[mmh] / sbr / snprintf.c

/*
 * snprintf.c -- formatted output to a string
 *
 * This is an implementation of snprintf() and vsnprintf()
 * taken from the Apache web server.  This is only used on
 * systems which do not have a native version.
 */

/* ====================================================================
 * Copyright (c) 1995-1999 The Apache Group.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * 4. The names "Apache Server" and "Apache Group" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the Apache Group
 *    for use in the Apache HTTP server project (http://www.apache.org/)."
 *
 * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE APACHE GROUP OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Group and was originally based
 * on public domain software written at the National Center for
 * Supercomputing Applications, University of Illinois, Urbana-Champaign.
 * For more information on the Apache Group and the Apache HTTP server
 * project, please see <http://www.apache.org/>.
 *
 * This code is based on, and used with the permission of, the
 * SIO stdio-replacement strx_* functions by Panos Tsirigotis
 * <panos@alumni.cs.colorado.edu> for xinetd.
 */

#include <stdio.h>
#include <ctype.h>
#include <sys/types.h>
#include <stdarg.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <netinet/in.h>

typedef enum {
        NO = 0, YES = 1
} boolean_e;

#ifndef FALSE
# define FALSE 0
#endif
#ifndef TRUE
# define TRUE 1
#endif
#define NUL '\0'
#define INT_NULL ((int *)0)
#define WIDE_INT long

typedef struct {
        char *curpos;
        char *endpos;
} ap_vformatter_buff;

typedef WIDE_INT wide_int;
typedef unsigned WIDE_INT u_wide_int;
typedef int bool_int;

#define S_NULL "(null)"
#define S_NULL_LEN 6

#define FLOAT_DIGITS 6
#define EXPONENT_LENGTH 10

/* These macros allow correct support of 8-bit characters on systems which
 * support 8-bit characters.  Pretty dumb how the cast is required, but
 * that's legacy libc for ya.  These new macros do not support EOF like
 * the standard macros do.  Tough.
 */
#define ap_isalpha(c) (isalpha(((unsigned char)(c))))
#define ap_isdigit(c) (isdigit(((unsigned char)(c))))
#define ap_islower(c) (islower(((unsigned char)(c))))

/*
 * NUM_BUF_SIZE is the size of the buffer used for arithmetic conversions
 *
 * XXX: this is a magic number; do not decrease it
 */
#define NUM_BUF_SIZE 512

/*
 * cvt.c - IEEE floating point formatting routines for FreeBSD
 * from GNU libc-4.6.27.  Modified to be thread safe.
 */

/*
 *    ap_ecvt converts to decimal
 *      the number of digits is specified by ndigit
 *      decpt is set to the position of the decimal point
 *      sign is set to 0 for positive, 1 for negative
 */

#define NDIG 80

/* buf must have at least NDIG bytes */
static char *ap_cvt(double arg, int ndigits, int *decpt, int *sign, int eflag, char *buf)
{
        register int r2;
        double fi, fj;
        register char *p, *p1;

        if (ndigits >= NDIG - 1)
                ndigits = NDIG - 2;
        r2 = 0;
        *sign = 0;
        p = &buf[0];
        if (arg < 0) {
                *sign = 1;
                arg = -arg;
        }
        arg = modf(arg, &fi);
        p1 = &buf[NDIG];
        /*
         * Do integer part
         */
        if (fi != 0) {
                p1 = &buf[NDIG];
                while (fi != 0) {
                        fj = modf(fi / 10, &fi);
                        *--p1 = (int) ((fj + .03) * 10) + '0';
                        r2++;
                }
                while (p1 < &buf[NDIG])
                        *p++ = *p1++;
        } else if (arg > 0) {
                while ((fj = arg * 10) < 1) {
                        arg = fj;
                        r2--;
                }
        }
        p1 = &buf[ndigits];
        if (eflag == 0)
                p1 += r2;
        *decpt = r2;
        if (p1 < &buf[0]) {
                buf[0] = '\0';
                return (buf);
        }
        while (p <= p1 && p < &buf[NDIG]) {
                arg *= 10;
                arg = modf(arg, &fj);
                *p++ = (int) fj + '0';
        }
        if (p1 >= &buf[NDIG]) {
                buf[NDIG - 1] = '\0';
                return (buf);
        }
        p = p1;
        *p1 += 5;
        while (*p1 > '9') {
                *p1 = '0';
                if (p1 > buf)
                        ++ * --p1;
                else {
                        *p1 = '1';
                        (*decpt)++;
                        if (eflag == 0) {
                                if (p > buf)
                                        *p = '0';
                                p++;
                        }
                }
        }
        *p = '\0';
        return (buf);
}

