network_cmds-543.200.16.tar.gz

[apple/network_cmds.git] / unbound / compat / snprintf.c

/* snprintf - compatibility implementation of snprintf, vsnprintf
 *
 * Copyright (c) 2013, NLnet Labs. All rights reserved.
 *
 * This software is open source.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * 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.
 * 
 * Neither the name of the NLNET LABS nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS 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 COPYRIGHT
 * HOLDER OR 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.
 */

#include "config.h"
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
#include <errno.h>
#ifdef HAVE_STDINT_H
#include <stdint.h>
#endif

/* for test */
/* #define SNPRINTF_TEST 1 */
#ifdef SNPRINTF_TEST
#define snprintf my_snprintf
#define vsnprintf my_vsnprintf
#endif /* SNPRINTF_TEST */

int snprintf(char* str, size_t size, const char* format, ...);
int vsnprintf(char* str, size_t size, const char* format, va_list arg);

/**
 * Very portable snprintf implementation, limited in functionality,
 * esp. for %[capital] %[nonportable] and so on.  Reduced float functionality,
 * mostly in formatting and range (e+-16), for %f and %g.
 *
 * %s, %d, %u, %i, %x, %c, %n and %% are fully supported.
 *   This includes width, precision, flags 0- +, and *(arg for wid,prec).
 * %f, %g, %m, %p have reduced support, support for wid,prec,flags,*, but
 *   less floating point range, no %e formatting for %g.
 */
int snprintf(char* str, size_t size, const char* format, ...)
{
        int r;
        va_list args;
        va_start(args, format);
        r = vsnprintf(str, size, format, args);
        va_end(args);
        return r;
}

/** add padding to string */
static void
print_pad(char** at, size_t* left, int* ret, char p, int num)
{
        while(num--) {
                if(*left > 1) {
                        *(*at)++ = p;
                        (*left)--;
                }
                (*ret)++;
        }
}

/** get negative symbol, 0 if none */
static char
get_negsign(int negative, int plus, int space)
{
        if(negative)
                return '-';
        if(plus)
                return '+';
        if(space)
                return ' ';
        return 0;
}

#define PRINT_DEC_BUFSZ 32 /* 20 is enough for 64 bit decimals */
/** print decimal into buffer, returns length */
static int
print_dec(char* buf, int max, unsigned int value)
{
        int i = 0;
        if(value == 0) {
                if(max > 0) {
                        buf[0] = '0';
                        i = 1;
                }
        } else while(value && i < max) {
                buf[i++] = '0' + value % 10;
                value /= 10;
        }
        return i;
}

/** print long decimal into buffer, returns length */
static int
print_dec_l(char* buf, int max, unsigned long value)
{
        int i = 0;
        if(value == 0) {
                if(max > 0) {
                        buf[0] = '0';
                        i = 1;
                }
        } else while(value && i < max) {
                buf[i++] = '0' + value % 10;
                value /= 10;
        }
        return i;
}

/** print long decimal into buffer, returns length */
static int
print_dec_ll(char* buf, int max, unsigned long long value)
{
        int i = 0;
        if(value == 0) {
                if(max > 0) {
                        buf[0] = '0';
                        i = 1;
                }
        } else while(value && i < max) {
                buf[i++] = '0' + value % 10;
                value /= 10;
        }
        return i;
}

/** print hex into buffer, returns length */
static int
print_hex(char* buf, int max, unsigned int value)
{
        const char* h = "0123456789abcdef";
        int i = 0;
        if(value == 0) {
                if(max > 0) {
                        buf[0] = '0';
                        i = 1;
                }
        } else while(value && i < max) {
                buf[i++] = h[value & 0x0f];
                value >>= 4;
        }
        return i;
}

/** print long hex into buffer, returns length */
static int
print_hex_l(char* buf, int max, unsigned long value)
{
        const char* h = "0123456789abcdef";
        int i = 0;
        if(value == 0) {
                if(max > 0) {
                        buf[0] = '0';
                        i = 1;
                }
        } else while(value && i < max) {
                buf[i++] = h[value & 0x0f];
                value >>= 4;
        }
        return i;
}

/** print long long hex into buffer, returns length */
static int
print_hex_ll(char* buf, int max, unsigned long long value)
{
        const char* h = "0123456789abcdef";
        int i = 0;
        if(value == 0) {
                if(max > 0) {
                        buf[0] = '0';
                        i = 1;
                }
        } else while(value && i < max) {
                buf[i++] = h[value & 0x0f];
                value >>= 4;
        }
        return i;
}

