[OpenAFS-devel] Re: [OpenAFS] sprintf -> snprintf...
Russ Allbery
rra@stanford.edu
Sat, 28 Jun 2003 10:24:23 -0700
Jeffrey Hutzelman <jhutz@cmu.edu> writes:
> The use of the system sprintf for floating-point formats was purely an
> expediency; I needed something portable and didn't have the time or
> inclination to roll my own floating-point formatter. I'd be quite
> interested in using yours, provided there are no licensing problems.
Shouldn't be, as long as you don't need copyright assignments or anything.
It's the evolution of a public domain version originally posted to BUGTRAQ
a while back. I've only made a few bug fixes; most of the work was
already done before I picked it up by the mutt and Samba folks.
Other than floating point support, it sounds like the supported features
are roughly equivalent to what you have already (maybe slightly less), so
you probably just want to grab the floating point support and roll it in
to what you have.
It relies on HAVE_LONG_LONG and HAVE_LONG_DOUBLE from Autoconf probes.
Anyway, here it is:
/* $Id: snprintf.c,v 1.9 2002/08/29 04:07:22 rra Exp $
**
** Replacement for a missing snprintf or vsnprintf.
**
** The following implementation of snprintf was taken mostly verbatim from
** <http://www.fiction.net/~blong/programs/>; it is the version of snprintf
** used in Mutt.
**
** Please do not reformat or otherwise change this file more than
** necessary so that later merges with the original source are easy.
** Bug fixes and improvements should be sent back to the original author.
*/
/* If we're running the test suite, rename snprintf and vsnprintf to avoid
conflicts with the system version. */
#if TESTING
# define snprintf test_snprintf
# define vsnprintf test_vsnprintf
#endif
/*
* Copyright Patrick Powell 1995
* This code is based on code written by Patrick Powell (papowell@astart.com)
* It may be used for any purpose as long as this notice remains intact
* on all source code distributions
*/
/**************************************************************
* Original:
* Patrick Powell Tue Apr 11 09:48:21 PDT 1995
* A bombproof version of doprnt (dopr) included.
* Sigh. This sort of thing is always nasty do deal with. Note that
* the version here does not include floating point...
*
* snprintf() is used instead of sprintf() as it does limit checks
* for string length. This covers a nasty loophole.
*
* The other functions are there to prevent NULL pointers from
* causing nast effects.
*
* More Recently:
* Brandon Long <blong@fiction.net> 9/15/96 for mutt 0.43
* This was ugly. It is still ugly. I opted out of floating point
* numbers, but the formatter understands just about everything
* from the normal C string format, at least as far as I can tell from
* the Solaris 2.5 printf(3S) man page.
*
* Brandon Long <blong@fiction.net> 10/22/97 for mutt 0.87.1
* Ok, added some minimal floating point support, which means this
* probably requires libm on most operating systems. Don't yet
* support the exponent (e,E) and sigfig (g,G). Also, fmtint()
* was pretty badly broken, it just wasn't being exercised in ways
* which showed it, so that's been fixed. Also, formated the code
* to mutt conventions, and removed dead code left over from the
* original. Also, there is now a builtin-test, just compile with:
* gcc -DTEST_SNPRINTF -o snprintf snprintf.c -lm
* and run snprintf for results.
*
* Thomas Roessler <roessler@guug.de> 01/27/98 for mutt 0.89i
* The PGP code was using unsigned hexadecimal formats.
* Unfortunately, unsigned formats simply didn't work.
*
* Michael Elkins <me@cs.hmc.edu> 03/05/98 for mutt 0.90.8
* The original code assumed that both snprintf() and vsnprintf() were
* missing. Some systems only have snprintf() but not vsnprintf(), so
* the code is now broken down under HAVE_SNPRINTF and HAVE_VSNPRINTF.
*
* Andrew Tridgell (tridge@samba.org) Oct 1998
* fixed handling of %.0f
* added test for HAVE_LONG_DOUBLE
*
* Russ Allbery <rra@stanford.edu> 2000-08-26
* fixed return value to comply with C99
* fixed handling of snprintf(NULL, ...)
*
* Hrvoje Niksic <hniksic@arsdigita.com> 2000-11-04
* include <stdio.h> for NULL.
* added support for long long.
* don't declare argument types to (v)snprintf if stdarg is not used.