static char *ap_ecvt(double arg, int ndigits, int *decpt, int *sign, char *buf)
{
        return (ap_cvt(arg, ndigits, decpt, sign, 1, buf));
}

static char *ap_fcvt(double arg, int ndigits, int *decpt, int *sign, char *buf)
{
        return (ap_cvt(arg, ndigits, decpt, sign, 0, buf));
}

/*
 * ap_gcvt  - Floating output conversion to
 * minimal length string
 */

static char *ap_gcvt(double number, int ndigit, char *buf, boolean_e altform)
{
        int sign, decpt;
        register char *p1, *p2;
        register int i;
        char buf1[NDIG];

        p1 = ap_ecvt(number, ndigit, &decpt, &sign, buf1);
        p2 = buf;
        if (sign)
                *p2++ = '-';
        for (i = ndigit - 1; i > 0 && p1[i] == '0'; i--)
                ndigit--;
        if ((decpt >= 0 && decpt - ndigit > 4)
                || (decpt < 0 && decpt < -3)) {  /* use E-style */
                decpt--;
                *p2++ = *p1++;
                *p2++ = '.';
                for (i = 1; i < ndigit; i++)
                        *p2++ = *p1++;
                *p2++ = 'e';
                if (decpt < 0) {
                        decpt = -decpt;
                        *p2++ = '-';
                } else
                        *p2++ = '+';
                if (decpt / 100 > 0)
                        *p2++ = decpt / 100 + '0';
                if (decpt / 10 > 0)
                        *p2++ = (decpt % 100) / 10 + '0';
                *p2++ = decpt % 10 + '0';
        } else {
                if (decpt <= 0) {
                        if (*p1 != '0')
                                *p2++ = '.';
                        while (decpt < 0) {
                                decpt++;
                                *p2++ = '0';
                        }
                }
                for (i = 1; i <= ndigit; i++) {
                        *p2++ = *p1++;
                        if (i == decpt)
                                *p2++ = '.';
                }
                if (ndigit < decpt) {
                        while (ndigit++ < decpt)
                                *p2++ = '0';
                        *p2++ = '.';
                }
        }
        if (p2[-1] == '.' && !altform)
                p2--;
        *p2 = '\0';
        return (buf);
}

/*
 * The INS_CHAR macro inserts a character in the buffer and writes
 * the buffer back to disk if necessary
 * It uses the char pointers sp and bep:
 *      sp points to the next available character in the buffer
 *      bep points to the end-of-buffer+1
 * While using this macro, note that the nextb pointer is NOT updated.
 *
 * NOTE: Evaluation of the c argument should not have any side-effects
 */
#define INS_CHAR(c, sp, bep, cc) \
        { \
                if (sp >= bep) { \
                        vbuff->curpos = sp; \
                        if (flush_func(vbuff)) \
                                return -1; \
                        sp = vbuff->curpos; \
                        bep = vbuff->endpos; \
                } \
                *sp++ = (c); \
                cc++; \
        }

#define NUM( c ) ( c - '0' )

#define STR_TO_DEC( str, num ) \
        num = NUM( *str++ ) ; \
        while ( ap_isdigit( *str ) ) \
        { \
                num *= 10 ; \
                num += NUM( *str++ ) ; \
        }

/*
 * This macro does zero padding so that the precision
 * requirement is satisfied. The padding is done by
 * adding '0's to the left of the string that is going
 * to be printed.
 */
#define FIX_PRECISION( adjust, precision, s, s_len ) \
        if ( adjust ) \
                while ( s_len < precision ) \
                { \
                        *--s = '0' ; \
                        s_len++ ; \
                }