/** copy string into result, reversed */
static void
spool_str_rev(char** at, size_t* left, int* ret, const char* buf, int len)
{
        int i = len;
        while(i) {
                if(*left > 1) {
                        *(*at)++ = buf[--i];
                        (*left)--;
                } else --i;
                (*ret)++;
        }
}

/** copy string into result */
static void
spool_str(char** at, size_t* left, int* ret, const char* buf, int len)
{
        int i;
        for(i=0; i<len; i++) {
                if(*left > 1) {
                        *(*at)++ = buf[i];
                        (*left)--;
                }
                (*ret)++;
        }
}

/** print number formatted */
static void
print_num(char** at, size_t* left, int* ret, int minw, int precision,
        int prgiven, int zeropad, int minus, int plus, int space,
        int zero, int negative, char* buf, int len)
{
        int w = len; /* excludes minus sign */
        char s = get_negsign(negative, plus, space);
        if(minus) {
                /* left adjust the number into the field, space padding */
                /* calc numw = [sign][zeroes][number] */
                int numw = w;
                if(precision == 0 && zero) numw = 0;
                if(numw < precision) numw = precision;
                if(s) numw++;

                /* sign */
                if(s) print_pad(at, left, ret, s, 1);

                /* number */
                if(precision == 0 && zero) {
                        /* "" for the number */
                } else {
                        if(w < precision)
                                print_pad(at, left, ret, '0', precision - w);
                        spool_str_rev(at, left, ret, buf, len);
                }
                /* spaces */
                if(numw < minw)
                        print_pad(at, left, ret, ' ', minw - numw);
        } else {
                /* pad on the left of the number */
                /* calculate numw has width of [sign][zeroes][number] */
                int numw = w;
                if(precision == 0 && zero) numw = 0;
                if(numw < precision) numw = precision;
                if(!prgiven && zeropad && numw < minw) numw = minw;
                else if(s) numw++;

                /* pad with spaces */
                if(numw < minw)
                        print_pad(at, left, ret, ' ', minw - numw);
                /* print sign (and one less zeropad if so) */
                if(s) {
                        print_pad(at, left, ret, s, 1);
                        numw--;
                }
                /* pad with zeroes */
                if(w < numw)
                        print_pad(at, left, ret, '0', numw - w);
                if(precision == 0 && zero)
                        return;
                /* print the characters for the value */
                spool_str_rev(at, left, ret, buf, len);
        }
}

/** print %d and %i */
static void
print_num_d(char** at, size_t* left, int* ret, int value,
        int minw, int precision, int prgiven, int zeropad, int minus,
        int plus, int space)
{
        char buf[PRINT_DEC_BUFSZ];
        int negative = (value < 0);
        int zero = (value == 0);
        int len = print_dec(buf, (int)sizeof(buf),
                (unsigned int)(negative?-value:value));
        print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
                plus, space, zero, negative, buf, len);
}

/** print %ld and %li */
static void
print_num_ld(char** at, size_t* left, int* ret, long value,
        int minw, int precision, int prgiven, int zeropad, int minus,
        int plus, int space)
{
        char buf[PRINT_DEC_BUFSZ];
        int negative = (value < 0);
        int zero = (value == 0);
        int len = print_dec_l(buf, (int)sizeof(buf),
                (unsigned long)(negative?-value:value));
        print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
                plus, space, zero, negative, buf, len);
}

/** print %lld and %lli */
static void
print_num_lld(char** at, size_t* left, int* ret, long long value,
        int minw, int precision, int prgiven, int zeropad, int minus,
        int plus, int space)
{
        char buf[PRINT_DEC_BUFSZ];
        int negative = (value < 0);
        int zero = (value == 0);
        int len = print_dec_ll(buf, (int)sizeof(buf),
                (unsigned long long)(negative?-value:value));
        print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
                plus, space, zero, negative, buf, len);
}

/** print %u */
static void
print_num_u(char** at, size_t* left, int* ret, unsigned int value,
        int minw, int precision, int prgiven, int zeropad, int minus,
        int plus, int space)
{
        char buf[PRINT_DEC_BUFSZ];
        int negative = 0;
        int zero = (value == 0);
        int len = print_dec(buf, (int)sizeof(buf), value);
        print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
                plus, space, zero, negative, buf, len);
}