*
**************************************************************/
#include "config.h"
#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#ifndef NULL
# define NULL 0
#endif
/* varargs declarations: */
#include <stdarg.h>
#define HAVE_STDARGS /* let's hope that works everywhere (mj) */
#define VA_LOCAL_DECL va_list ap
#define VA_START(f) va_start(ap, f)
#define VA_SHIFT(v,t) ; /* no-op for ANSI */
#define VA_END va_end(ap)
#ifdef HAVE_LONG_DOUBLE
#define LDOUBLE long double
#else
#define LDOUBLE double
#endif
#ifdef HAVE_LONG_LONG
# define LLONG long long
#else
# define LLONG long
#endif
int snprintf (char *str, size_t count, const char *fmt, ...);
int vsnprintf (char *str, size_t count, const char *fmt, va_list arg);
static int dopr (char *buffer, size_t maxlen, const char *format,
va_list args);
static int fmtstr (char *buffer, size_t *currlen, size_t maxlen,
char *value, int flags, int min, int max);
static int fmtint (char *buffer, size_t *currlen, size_t maxlen,
LLONG value, int base, int min, int max, int flags);
static int fmtfp (char *buffer, size_t *currlen, size_t maxlen,
LDOUBLE fvalue, int min, int max, int flags);
static int dopr_outch (char *buffer, size_t *currlen, size_t maxlen, char c );
/*
* dopr(): poor man's version of doprintf
*/
/* format read states */
#define DP_S_DEFAULT 0
#define DP_S_FLAGS 1
#define DP_S_MIN 2
#define DP_S_DOT 3
#define DP_S_MAX 4
#define DP_S_MOD 5
#define DP_S_MOD_L 6
#define DP_S_CONV 7
#define DP_S_DONE 8
/* format flags - Bits */
#define DP_F_MINUS (1 << 0)
#define DP_F_PLUS (1 << 1)
#define DP_F_SPACE (1 << 2)
#define DP_F_NUM (1 << 3)
#define DP_F_ZERO (1 << 4)
#define DP_F_UP (1 << 5)
#define DP_F_UNSIGNED (1 << 6)
/* Conversion Flags */
#define DP_C_SHORT 1
#define DP_C_LONG 2
#define DP_C_LLONG 3
#define DP_C_LDOUBLE 4
#define char_to_int(p) (p - '0')
#define MAX(p,q) ((p >= q) ? p : q)
#define MIN(p,q) ((p <= q) ? p : q)
static int dopr (char *buffer, size_t maxlen, const char *format, va_list args)
{
char ch;
LLONG value;
LDOUBLE fvalue;
char *strvalue;
int min;
int max;
int state;
int flags;
int cflags;
int total;
size_t currlen;
state = DP_S_DEFAULT;
currlen = flags = cflags = min = 0;
max = -1;
ch = *format++;
total = 0;
while (state != DP_S_DONE)
{
if (ch == '\0')
state = DP_S_DONE;
switch(state)
{
case DP_S_DEFAULT:
if (ch == '%')
state = DP_S_FLAGS;
else
total += dopr_outch (buffer, &currlen, maxlen, ch);
ch = *format++;
break;
case DP_S_FLAGS:
switch (ch)
{
case '-':
flags |= DP_F_MINUS;
ch = *format++;
break;
case '+':
flags |= DP_F_PLUS;
ch = *format++;
break;
case ' ':
flags |= DP_F_SPACE;
ch = *format++;
break;
case '#':
flags |= DP_F_NUM;
ch = *format++;
break;
case '0':
flags |= DP_F_ZERO;
ch = *format++;
break;
default:
state = DP_S_MIN;
break;
}
break;
case DP_S_MIN:
if (isdigit((unsigned char)ch))
{
min = 10*min + char_to_int (ch);
ch = *format++;
}
else if (ch == '*')
{
min = va_arg (args, int);
ch = *format++;
state = DP_S_DOT;
}
else
state = DP_S_DOT;
break;
case DP_S_DOT:
if (ch == '.')
