
        else
        {
            int str_l2 = fli_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
fli_portable_snprintf( char       * str,
                       size_t       str_m,
                       const char * fmt,
                       ... )
{
    va_list ap;
    int str_l;

    va_start( ap, fmt );
    str_l = fli_portable_vsnprintf( str, str_m, fmt, ap );
    va_end( ap );
    return str_l;
}
#endif


/***************************************
 ***************************************/

#if defined ( NEED_SNPRINTF_ONLY )
int
fli_portable_snprintf( char       * str,
                       size_t       str_m,
                       const char * fmt,
                       ... )
{
#else
int
fli_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 to POSIX the ISO C9X now says that str can be NULL
       and str_m can be 0. This is more useful. */

    /*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, '%' );

             int n = ! q ? strlen( p ) : ( q - p );
             int avail = ( int ) ( str_m - str_l );

             if ( avail > 0 )
             {
                 int k;
                 char *r;
                 const char* p1;

                 for ( p1 = p, r = str + str_l, k = ( n > avail ? avail : n );
                       k > 0 ; k-- )
                     *r++ = *p1++;
             }
             p += n;
             str_l += n;
         }
         else
         {
             const char *starting_p;
             int min_field_width = 0,
                 precision = 0;
             int zero_padding = 0,
                 precision_specified = 0,
                 justify_left = 0;
             int alternative_form = 0,
                 force_sign = 0;
             int space_for_positive = 1; /* If both the ' ' and '+' flags
                                            appear, the ' ' flag should be
                                            ignored. */
             char data_type_modifier = '\0';/* allowed valued: \0, h, l, L, p */
             char tmp[ 32 ];                /* temporary buffer for simple
                                               numeric->string conversion */

             const char *str_arg = NULL;    /* string address in case of
                                               string arguments  */
             int str_arg_l;                 /* natural field width of arg
                                               without padding and sign */
             int j;
             long int long_arg;  /* long int argument value - always defined
                                    in case of numeric arguments, regardless
                                    of data type modifiers. In case of data
                                    type modifier 'll' the value is stored in
                                    long_long_arg and only the sign of long_arg
                                    is guaranteed to be correct */
             void *ptr_arg;      /* pointer argument value - only defined for
                                    p format   */
             int int_arg;        /* int argument value - only defined if no
                                    h or l modif.*/
#ifdef SNPRINTF_LONGLONG_SUPPORT
             long long int long_long_arg = 0; /* long long argument value - only
                                                 defined if ll modifier is
                                                 present */
#endif
             int number_of_zeros_to_pad = 0;
             int zero_padding_insertion_ind = 0;
             char fmt_spec = '\0';            /* current format specifier
                                                 character */

             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 '#':
                         alternative_form = 1;
                         break;

                     case '\'':
                         break;
                 }

                 p++;
             }

             /* If the '0' and '-' flags both appear, the '0' flag should
                be ignored. */

             /* parse field width */

             if ( *p == '*' )
             {
                 p++;
                 min_field_width = va_arg( ap, int );
                 if ( min_field_width < 0 )
                 {
                     min_field_width = -min_field_width;
                     justify_left = 1;
                 }
             }
             else if ( isdigit( ( unsigned char ) *p ) )
             {
                 min_field_width = *p++ - '0';
                 while (isdigit( ( unsigned char ) *p ) )
                     min_field_width = 10 * min_field_width + ( *p++ - '0' );
             }

             /* parse precision */

             if ( *p == '.' )
             {
                 p++;
                 precision_specified = 1;
                 if ( *p == '*' )
                 {
                     p++;
                     precision = va_arg( ap, int );
                     if ( precision < 0 )
                     {
                         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 and HPUX 10 man page claim that this
                          * case should be treated as unspecified precision,
                          * which is what we do here.
                          */
                     }
                 } else if ( isdigit( ( unsigned char ) *p ) )
                 {
                     precision = *p++ - '0';
                     while ( isdigit( ( unsigned char ) *p ) )
                         precision = 10 * precision + ( *p++ - '0' );
                 }
             }

             /* parse 'h', 'l' and 'll' data type modifiers */

             if ( *p == 'h' || *p == 'l' )
             {
                 data_type_modifier = *p;
                 p++;
                 if ( data_type_modifier == 'l' && *p == 'l' )
                 {
                     /* double l = long long */
#ifdef SNPRINTF_LONGLONG_SUPPORT
                     data_type_modifier = '2';     /* double l encoded as '2' */
#else
                     data_type_modifier = 'l';     /* treat it as single 'l' */
#endif
                     p++;
                 }
             }
             fmt_spec = *p;