/** print %lu */
static void
print_num_lu(char** at, size_t* left, int* ret, unsigned long value,
        int minw, int precision, int prgiven, int zeropad, int minus,
        int plus, int space)
{
        char buf[PRINT_DEC_BUFSZ];
        int negative = 0;
        int zero = (value == 0);
        int len = print_dec_l(buf, (int)sizeof(buf), value);
        print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
                plus, space, zero, negative, buf, len);
}

/** print %llu */
static void
print_num_llu(char** at, size_t* left, int* ret, unsigned long long value,
        int minw, int precision, int prgiven, int zeropad, int minus,
        int plus, int space)
{
        char buf[PRINT_DEC_BUFSZ];
        int negative = 0;
        int zero = (value == 0);
        int len = print_dec_ll(buf, (int)sizeof(buf), value);
        print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
                plus, space, zero, negative, buf, len);
}

/** print %x */
static void
print_num_x(char** at, size_t* left, int* ret, unsigned int value,
        int minw, int precision, int prgiven, int zeropad, int minus,
        int plus, int space)
{
        char buf[PRINT_DEC_BUFSZ];
        int negative = 0;
        int zero = (value == 0);
        int len = print_hex(buf, (int)sizeof(buf), value);
        print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
                plus, space, zero, negative, buf, len);
}

/** print %lx */
static void
print_num_lx(char** at, size_t* left, int* ret, unsigned long value,
        int minw, int precision, int prgiven, int zeropad, int minus,
        int plus, int space)
{
        char buf[PRINT_DEC_BUFSZ];
        int negative = 0;
        int zero = (value == 0);
        int len = print_hex_l(buf, (int)sizeof(buf), value);
        print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
                plus, space, zero, negative, buf, len);
}

/** print %llx */
static void
print_num_llx(char** at, size_t* left, int* ret, unsigned long long value,
        int minw, int precision, int prgiven, int zeropad, int minus,
        int plus, int space)
{
        char buf[PRINT_DEC_BUFSZ];
        int negative = 0;
        int zero = (value == 0);
        int len = print_hex_ll(buf, (int)sizeof(buf), value);
        print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
                plus, space, zero, negative, buf, len);
}

/** print %llp */
static void
print_num_llp(char** at, size_t* left, int* ret, void* value,
        int minw, int precision, int prgiven, int zeropad, int minus,
        int plus, int space)
{
        char buf[PRINT_DEC_BUFSZ];
        int negative = 0;
        int zero = (value == 0);
#if defined(UINTPTR_MAX) && defined(UINT32_MAX) && (UINTPTR_MAX == UINT32_MAX)
        /* avoid warning about upcast on 32bit systems */
        unsigned long long llvalue = (unsigned long)value;
#else
        unsigned long long llvalue = (unsigned long long)value;
#endif
        int len = print_hex_ll(buf, (int)sizeof(buf), llvalue);
        if(zero) {
                buf[0]=')';
                buf[1]='l';
                buf[2]='i';
                buf[3]='n';
                buf[4]='(';
                len = 5;
        } else {
                /* put '0x' in front of the (reversed) buffer result */
                if(len < PRINT_DEC_BUFSZ)
                        buf[len++] = 'x';
                if(len < PRINT_DEC_BUFSZ)
                        buf[len++] = '0';
        }
        print_num(at, left, ret, minw, precision, prgiven, zeropad, minus,
                plus, space, zero, negative, buf, len);
}

#define PRINT_FLOAT_BUFSZ 64 /* xx.yy with 20.20 about the max */
/** spool remainder after the decimal point to buffer, in reverse */
static int
print_remainder(char* buf, int max, double r, int prec)
{
        unsigned long long cap = 1;
        unsigned long long value;
        int len, i;
        if(prec > 19) prec = 19; /* max we can do */
        if(max < prec) return 0;
        for(i=0; i<prec; i++) {
                cap *= 10;
        }
        r *= (double)cap;
        value = (unsigned long long)r;
        /* see if we need to round up */
        if(((unsigned long long)((r - (double)value)*10.0)) >= 5) {
                value++;
                /* that might carry to numbers before the comma, if so,
                 * just ignore that rounding. failure because 64bitprintout */
                if(value >= cap)
                        value = cap-1;
        }
        len = print_dec_ll(buf, max, value);
        while(len < prec) { /* pad with zeroes, e.g. if 0.0012 */
                buf[len++] = '0';
        }
        if(len < max)
                buf[len++] = '.';
        return len;
}