{
state = DP_S_MAX;
ch = *format++;
}
else
state = DP_S_MOD;
break;
case DP_S_MAX:
if (isdigit((unsigned char)ch))
{
if (max < 0)
max = 0;
max = 10*max + char_to_int (ch);
ch = *format++;
}
else if (ch == '*')
{
max = va_arg (args, int);
ch = *format++;
state = DP_S_MOD;
}
else
state = DP_S_MOD;
break;
case DP_S_MOD:
switch (ch)
{
case 'h':
cflags = DP_C_SHORT;
ch = *format++;
break;
case 'l':
cflags = DP_C_LONG;
ch = *format++;
break;
case 'L':
cflags = DP_C_LDOUBLE;
ch = *format++;
break;
default:
break;
}
if (cflags != DP_C_LONG)
state = DP_S_CONV;
else
state = DP_S_MOD_L;
break;
case DP_S_MOD_L:
switch (ch)
{
case 'l':
cflags = DP_C_LLONG;
ch = *format++;
break;
default:
break;
}
state = DP_S_CONV;
break;
case DP_S_CONV:
switch (ch)
{
case 'd':
case 'i':
if (cflags == DP_C_SHORT)
value = (short int) va_arg (args, int);
else if (cflags == DP_C_LONG)
value = va_arg (args, long int);
else if (cflags == DP_C_LLONG)
value = va_arg (args, LLONG);
else
value = va_arg (args, int);
total += fmtint (buffer, &currlen, maxlen, value, 10, min, max, flags);
break;
case 'o':
flags |= DP_F_UNSIGNED;
if (cflags == DP_C_SHORT)
value = (unsigned short int) va_arg (args, unsigned int);
else if (cflags == DP_C_LONG)
value = va_arg (args, unsigned long int);
else if (cflags == DP_C_LLONG)
value = va_arg (args, unsigned LLONG);
else
value = va_arg (args, unsigned int);
total += fmtint (buffer, &currlen, maxlen, value, 8, min, max, flags);
break;
case 'u':
flags |= DP_F_UNSIGNED;
if (cflags == DP_C_SHORT)
value = (unsigned short int) va_arg (args, unsigned int);
else if (cflags == DP_C_LONG)
value = va_arg (args, unsigned long int);
else if (cflags == DP_C_LLONG)
value = va_arg (args, unsigned LLONG);
else
value = va_arg (args, unsigned int);
total += fmtint (buffer, &currlen, maxlen, value, 10, min, max, flags);
break;
case 'X':
flags |= DP_F_UP;
case 'x':
flags |= DP_F_UNSIGNED;
if (cflags == DP_C_SHORT)
value = (unsigned short int) va_arg (args, unsigned int);
else if (cflags == DP_C_LONG)
value = va_arg (args, unsigned long int);
else if (cflags == DP_C_LLONG)
value = va_arg (args, unsigned LLONG);
else
value = va_arg (args, unsigned int);
total += fmtint (buffer, &currlen, maxlen, value, 16, min, max, flags);
break;
case 'f':
if (cflags == DP_C_LDOUBLE)
fvalue = va_arg (args, LDOUBLE);
else
fvalue = va_arg (args, double);
/* um, floating point? */
total += fmtfp (buffer, &currlen, maxlen, fvalue, min, max, flags);
break;
case 'E':
flags |= DP_F_UP;
case 'e':
if (cflags == DP_C_LDOUBLE)
fvalue = va_arg (args, LDOUBLE);
else
fvalue = va_arg (args, double);
break;
case 'G':
flags |= DP_F_UP;
case 'g':
if (cflags == DP_C_LDOUBLE)
fvalue = va_arg (args, LDOUBLE);
else
fvalue = va_arg (args, double);
break;
case 'c':
total += dopr_outch (buffer, &currlen, maxlen, va_arg (args, int));
break;
case 's':
strvalue = va_arg (args, char *);
total += fmtstr (buffer, &currlen, maxlen, strvalue, flags, min, max);
break;
case 'p':
strvalue = va_arg (args, void *);
total += fmtint (buffer, &currlen, maxlen, (long) strvalue, 16, min,
max, flags);
break;
case 'n':
if (cflags == DP_C_SHORT)
{
short int *num;
num = va_arg (args, short int *);
*num = currlen;
}
else if (cflags == DP_C_LONG)
{
long int *num;
num = va_arg (args, long int *);
*num = currlen;
}