/*
 * Macro that does padding. The padding is done by printing
 * the character ch.
 */
#define PAD( width, len, ch ) do \
        { \
                INS_CHAR( ch, sp, bep, cc ) ; \
                width-- ; \
        } \
        while ( width > len )

/*
 * Prefix the character ch to the string str
 * Increase length
 * Set the has_prefix flag
 */
#define PREFIX( str, length, ch ) *--str = ch ; length++ ; has_prefix = YES


/*
 * Convert num to its decimal format.
 * Return value:
 *   - a pointer to a string containing the number (no sign)
 *   - len contains the length of the string
 *   - is_negative is set to TRUE or FALSE depending on the sign
 *     of the number (always set to FALSE if is_unsigned is TRUE)
 *
 * The caller provides a buffer for the string: that is the buf_end argument
 * which is a pointer to the END of the buffer + 1 (i.e. if the buffer
 * is declared as buf[ 100 ], buf_end should be &buf[ 100 ])
 */
static char *conv_10(register wide_int num, register bool_int is_unsigned,
         register bool_int *is_negative, char *buf_end,
         register int *len)
{
        register char *p = buf_end;
        register u_wide_int magnitude;

        if (is_unsigned) {
                magnitude = (u_wide_int) num;
                *is_negative = FALSE;
        } else {
                *is_negative = (num < 0);

                /*
                 * On a 2's complement machine, negating the most negative integer
                 * results in a number that cannot be represented as a signed integer.
                 * Here is what we do to obtain the number's magnitude:
                 *   a. add 1 to the number
                 *   b. negate it (becomes positive)
                 *   c. convert it to unsigned
                 *   d. add 1
                 */
                if (*is_negative) {
                        wide_int t = num + 1;

                        magnitude = ((u_wide_int) -t) + 1;
                } else
                        magnitude = (u_wide_int) num;
        }

        /*
         * We use a do-while loop so that we write at least 1 digit
         */
        do {
                register u_wide_int new_magnitude = magnitude / 10;

                *--p = (char) (magnitude - new_magnitude * 10 + '0');
                magnitude = new_magnitude;
        }
        while (magnitude);

        *len = buf_end - p;
        return (p);
}



static char *conv_in_addr(struct in_addr *ia, char *buf_end, int *len)
{
        unsigned addr = ntohl(ia->s_addr);
        char *p = buf_end;
        bool_int is_negative;
        int sub_len;

        p = conv_10((addr & 0x000000FF)  , TRUE, &is_negative, p, &sub_len);
        *--p = '.';
        p = conv_10((addr & 0x0000FF00) >>  8, TRUE, &is_negative, p, &sub_len);
        *--p = '.';
        p = conv_10((addr & 0x00FF0000) >> 16, TRUE, &is_negative, p, &sub_len);
        *--p = '.';
        p = conv_10((addr & 0xFF000000) >> 24, TRUE, &is_negative, p, &sub_len);

        *len = buf_end - p;
        return (p);
}



static char *conv_sockaddr_in(struct sockaddr_in *si, char *buf_end, int *len)
{
        char *p = buf_end;
        bool_int is_negative;
        int sub_len;

        p = conv_10(ntohs(si->sin_port), TRUE, &is_negative, p, &sub_len);
        *--p = ':';
        p = conv_in_addr(&si->sin_addr, p, &sub_len);

        *len = buf_end - p;
        return (p);
}



/*
 * Convert a floating point number to a string formats 'f', 'e' or 'E'.
 * The result is placed in buf, and len denotes the length of the string
 * The sign is returned in the is_negative argument (and is not placed
 * in buf).
 */
static char *conv_fp(register char format, register double num,
        boolean_e add_dp, int precision, bool_int *is_negative,
        char *buf, int *len)
{
        register char *s = buf;
        register char *p;
        int decimal_point;
        char buf1[NDIG];

        if (format == 'f')
                p = ap_fcvt(num, precision, &decimal_point, is_negative, buf1);
        else  /* either e or E format */
                p = ap_ecvt(num, precision + 1, &decimal_point, is_negative, buf1);