/** spool floating point to buffer */
static int
print_float(char* buf, int max, double value, int prec)
{
        /* as xxx.xxx  if prec==0, no '.', with prec decimals after . */
        /* no conversion for NAN and INF, because we do not want to require
           linking with -lm. */
        /* Thus, the conversions use 64bit integers to convert the numbers,
         * which makes 19 digits before and after the decimal point the max */
        unsigned long long whole = (unsigned long long)value;
        double remain = value - (double)whole;
        int len = 0;
        if(prec != 0)
                len = print_remainder(buf, max, remain, prec);
        len += print_dec_ll(buf+len, max-len, whole);
        return len;
}

/** print %f */
static void
print_num_f(char** at, size_t* left, int* ret, double value,
        int minw, int precision, int prgiven, int zeropad, int minus,
        int plus, int space)
{
        char buf[PRINT_FLOAT_BUFSZ];
        int negative = (value < 0);
        int zero = 0;
        int len;
        if(!prgiven) precision = 6;
        len = print_float(buf, (int)sizeof(buf), negative?-value:value,
                precision);
        print_num(at, left, ret, minw, 1, 0, zeropad, minus,
                plus, space, zero, negative, buf, len);
}

/* rudimentary %g support */
static int
print_float_g(char* buf, int max, double value, int prec)
{
        unsigned long long whole = (unsigned long long)value;
        double remain = value - (double)whole;
        int before = 0;
        int len = 0;

        /* number of digits before the decimal point */
        while(whole > 0) {
                before++;
                whole /= 10;
        }
        whole = (unsigned long long)value;

        if(prec > before && remain != 0.0) {
                /* see if the last decimals are zero, if so, skip them */
                len = print_remainder(buf, max, remain, prec-before);
                while(len > 0 && buf[0]=='0') {
                        memmove(buf, buf+1, --len);
                }
        }
        len += print_dec_ll(buf+len, max-len, whole);
        return len;
}


/** print %g */
static void
print_num_g(char** at, size_t* left, int* ret, double value,
        int minw, int precision, int prgiven, int zeropad, int minus,
        int plus, int space)
{
        char buf[PRINT_FLOAT_BUFSZ];
        int negative = (value < 0);
        int zero = 0;
        int len;
        if(!prgiven) precision = 6;
        if(precision == 0) precision = 1;
        len = print_float_g(buf, (int)sizeof(buf), negative?-value:value,
                precision);
        print_num(at, left, ret, minw, 1, 0, zeropad, minus,
                plus, space, zero, negative, buf, len);
}


/** strnlen (compat implementation) */
static int
my_strnlen(const char* s, int max)
{
        int i;
        for(i=0; i<max; i++)
                if(s[i]==0)
                        return i;
        return max;
}

/** print %s */
static void
print_str(char** at, size_t* left, int* ret, char* s,
        int minw, int precision, int prgiven, int minus)
{
        int w;
        /* with prec: no more than x characters from this string, stop at 0 */
        if(prgiven)
                w = my_strnlen(s, precision);
        else    w = (int)strlen(s); /* up to the nul */
        if(w < minw && !minus)
                print_pad(at, left, ret, ' ', minw - w);
        spool_str(at, left, ret, s, w);
        if(w < minw && minus)
                print_pad(at, left, ret, ' ', minw - w);
}

/** print %c */
static void
print_char(char** at, size_t* left, int* ret, int c,
        int minw, int minus)
{
        if(1 < minw && !minus)
                print_pad(at, left, ret, ' ', minw - 1);
        print_pad(at, left, ret, c, 1);
        if(1 < minw && minus)
                print_pad(at, left, ret, ' ', minw - 1);
}


/** 
 * Print to string.
 * str: string buffer for result. result will be null terminated.
 * size: size of the buffer. null is put inside buffer.
 * format: printf format string.
 * arg: '...' arguments to print.
 * returns number of characters. a null is printed after this.
 * return number of bytes that would have been written
 *         if the buffer had been large enough.
 * 
 * supported format specifiers:
 *      %s, %u, %d, %x, %i, %f, %g, %c, %p, %n.
 *      length: l, ll (for d, u, x).
 *      precision: 6.6d (for d, u, x)
 *              %f, %g precisions, 0.3f
 *              %20s, '.*s'
 *      and %%.
 */
int vsnprintf(char* str, size_t size, const char* format, va_list arg)
{
        char* at = str;
        size_t left = size;
        int ret = 0;
        const char* fmt = format;
        int conv, minw, precision, prgiven, zeropad, minus, plus, space, length;
        while(*fmt) {
                /* copy string before % */
                while(*fmt && *fmt!='%') {
                        if(left > 1) {
                                *at++ = *fmt++;
                                left--;
                        } else fmt++;
                        ret++;
                }
                