else if (cflags == DP_C_LLONG)
{
LLONG *num;
num = va_arg (args, LLONG *);
*num = currlen;
}
else
{
int *num;
num = va_arg (args, int *);
*num = currlen;
}
break;
case '%':
total += dopr_outch (buffer, &currlen, maxlen, ch);
break;
case 'w':
/* not supported yet, treat as next char */
ch = *format++;
break;
default:
/* Unknown, skip */
break;
}
ch = *format++;
state = DP_S_DEFAULT;
flags = cflags = min = 0;
max = -1;
break;
case DP_S_DONE:
break;
default:
/* hmm? */
break; /* some picky compilers need this */
}
}
if (buffer != NULL)
{
if (currlen < maxlen - 1)
buffer[currlen] = '\0';
else
buffer[maxlen - 1] = '\0';
}
return total;
}
static int fmtstr (char *buffer, size_t *currlen, size_t maxlen,
char *value, int flags, int min, int max)
{
int padlen, strln; /* amount to pad */
int cnt = 0;
int total = 0;
char null[] = "<NULL>";
if (value == 0)
{
value = null;
}
for (strln = 0; value[strln]; ++strln); /* strlen */
if (max >= 0 && max < strln)
strln = max;
padlen = min - strln;
if (padlen < 0)
padlen = 0;
if (flags & DP_F_MINUS)
padlen = -padlen; /* Left Justify */
while (padlen > 0)
{
total += dopr_outch (buffer, currlen, maxlen, ' ');
--padlen;
}
while (*value && ((max < 0) || (cnt < max)))
{
total += dopr_outch (buffer, currlen, maxlen, *value++);
++cnt;
}
while (padlen < 0)
{
total += dopr_outch (buffer, currlen, maxlen, ' ');
++padlen;
}
return total;
}
/* Have to handle DP_F_NUM (ie 0x and 0 alternates) */
static int fmtint (char *buffer, size_t *currlen, size_t maxlen,
LLONG value, int base, int min, int max, int flags)
{
int signvalue = 0;
unsigned LLONG uvalue;
char convert[24];
unsigned int place = 0;
int spadlen = 0; /* amount to space pad */
int zpadlen = 0; /* amount to zero pad */
const char *digits;
int total = 0;
if (max < 0)
max = 0;
uvalue = value;
if(!(flags & DP_F_UNSIGNED))
{
if( value < 0 ) {
signvalue = '-';
uvalue = -value;
}
else
if (flags & DP_F_PLUS) /* Do a sign (+/i) */
signvalue = '+';
else
if (flags & DP_F_SPACE)
signvalue = ' ';
}
if (flags & DP_F_UP)
/* Should characters be upper case? */
digits = "0123456789ABCDEF";
else
digits = "0123456789abcdef";
do {
convert[place++] = digits[uvalue % (unsigned)base];
uvalue = (uvalue / (unsigned)base );
} while(uvalue && (place < sizeof (convert)));
if (place == sizeof (convert)) place--;
convert[place] = 0;
zpadlen = max - place;
spadlen = min - MAX ((unsigned int)max, place) - (signvalue ? 1 : 0);
if (zpadlen < 0) zpadlen = 0;
if (spadlen < 0) spadlen = 0;
if (flags & DP_F_ZERO)
{
zpadlen = MAX(zpadlen, spadlen);
spadlen = 0;
}
if (flags & DP_F_MINUS)
spadlen = -spadlen; /* Left Justifty */
#ifdef DEBUG_SNPRINTF
dprint (1, (debugfile, "zpad: %d, spad: %d, min: %d, max: %d, place: %d\n",
zpadlen, spadlen, min, max, place));
#endif
/* Spaces */
while (spadlen > 0)
{
total += dopr_outch (buffer, currlen, maxlen, ' ');
--spadlen;
}
/* Sign */
if (signvalue)
total += dopr_outch (buffer, currlen, maxlen, signvalue);
/* Zeros */
if (zpadlen > 0)
{
while (zpadlen > 0)
{
total += dopr_outch (buffer, currlen, maxlen, '0');
--zpadlen;
}
}
/* Digits */
while (place > 0)
total += dopr_outch (buffer, currlen, maxlen, convert[--place]);
/* Left Justified spaces */
while (spadlen < 0) {
total += dopr_outch (buffer, currlen, maxlen, ' ');
++spadlen;
}
return total;
}