        /*
         * Check for Infinity and NaN
         */
        if (ap_isalpha(*p)) {
                *len = strlen(strcpy(buf, p));
                *is_negative = FALSE;
                return (buf);
        }

        if (format == 'f') {
                if (decimal_point <= 0) {
                        *s++ = '0';
                        if (precision > 0) {
                                *s++ = '.';
                                while (decimal_point++ < 0)
                                        *s++ = '0';
                        } else if (add_dp)
                                *s++ = '.';
                } else {
                        while (decimal_point-- > 0)
                                *s++ = *p++;
                        if (precision > 0 || add_dp)
                                *s++ = '.';
                }
        } else {
                *s++ = *p++;
                if (precision > 0 || add_dp)
                        *s++ = '.';
        }

        /*
         * copy the rest of p, the NUL is NOT copied
         */
        while (*p)
                *s++ = *p++;

        if (format != 'f') {
                char temp[EXPONENT_LENGTH];  /* for exponent conversion */
                int t_len;
                bool_int exponent_is_negative;

                *s++ = format;  /* either e or E */
                decimal_point--;
                if (decimal_point != 0) {
                        p = conv_10((wide_int) decimal_point, FALSE,
                                &exponent_is_negative, &temp[EXPONENT_LENGTH],
                                &t_len);
                        *s++ = exponent_is_negative ? '-' : '+';

                        /*
                         * Make sure the exponent has at least 2 digits
                         */
                        if (t_len == 1)
                                *s++ = '0';
                        while (t_len--)
                                *s++ = *p++;
                } else {
                        *s++ = '+';
                        *s++ = '0';
                        *s++ = '0';
                }
        }

        *len = s - buf;
        return (buf);
}


/*
 * Convert num to a base X number where X is a power of 2. nbits determines X.
 * For example, if nbits is 3, we do base 8 conversion
 * Return value:
 *      a pointer to a string containing the number
 *
 * The caller provides a buffer for the string: that is the buf_end argument
 * which is a pointer to the END of the buffer + 1 (i.e. if the buffer
 * is declared as buf[ 100 ], buf_end should be &buf[ 100 ])
 */
static char *conv_p2(register u_wide_int num, register int nbits,
        char format, char *buf_end, register int *len)
{
        register int mask = (1 << nbits) - 1;
        register char *p = buf_end;
        static const char low_digits[] = "0123456789abcdef";
        static const char upper_digits[] = "0123456789ABCDEF";
        register const char *digits = (format == 'X') ? upper_digits : low_digits;

        do {
                *--p = digits[num & mask];
                num >>= nbits;
        }
        while (num);

        *len = buf_end - p;
        return (p);
}


/*
 * Do format conversion placing the output in buffer
 */
int ap_vformatter(int (*flush_func)(ap_vformatter_buff *),
        ap_vformatter_buff *vbuff, const char *fmt, va_list ap)
{
        register char *sp;
        register char *bep;
        register int cc = 0;
        register int i;

        register char *s = NULL;
        char *q;
        int s_len;

        register int min_width = 0;
        int precision = 0;
        enum {
                LEFT, RIGHT
        } adjust;
        char pad_char;
        char prefix_char;

        double fp_num;
        wide_int i_num = (wide_int) 0;
        u_wide_int ui_num;

        char num_buf[NUM_BUF_SIZE];
        char char_buf[2];  /* for printing %% and %<unknown> */

        /*
         * Flag variables
         */
        boolean_e is_long;
        boolean_e alternate_form;
        boolean_e print_sign;
        boolean_e print_blank;
        boolean_e adjust_precision;
        boolean_e adjust_width;
        bool_int is_negative;

        sp = vbuff->curpos;
        bep = vbuff->endpos;

        while (*fmt) {
                if (*fmt != '%') {
                        INS_CHAR(*fmt, sp, bep, cc);
                } else {
                        /*
                         * Default variable settings
                         */
                        adjust = RIGHT;
                        alternate_form = print_sign = print_blank = NO;
                        pad_char = ' ';
                        prefix_char = NUL;