                /* see if we are at end */
                if(!*fmt) break;

                /* fetch next argument % designation from format string */
                fmt++; /* skip the '%' */

                /********************************/
                /* get the argument designation */
                /********************************/
                /* we must do this vararg stuff inside this function for
                 * portability.  Hence, get_designation, and print_designation
                 * are not their own functions. */

                /* printout designation:
                 * conversion specifier: x, d, u, s, c, n, m, p
                 * flags: # not supported
                 *        0 zeropad (on the left)
                 *        - left adjust (right by default)
                 *        ' ' printspace for positive number (in - position).
                 *        + alwayssign
                 * fieldwidth: [1-9][0-9]* minimum field width.
                 *      if this is * then type int next argument specifies the minwidth.
                 *      if this is negative, the - flag is set (with positive width).
                 * precision: period[digits]*, %.2x.
                 *      if this is * then type int next argument specifies the precision.
                 *      just '.' or negative value means precision=0.
                 *              this is mindigits to print for d, i, u, x
                 *              this is aftercomma digits for f
                 *              this is max number significant digits for g
                 *              maxnumber characters to be printed for s
                 * length: 0-none (int), 1-l (long), 2-ll (long long)
                 *      notsupported: hh (char), h (short), L (long double), q, j, z, t
                 * Does not support %m$ and *m$ argument designation as array indices.
                 * Does not support %#x
                 *
                 */
                minw = 0;
                precision = 1;
                prgiven = 0;
                zeropad = 0;
                minus = 0;
                plus = 0;
                space = 0;
                length = 0;

                /* get flags in any order */
                for(;;) {
                        if(*fmt == '0')
                                zeropad = 1;
                        else if(*fmt == '-')
                                minus = 1;
                        else if(*fmt == '+')
                                plus = 1;
                        else if(*fmt == ' ')
                                space = 1;
                        else break;
                        fmt++;
                }

                /* field width */
                if(*fmt == '*') {
                        fmt++; /* skip char */
                        minw = va_arg(arg, int);
                        if(minw < 0) {
                                minus = 1;
                                minw = -minw;
                        }
                } else while(*fmt >= '0' && *fmt <= '9') {
                        minw = minw*10 + (*fmt++)-'0';
                }

                /* precision */
                if(*fmt == '.') {
                        fmt++; /* skip period */
                        prgiven = 1;
                        precision = 0;
                        if(*fmt == '*') {
                                fmt++; /* skip char */
                                precision = va_arg(arg, int);
                                if(precision < 0)
                                        precision = 0;
                        } else while(*fmt >= '0' && *fmt <= '9') {
                                precision = precision*10 + (*fmt++)-'0';
                        }
                }

                /* length */
                if(*fmt == 'l') {
                        fmt++; /* skip char */
                        length = 1;
                        if(*fmt == 'l') {
                                fmt++; /* skip char */
                                length = 2;
                        }
                }

                /* get the conversion */
                if(!*fmt) conv = 0;
                else    conv = *fmt++;