             /* common synonyms: */

             switch ( fmt_spec )
             {
                 case 'i':
                     fmt_spec = 'd';
                     break;

                 case 'D':
                     fmt_spec = 'd';
                     data_type_modifier = 'l';
                     break;

                 case 'U':
                     fmt_spec = 'u';
                     data_type_modifier = 'l';
                     break;

                 case 'O':
                     fmt_spec = 'o';
                     data_type_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':
                     data_type_modifier = '\0';  

                     /* wint_t and wchar_t not supported */
                     /* the result of zero padding flag with non-numeric
                        format is undefined */
                     /* Solaris and HPUX 10 does zero padding in this case,
                        Digital Unix not */
#ifdef DIGITAL_UNIX_COMPATIBLE
                     zero_padding = 0;        /* turn zero padding off for
                                                 string formats */
#endif
                     str_arg_l = 1;

                     switch ( fmt_spec )
                     {
                         case '%':
                             str_arg = p;
                             break;

                         case 'c':
                         {
                             j = va_arg( ap, int );
                             str_arg = ( const char * ) &j;
                         }
                         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
                             {
                                 const char *q = memchr( str_arg, '\0',
                                                         ( size_t ) precision );
                                 str_arg_l = ! q ? precision : ( q - str_arg );
                             }
                             break;

                         default:
                             break;
                     }
                     break;

                 case 'd':
                 case 'o':
                 case 'u':
                 case 'x':
                 case 'X':
                 case 'p':
                     long_arg = 0;
                     int_arg = 0;
                     ptr_arg = NULL;

                     if ( fmt_spec == 'p' )
                     {
                         /* * HPUX 10:
                              An l, h, ll or L before any other conversion
                              character (other than d, i, o, u, 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, o, u, 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 data type modifiers even if it
                            represents 'll' */
#  else
                         if ( data_type_modifier == '2' )
                             data_type_modifier = '\0';
#  endif
#else
                         data_type_modifier = '\0';
#endif
                         ptr_arg = va_arg( ap, void * );
                         long_arg = ! ptr_arg ? 0 : 1;
                     } else {
                         switch ( data_type_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 );
                                 long_arg = int_arg;
                                 break;

                             case 'l':
                                 long_arg = va_arg( ap, long int );
                                 break;

#ifdef SNPRINTF_LONGLONG_SUPPORT
                             case '2':
                                 long_long_arg = va_arg( ap, long long int );

                                 /* only the sign of long_arg is guaranteed */

                                 if ( long_long_arg > 0 )
                                     long_arg = +1;
                                 else if ( long_long_arg < 0 )
                                     long_arg = -1;
                                 else
                                     long_arg = 0;
                                 break;
#endif
                         }
                     }

                     str_arg = tmp;
                     str_arg_l = 0;

                     /* NOTE:
                      *   For d, i, o, u, 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 and HPUX 10;
                      *   but not with Perl. */

#ifndef PERL_COMPATIBLE
                     if ( precision_specified )
                         zero_padding = 0;
#endif

                     if ( fmt_spec == 'd' )
                     {
                         if ( force_sign && long_arg >= 0 )
                             tmp[ str_arg_l++ ] =
                                                space_for_positive ? ' ' : '+';

                         /* Leave negative numbers for sprintf to handle,
                            to avoid handling tricky cases like
                            (short int)(-32768) */

                     }
                     else if ( alternative_form )
                     {
                         if (    long_arg != 0
                              && ( fmt_spec == 'x' || fmt_spec == 'X' ) )
                         {
                             tmp[ str_arg_l++ ] = '0';
                             tmp[ str_arg_l++ ] = fmt_spec; }
#ifdef HPUX_COMPATIBLE
                         else if ( fmt_spec == 'p'

                        /* HPUX 10: for an alternative 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. */
                                   && long_arg != 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 && long_arg == 0
#ifdef HPUX_BUG_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 it returns all zeroes. */
#endif
                         )
                     {
                         /* converted to null string */
                     }
                     else
                     {
                         char f[ 5 ];
                         int f_l = 0;

                         f[ f_l++ ] = '%';

                         if ( ! data_type_modifier )
                         {
                         }
                         else if ( data_type_modifier == '2' )
                         {
                             f[ f_l++ ] = 'l';
                             f[ f_l++ ] = 'l';
                         }
                         else
                             f[ f_l++ ] = data_type_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
                         {
                             switch ( data_type_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
                             }
                         }