                        fmt++;

                        /*
                         * Try to avoid checking for flags, width or precision
                         */
                        if (!ap_islower(*fmt)) {
                                /*
                                 * Recognize flags: -, #, BLANK, +
                                 */
                                for (;; fmt++) {
                                        if (*fmt == '-')
                                                adjust = LEFT;
                                        else if (*fmt == '+')
                                                print_sign = YES;
                                        else if (*fmt == '#')
                                                alternate_form = YES;
                                        else if (*fmt == ' ')
                                                print_blank = YES;
                                        else if (*fmt == '0')
                                                pad_char = '0';
                                        else
                                                break;
                                }

                                /*
                                 * Check if a width was specified
                                 */
                                if (ap_isdigit(*fmt)) {
                                        STR_TO_DEC(fmt, min_width);
                                        adjust_width = YES;
                                } else if (*fmt == '*') {
                                        min_width = va_arg(ap, int);
                                        fmt++;
                                        adjust_width = YES;
                                        if (min_width < 0) {
                                                adjust = LEFT;
                                                min_width = -min_width;
                                        }
                                } else
                                        adjust_width = NO;

                                /*
                                 * Check if a precision was specified
                                 *
                                 * XXX: an unreasonable amount of precision may be specified
                                 * resulting in overflow of num_buf. Currently we
                                 * ignore this possibility.
                                 */
                                if (*fmt == '.') {
                                        adjust_precision = YES;
                                        fmt++;
                                        if (ap_isdigit(*fmt)) {
                                                STR_TO_DEC(fmt, precision);
                                        } else if (*fmt == '*') {
                                                precision = va_arg(ap, int);
                                                fmt++;
                                                if (precision < 0)
                                                        precision = 0;
                                        } else
                                                precision = 0;
                                } else
                                        adjust_precision = NO;
                        } else
                                adjust_precision = adjust_width = NO;

                        /*
                         * Modifier check
                         */
                        if (*fmt == 'l') {
                                is_long = YES;
                                fmt++;
                        } else {
                                if (*fmt == 'h')  /* "short" backward compatibility */
                                        ++fmt;
                                is_long = NO;
                        }

                        /*
                         * Argument extraction and printing.
                         * First we determine the argument type.
                         * Then, we convert the argument to a string.
                         * On exit from the switch, s points to the string that
                         * must be printed, s_len has the length of the string
                         * The precision requirements, if any, are reflected in s_len.
                         *
                         * NOTE: pad_char may be set to '0' because of the 0 flag.
                         *   It is reset to ' ' by non-numeric formats
                         */
                        switch (*fmt) {
                        case 'u':
                                if (is_long)
                                        i_num = va_arg(ap, u_wide_int);
                                else
                                        i_num = (wide_int) va_arg(ap, unsigned int);
                                s = conv_10(i_num, 1, &is_negative,
                                                        &num_buf[NUM_BUF_SIZE], &s_len);
                                FIX_PRECISION(adjust_precision, precision, s, s_len);
                                break;

                        case 'd':
                        case 'i':
                                if (is_long)
                                        i_num = va_arg(ap, wide_int);
                                else
                                        i_num = (wide_int) va_arg(ap, int);
                                s = conv_10(i_num, 0, &is_negative,
                                                        &num_buf[NUM_BUF_SIZE], &s_len);
                                FIX_PRECISION(adjust_precision, precision, s, s_len);

                                if (is_negative)
                                        prefix_char = '-';
                                else if (print_sign)
                                        prefix_char = '+';
                                else if (print_blank)
                                        prefix_char = ' ';
                                break;


                        case 'o':
                                if (is_long)
                                        ui_num = va_arg(ap, u_wide_int);
                                else
                                        ui_num = (u_wide_int) va_arg(ap, unsigned int);
                                s = conv_p2(ui_num, 3, *fmt,
                                                        &num_buf[NUM_BUF_SIZE], &s_len);
                                FIX_PRECISION(adjust_precision, precision, s, s_len);
                                if (alternate_form && *s != '0') {
                                        *--s = '0';
                                        s_len++;
                                }
                                break;