                /***********************************/
                /* print that argument designation */
                /***********************************/
                switch(conv) {
                case 'i':
                case 'd':
                        if(length == 0)
                            print_num_d(&at, &left, &ret, va_arg(arg, int),
                                minw, precision, prgiven, zeropad, minus, plus, space);
                        else if(length == 1)
                            print_num_ld(&at, &left, &ret, va_arg(arg, long),
                                minw, precision, prgiven, zeropad, minus, plus, space);
                        else if(length == 2)
                            print_num_lld(&at, &left, &ret,
                                va_arg(arg, long long),
                                minw, precision, prgiven, zeropad, minus, plus, space);
                        break;
                case 'u':
                        if(length == 0)
                            print_num_u(&at, &left, &ret,
                                va_arg(arg, unsigned int),
                                minw, precision, prgiven, zeropad, minus, plus, space);
                        else if(length == 1)
                            print_num_lu(&at, &left, &ret,
                                va_arg(arg, unsigned long),
                                minw, precision, prgiven, zeropad, minus, plus, space);
                        else if(length == 2)
                            print_num_llu(&at, &left, &ret,
                                va_arg(arg, unsigned long long),
                                minw, precision, prgiven, zeropad, minus, plus, space);
                        break;
                case 'x':
                        if(length == 0)
                            print_num_x(&at, &left, &ret,
                                va_arg(arg, unsigned int),
                                minw, precision, prgiven, zeropad, minus, plus, space);
                        else if(length == 1)
                            print_num_lx(&at, &left, &ret,
                                va_arg(arg, unsigned long),
                                minw, precision, prgiven, zeropad, minus, plus, space);
                        else if(length == 2)
                            print_num_llx(&at, &left, &ret,
                                va_arg(arg, unsigned long long),
                                minw, precision, prgiven, zeropad, minus, plus, space);
                        break;
                case 's':
                        print_str(&at, &left, &ret, va_arg(arg, char*),
                                minw, precision, prgiven, minus);
                        break;
                case 'c':
                        print_char(&at, &left, &ret, va_arg(arg, int),
                                minw, minus);
                        break;
                case 'n':
                        *va_arg(arg, int*) = ret;
                        break;
                case 'm':
                        print_str(&at, &left, &ret, strerror(errno),
                                minw, precision, prgiven, minus);
                        break;
                case 'p':
                        print_num_llp(&at, &left, &ret, va_arg(arg, void*),
                                minw, precision, prgiven, zeropad, minus, plus, space);
                        break;
                case '%':
                        print_pad(&at, &left, &ret, '%', 1);
                        break;
                case 'f':
                        print_num_f(&at, &left, &ret, va_arg(arg, double),
                                minw, precision, prgiven, zeropad, minus, plus, space);
                        break;
                case 'g':
                        print_num_g(&at, &left, &ret, va_arg(arg, double),
                                minw, precision, prgiven, zeropad, minus, plus, space);
                        break;
                /* unknown */
                default:
                case 0: break;
                }
        }

        /* zero terminate */
        if(left > 0)
                *at = 0;
        return ret;
}

#ifdef SNPRINTF_TEST

/** do tests */
#undef snprintf
#define DOTEST(bufsz, result, retval, ...) do { \
        char buf[bufsz]; \
        printf("now test %s\n", #__VA_ARGS__); \
        int r=my_snprintf(buf, sizeof(buf), __VA_ARGS__); \
        if(r != retval || strcmp(buf, result) != 0) { \
                printf("error test(%s) was \"%s\":%d\n", \
                        ""#bufsz", "#result", "#retval", "#__VA_ARGS__, \
                        buf, r); \
                exit(1); \
                } \
        r=snprintf(buf, sizeof(buf), __VA_ARGS__); \
        if(r != retval || strcmp(buf, result) != 0) { \
                printf("error test(%s) differs with system, \"%s\":%d\n", \
                        ""#bufsz", "#result", "#retval", "#__VA_ARGS__, \
                        buf, r); \
                exit(1); \
                } \
        printf("test(\"%s\":%d) passed\n", buf, r); \
        } while(0);

/** test program */
int main(void)
{
        int x = 0;

        /* bufsize, expectedstring, expectedretval, snprintf arguments */
        DOTEST(1024, "hello", 5, "hello");
        DOTEST(1024, "h", 1, "h");
        /* warning from gcc for format string, but it does work
         * DOTEST(1024, "", 0, ""); */

        DOTEST(3, "he", 5, "hello");
        DOTEST(1, "", 7, "%d", 7823089);

        /* test positive numbers */
        DOTEST(1024, "0", 1, "%d", 0);
        DOTEST(1024, "1", 1, "%d", 1);
        DOTEST(1024, "9", 1, "%d", 9);
        DOTEST(1024, "15", 2, "%d", 15);
        DOTEST(1024, "ab15cd", 6, "ab%dcd", 15);
        DOTEST(1024, "167", 3, "%d", 167);
        DOTEST(1024, "7823089", 7, "%d", 7823089);
        DOTEST(1024, " 12", 3, "%3d", 12);
        DOTEST(1024, "012", 3, "%.3d", 12);
        DOTEST(1024, "012", 3, "%3.3d", 12);
        DOTEST(1024, "012", 3, "%03d", 12);
        DOTEST(1024, " 012", 4, "%4.3d", 12);
        DOTEST(1024, "", 0, "%.0d", 0);