                         if (    zero_padding_insertion_ind < str_arg_l
                              && tmp[ zero_padding_insertion_ind ] == '-' )
                             zero_padding_insertion_ind++;
                     }

                     {
                         int num_of_digits =
                                       str_arg_l - zero_padding_insertion_ind;

                         if ( alternative_form && fmt_spec == 'o'
#ifdef HPUX_COMPATIBLE                                  /* ("%#.o",0) -> ""  */
                              && ( str_arg_l > 0 )
#endif
#ifdef DIGITAL_UNIX_BUG_COMPATIBLE                      /* ("%#o",0) -> "00" */
#else
                              && ! ( zero_padding_insertion_ind < str_arg_l
                                     && tmp[zero_padding_insertion_ind] == '0' )
#endif
                             )
                         {
                             /* assure leading zero for alternative-form
                                octal numbers */

                             if (    ! precision_specified
                                  || precision < num_of_digits + 1 )
                             {
                                 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 format, keep format string
                              unchanged */

                     zero_padding = 0;   /* turn zero padding off for
                                            non-numeric formats */

#ifndef DIGITAL_UNIX_COMPATIBLE
                     justify_left = 1;
                     min_field_width = 0;                /* reset flags */
#endif
#ifdef PERL_COMPATIBLE
                     /* keep the entire format string unchanged */

                     str_arg = starting_p;
                     str_arg_l = p - starting_p;
#else

                     /* discard the unrecognized format, just keep the
                        unrecognized fmt char */

                     str_arg = p;
                     str_arg_l = 0;
#endif

                     if ( *p )
                         str_arg_l++;  /* include invalid fmt specifier if
                                          not at EOS */
                     break;
             }

             if ( *p )
                 p++;       /* step over the just processed format specifier */

             /* insert padding to the left as requested by min_field_width */

             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 )
                 {
                     int avail = ( int ) ( str_m - str_l );

                     if ( avail > 0 )
                     {      /* memset(str+str_l, zp, (n>avail?avail:n)); */
                         const char zp = zero_padding ? '0' : ' ';
                         int k;
                         char *r;

                         for ( r = str + str_l, k= ( n > avail ? avail : n );
                               k > 0; k-- )
                             *r++ = zp;
                     }
                     str_l += n;
                 }
             }

             /* zero padding as requested by the precision for numeric
                formats requred?*/

             if ( number_of_zeros_to_pad <= 0 )
             {
                 /* will not copy first part of numeric here,   *
                  * 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 )
                 {
                     int avail = ( int ) ( str_m - str_l );

                     if ( avail > 0 )
                         memcpy( str + str_l, str_arg,
                                 ( size_t ) ( n > avail ? avail : n ) );
                     str_l += n;
                 }

                 /* insert zero padding as requested by the precision */

                 n = number_of_zeros_to_pad;
                 if ( n > 0 )
                 {
                     int avail = ( int ) ( str_m - str_l );

                     if ( avail > 0 )
                     {     /* memset(str+str_l, '0', (n>avail?avail:n)); */
                         int k;
                         char *r;

                         for ( r = str + str_l, k = ( n > avail ? avail : n );
                               k > 0; k-- )
                             *r++ = '0';
                     }
                     str_l += n;
                 }
             }

             /* insert formatted string (or unmodified format for unknown
                formats) */

             {
                 int n = str_arg_l - zero_padding_insertion_ind;

                 if ( n > 0 )
                 {
                     int avail = ( int ) ( str_m - str_l );

                     if ( avail > 0 )
                         memcpy( str + str_l,
                                 str_arg + zero_padding_insertion_ind,
                                 ( size_t ) ( 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 )
                 {
                     int avail = ( int ) ( str_m - str_l );

                     if ( avail > 0 )
                     {     /* memset(str+str_l, ' ', (n>avail?avail:n)); */
                         int k;
                         char *r;

                         for ( r = str + str_l, k= n > avail ? avail : n;
                               k > 0;  k-- )
                             *r++ = ' ';
                     }
                     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 */
         str[ str_l <= str_m - 1 ? str_l : str_m -1 ] = '\0';
     }

     return str_l;    /* 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 */
}
#endif


/*
 * Local variables:
 * tab-width: 4
 * indent-tabs-mode: nil
 * End:
 */