                        case 'x':
                        case 'X':
                                if (is_long)
                                        ui_num = (u_wide_int) va_arg(ap, u_wide_int);
                                else
                                        ui_num = (u_wide_int) va_arg(ap, unsigned int);
                                s = conv_p2(ui_num, 4, *fmt,
                                                        &num_buf[NUM_BUF_SIZE], &s_len);
                                FIX_PRECISION(adjust_precision, precision, s, s_len);
                                if (alternate_form && i_num != 0) {
                                        *--s = *fmt;  /* 'x' or 'X' */
                                        *--s = '0';
                                        s_len += 2;
                                }
                                break;


                        case 's':
                                s = va_arg(ap, char *);
                                if (s != NULL) {
                                        s_len = strlen(s);
                                        if (adjust_precision && precision < s_len)
                                                s_len = precision;
                                }
                                else {
                                        s = S_NULL;
                                        s_len = S_NULL_LEN;
                                }
                                pad_char = ' ';
                                break;


                        case 'f':
                        case 'e':
                        case 'E':
                                fp_num = va_arg(ap, double);
                                /*
                                 * * We use &num_buf[ 1 ], so that we have room for the sign
                                 */
                                s = conv_fp(*fmt, fp_num, alternate_form,
                                                (adjust_precision == NO) ? FLOAT_DIGITS : precision,
                                                        &is_negative, &num_buf[1], &s_len);
                                if (is_negative)
                                        prefix_char = '-';
                                else if (print_sign)
                                        prefix_char = '+';
                                else if (print_blank)
                                        prefix_char = ' ';
                                break;


                        case 'g':
                        case 'G':
                                if (adjust_precision == NO)
                                        precision = FLOAT_DIGITS;
                                else if (precision == 0)
                                        precision = 1;
                                /*
                                 * * We use &num_buf[ 1 ], so that we have room for the sign
                                 */
                                s = ap_gcvt(va_arg(ap, double), precision, &num_buf[1],
                                                        alternate_form);
                                if (*s == '-')
                                        prefix_char = *s++;
                                else if (print_sign)
                                        prefix_char = '+';
                                else if (print_blank)
                                        prefix_char = ' ';

                                s_len = strlen(s);

                                if (alternate_form && (q = strchr(s, '.')) == NULL) {
                                        s[s_len++] = '.';
                                        s[s_len] = '\0'; /* delimit for following strchr() */
                                }
                                if (*fmt == 'G' && (q = strchr(s, 'e')) != NULL)
                                        *q = 'E';
                                break;


                        case 'c':
                                char_buf[0] = (char) (va_arg(ap, int));
                                s = &char_buf[0];
                                s_len = 1;
                                pad_char = ' ';
                                break;


                        case '%':
                                char_buf[0] = '%';
                                s = &char_buf[0];
                                s_len = 1;
                                pad_char = ' ';
                                break;


                        case 'n':
                                *(va_arg(ap, int *)) = cc;
                                break;

                                /*
                                 * This is where we extend the printf format, with a second
                                 * type specifier
                                 */
                        case 'p':
                                switch(*++fmt) {
                                        /*
                                         * If the pointer size is equal to the size of an unsigned
                                         * integer we convert the pointer to a hex number, otherwise
                                         * we print "%p" to indicate that we don't handle "%p".
                                         */
                                case 'p':
                                        ui_num = (u_wide_int) va_arg(ap, void *);

                                        if (sizeof(char *) <= sizeof(u_wide_int))
                                                                s = conv_p2(ui_num, 4, 'x',
                                                                                        &num_buf[NUM_BUF_SIZE], &s_len);
                                        else {
                                                s = "%p";
                                                s_len = 2;
                                                prefix_char = NUL;
                                        }
                                        pad_char = ' ';
                                        break;

                                        /* print a struct sockaddr_in as a.b.c.d:port */
                                case 'I':
                                        {
                                                struct sockaddr_in *si;