        /* test negative numbers */
        DOTEST(1024, "-1", 2, "%d", -1);
        DOTEST(1024, "-12", 3, "%3d", -12);
        DOTEST(1024, " -2", 3, "%3d", -2);
        DOTEST(1024, "-012", 4, "%.3d", -12);
        DOTEST(1024, "-012", 4, "%3.3d", -12);
        DOTEST(1024, "-012", 4, "%4.3d", -12);
        DOTEST(1024, " -012", 5, "%5.3d", -12);
        DOTEST(1024, "-12", 3, "%03d", -12);
        DOTEST(1024, "-02", 3, "%03d", -2);
        DOTEST(1024, "-15", 3, "%d", -15);
        DOTEST(1024, "-7307", 5, "%d", -7307);
        DOTEST(1024, "-12  ", 5, "%-5d", -12);
        DOTEST(1024, "-00012", 6, "%-.5d", -12);

        /* test + and space flags */
        DOTEST(1024, "+12", 3, "%+d", 12);
        DOTEST(1024, " 12", 3, "% d", 12);

        /* test %u */
        DOTEST(1024, "12", 2, "%u", 12);
        DOTEST(1024, "0", 1, "%u", 0);
        DOTEST(1024, "4294967295", 10, "%u", 0xffffffff);

        /* test %x */
        DOTEST(1024, "0", 1, "%x", 0);
        DOTEST(1024, "c", 1, "%x", 12);
        DOTEST(1024, "12ab34cd", 8, "%x", 0x12ab34cd);

        /* test %llu, %lld */
        DOTEST(1024, "18446744073709551615", 20, "%llu",
                (long long)0xffffffffffffffff);
        DOTEST(1024, "-9223372036854775808", 20, "%lld",
                (long long)0x8000000000000000);
        DOTEST(1024, "9223372036854775808", 19, "%llu",
                (long long)0x8000000000000000);

        /* test %s */
        DOTEST(1024, "hello", 5, "%s", "hello");
        DOTEST(1024, "     hello", 10, "%10s", "hello");
        DOTEST(1024, "hello     ", 10, "%-10s", "hello");
        DOTEST(1024, "he", 2, "%.2s", "hello");
        DOTEST(1024, "  he", 4, "%4.2s", "hello");
        DOTEST(1024, "   h", 4, "%4.2s", "h");

        /* test %c */
        DOTEST(1024, "a", 1, "%c", 'a');
        /* warning from gcc for format string, but it does work
           DOTEST(1024, "    a", 5, "%5c", 'a');
           DOTEST(1024, "a", 1, "%.0c", 'a'); */

        /* test %n */
        DOTEST(1024, "hello", 5, "hello%n", &x);
        if(x != 5) { printf("the %%n failed\n"); exit(1); }

        /* test %m */
        errno = 0;
        DOTEST(1024, "Success", 7, "%m");

        /* test %p */
        DOTEST(1024, "0x10", 4, "%p", (void*)0x10);
        DOTEST(1024, "(nil)", 5, "%p", (void*)0x0);

        /* test %% */
        DOTEST(1024, "%", 1, "%%");

        /* test %f */
        DOTEST(1024, "0.000000", 8, "%f", 0.0);
        DOTEST(1024, "0.00", 4, "%.2f", 0.0);
        /* differs, "-0.00" DOTEST(1024, "0.00", 4, "%.2f", -0.0); */
        DOTEST(1024, "234.00", 6, "%.2f", 234.005);
        DOTEST(1024, "8973497.1246", 12, "%.4f", 8973497.12456);
        DOTEST(1024, "-12.000000", 10, "%f", -12.0);
        DOTEST(1024, "6", 1, "%.0f", 6.0);

        DOTEST(1024, "6", 1, "%g", 6.0);
        DOTEST(1024, "6.1", 3, "%g", 6.1);
        DOTEST(1024, "6.15", 4, "%g", 6.15);