                                                si = va_arg(ap, struct sockaddr_in *);
                                                if (si != NULL) {
                                                        s = conv_sockaddr_in(si, &num_buf[NUM_BUF_SIZE], &s_len);
                                                        if (adjust_precision && precision < s_len)
                                                                s_len = precision;
                                                }
                                                else {
                                                        s = S_NULL;
                                                        s_len = S_NULL_LEN;
                                                }
                                                pad_char = ' ';
                                        }
                                        break;

                                        /* print a struct in_addr as a.b.c.d */
                                case 'A':
                                        {
                                                struct in_addr *ia;

                                                ia = va_arg(ap, struct in_addr *);
                                                if (ia != NULL) {
                                                        s = conv_in_addr(ia, &num_buf[NUM_BUF_SIZE], &s_len);
                                                        if (adjust_precision && precision < s_len)
                                                                s_len = precision;
                                                }
                                                else {
                                                        s = S_NULL;
                                                        s_len = S_NULL_LEN;
                                                }
                                                pad_char = ' ';
                                        }
                                        break;

                                case NUL:
                                        /* if %p ends the string, oh well ignore it */
                                        continue;

                                default:
                                        s = "bogus %p";
                                        s_len = 8;
                                        prefix_char = NUL;
                                        break;
                                }
                                break;

                        case NUL:
                                /*
                                 * The last character of the format string was %.
                                 * We ignore it.
                                 */
                                continue;


                                /*
                                 * The default case is for unrecognized %'s.
                                 * We print %<char> to help the user identify what
                                 * option is not understood.
                                 * This is also useful in case the user wants to pass
                                 * the output of format_converter to another function
                                 * that understands some other %<char> (like syslog).
                                 * Note that we can't point s inside fmt because the
                                 * unknown <char> could be preceded by width etc.
                                 */
                        default:
                                char_buf[0] = '%';
                                char_buf[1] = *fmt;
                                s = char_buf;
                                s_len = 2;
                                pad_char = ' ';
                                break;
                        }

                        if (prefix_char != NUL && s != S_NULL && s != char_buf) {
                                *--s = prefix_char;
                                s_len++;
                        }

                        if (adjust_width && adjust == RIGHT && min_width > s_len) {
                                if (pad_char == '0' && prefix_char != NUL) {
                                        INS_CHAR(*s, sp, bep, cc);
                                        s++;
                                        s_len--;
                                        min_width--;
                                }
                                PAD(min_width, s_len, pad_char);
                        }

                        /*
                         * Print the string s.
                         */
                        for (i = s_len; i != 0; i--) {
                                INS_CHAR(*s, sp, bep, cc);
                                s++;
                        }

                        if (adjust_width && adjust == LEFT && min_width > s_len)
                                PAD(min_width, s_len, pad_char);
                }
                fmt++;
        }
        vbuff->curpos = sp;
        return cc;
}


static int snprintf_flush(ap_vformatter_buff *vbuff)
{
        /* if the buffer fills we have to abort immediately, there is no way
         * to "flush" a snprintf... there's nowhere to flush it to.
         */
        return -1;
}


int snprintf(char *buf, size_t len, const char *format,...)
{
        int cc;
        va_list ap;
        ap_vformatter_buff vbuff;

        if (len == 0)
                return 0;

        /* save one byte for nul terminator */
        vbuff.curpos = buf;
        vbuff.endpos = buf + len - 1;
        va_start(ap, format);
        cc = ap_vformatter(snprintf_flush, &vbuff, format, ap);
        va_end(ap);
        *vbuff.curpos = '\0';
        return (cc == -1) ? len : cc;
}


int vsnprintf(char *buf, size_t len, const char *format, va_list ap)
{
        int cc;
        ap_vformatter_buff vbuff;

        if (len == 0)
                return 0;

        /* save one byte for nul terminator */
        vbuff.curpos = buf;
        vbuff.endpos = buf + len - 1;
        cc = ap_vformatter(snprintf_flush, &vbuff, format, ap);
        *vbuff.curpos = '\0';
        return (cc == -1) ? len : cc;
}