        /* These format strings are from the code of NSD, Unbound, ldns */

        DOTEST(1024, "abcdef", 6, "%s", "abcdef");
        DOTEST(1024, "005", 3, "%03u", 5);
        DOTEST(1024, "12345", 5, "%03u", 12345);
        DOTEST(1024, "5", 1, "%d", 5);
        DOTEST(1024, "(nil)", 5, "%p", NULL);
        DOTEST(1024, "12345", 5, "%ld", (long)12345);
        DOTEST(1024, "12345", 5, "%lu", (long)12345);
        DOTEST(1024, "       12345", 12, "%12u", (unsigned)12345);
        DOTEST(1024, "12345", 5, "%u", (unsigned)12345);
        DOTEST(1024, "12345", 5, "%llu", (unsigned long long)12345);
        DOTEST(1024, "12345", 5, "%x", 0x12345);
        DOTEST(1024, "12345", 5, "%llx", (long long)0x12345);
        DOTEST(1024, "012345", 6, "%6.6d", 12345);
        DOTEST(1024, "012345", 6, "%6.6u", 12345);
        DOTEST(1024, "1234.54", 7, "%g", 1234.54);
        DOTEST(1024, "123456789.54", 12, "%.12g", 123456789.54);
        DOTEST(1024, "3456789123456.54", 16, "%.16g", 3456789123456.54);
        /* %24g does not work with 24 digits, not enough accuracy,
         * the first 16 digits are correct */
        DOTEST(1024, "12345", 5, "%3.3d", 12345);
        DOTEST(1024, "000", 3, "%3.3d", 0);
        DOTEST(1024, "001", 3, "%3.3d", 1);
        DOTEST(1024, "012", 3, "%3.3d", 12);
        DOTEST(1024, "-012", 4, "%3.3d", -12);
        DOTEST(1024, "he", 2, "%.2s", "hello");
        DOTEST(1024, "helloworld", 10, "%s%s", "hello", "world");
        DOTEST(1024, "he", 2, "%.*s", 2, "hello");
        DOTEST(1024, "  hello", 7, "%*s", 7, "hello");
        DOTEST(1024, "hello  ", 7, "%*s", -7, "hello");
        DOTEST(1024, "0", 1, "%c", '0'); 
        DOTEST(1024, "A", 1, "%c", 'A'); 
        DOTEST(1024, "", 1, "%c", 0); 
        DOTEST(1024, "\010", 1, "%c", 8); 
        DOTEST(1024, "%", 1, "%%"); 
        DOTEST(1024, "0a", 2, "%02x", 0x0a); 
        DOTEST(1024, "bd", 2, "%02x", 0xbd); 
        DOTEST(1024, "12", 2, "%02ld", (long)12); 
        DOTEST(1024, "02", 2, "%02ld", (long)2); 
        DOTEST(1024, "02", 2, "%02u", (unsigned)2); 
        DOTEST(1024, "765432", 6, "%05u", (unsigned)765432); 
        DOTEST(1024, "10.234", 6, "%0.3f", 10.23421); 
        DOTEST(1024, "123456.234", 10, "%0.3f", 123456.23421); 
        DOTEST(1024, "123456789.234", 13, "%0.3f", 123456789.23421); 
        DOTEST(1024, "123456.23", 9, "%.2f", 123456.23421); 
        DOTEST(1024, "123456", 6, "%.0f", 123456.23421); 
        DOTEST(1024, "0123", 4, "%.4x", 0x0123); 
        DOTEST(1024, "00000123", 8, "%.8x", 0x0123); 
        DOTEST(1024, "ffeb0cde", 8, "%.8x", 0xffeb0cde); 
        DOTEST(1024, " 987654321", 10, "%10lu", (unsigned long)987654321); 
        DOTEST(1024, "   987654321", 12, "%12lu", (unsigned long)987654321); 
        DOTEST(1024, "987654321", 9, "%i", 987654321); 
        DOTEST(1024, "-87654321", 9, "%i", -87654321); 
        DOTEST(1024, "hello           ", 16, "%-16s", "hello"); 
        DOTEST(1024, "                ", 16, "%-16s", ""); 
        DOTEST(1024, "a               ", 16, "%-16s", "a"); 
        DOTEST(1024, "foobarfoobar    ", 16, "%-16s", "foobarfoobar"); 
        DOTEST(1024, "foobarfoobarfoobar", 18, "%-16s", "foobarfoobarfoobar"); 

        /* combined expressions */
        DOTEST(1024, "foo 1.0 size 512 edns", 21,
                "foo %s size %d %s%s", "1.0", 512, "", "edns");
        DOTEST(15, "foo 1.0 size 5", 21,
                "foo %s size %d %s%s", "1.0", 512, "", "edns");
        DOTEST(1024, "packet 1203ceff id", 18,
                "packet %2.2x%2.2x%2.2x%2.2x id", 0x12, 0x03, 0xce, 0xff);
        DOTEST(1024, "/tmp/testbound_123abcd.tmp", 26, "/tmp/testbound_%u%s%s.tmp", 123, "ab", "cd");
 
        return 0;
}
#endif /* SNPRINTF_TEST */