static LDOUBLE abs_val (LDOUBLE value)
{
LDOUBLE result = value;
if (value < 0)
result = -value;
return result;
}
static LDOUBLE pow10 (int exp)
{
LDOUBLE result = 1;
while (exp)
{
result *= 10;
exp--;
}
return result;
}
static long round (LDOUBLE value)
{
long intpart;
intpart = value;
value = value - intpart;
if (value >= 0.5)
intpart++;
return intpart;
}
static int fmtfp (char *buffer, size_t *currlen, size_t maxlen,
LDOUBLE fvalue, int min, int max, int flags)
{
int signvalue = 0;
LDOUBLE ufvalue;
char iconvert[20];
char fconvert[20];
int iplace = 0;
int fplace = 0;
int padlen = 0; /* amount to pad */
int zpadlen = 0;
int caps = 0;
int total = 0;
LLONG intpart;
LLONG fracpart;
/*
* AIX manpage says the default is 0, but Solaris says the default
* is 6, and sprintf on AIX defaults to 6
*/
if (max < 0)
max = 6;
ufvalue = abs_val (fvalue);
if (fvalue < 0)
signvalue = '-';
else
if (flags & DP_F_PLUS) /* Do a sign (+/i) */
signvalue = '+';
else
if (flags & DP_F_SPACE)
signvalue = ' ';
#if 0
if (flags & DP_F_UP) caps = 1; /* Should characters be upper case? */
#endif
intpart = ufvalue;
/*
* Sorry, we only support 9 digits past the decimal because of our
* conversion method
*/
if (max > 9)
max = 9;
/* We "cheat" by converting the fractional part to integer by
* multiplying by a factor of 10
*/
fracpart = round ((pow10 (max)) * (ufvalue - intpart));
if (fracpart >= pow10 (max))
{
intpart++;
fracpart -= pow10 (max);
}
#ifdef DEBUG_SNPRINTF
dprint (1, (debugfile, "fmtfp: %f =? %d.%d\n", fvalue, intpart, fracpart));
#endif
/* Convert integer part */
do {
iconvert[iplace++] =
(caps? "0123456789ABCDEF":"0123456789abcdef")[intpart % 10];
intpart = (intpart / 10);
} while(intpart && (iplace < 20));
if (iplace == 20) iplace--;
iconvert[iplace] = 0;
/* Convert fractional part */
do {
fconvert[fplace++] =
(caps? "0123456789ABCDEF":"0123456789abcdef")[fracpart % 10];
fracpart = (fracpart / 10);
} while(fracpart && (fplace < 20));
if (fplace == 20) fplace--;
fconvert[fplace] = 0;
/* -1 for decimal point, another -1 if we are printing a sign */
padlen = min - iplace - max - 1 - ((signvalue) ? 1 : 0);
zpadlen = max - fplace;
if (zpadlen < 0)
zpadlen = 0;
if (padlen < 0)
padlen = 0;
if (flags & DP_F_MINUS)
padlen = -padlen; /* Left Justifty */
if ((flags & DP_F_ZERO) && (padlen > 0))
{
if (signvalue)
{
total += dopr_outch (buffer, currlen, maxlen, signvalue);
--padlen;
signvalue = 0;
}
while (padlen > 0)
{
total += dopr_outch (buffer, currlen, maxlen, '0');
--padlen;
}
}
while (padlen > 0)
{
total += dopr_outch (buffer, currlen, maxlen, ' ');
--padlen;
}
if (signvalue)
total += dopr_outch (buffer, currlen, maxlen, signvalue);
while (iplace > 0)
total += dopr_outch (buffer, currlen, maxlen, iconvert[--iplace]);
/*
* Decimal point. This should probably use locale to find the correct
* char to print out.
*/
if (max > 0)
{
total += dopr_outch (buffer, currlen, maxlen, '.');
while (fplace > 0)
total += dopr_outch (buffer, currlen, maxlen, fconvert[--fplace]);
}
while (zpadlen > 0)
{
total += dopr_outch (buffer, currlen, maxlen, '0');
--zpadlen;
}
while (padlen < 0)
{
total += dopr_outch (buffer, currlen, maxlen, ' ');
++padlen;
}
return total;
}
static int dopr_outch (char *buffer, size_t *currlen, size_t maxlen, char c)
{
if (*currlen + 1 < maxlen)
buffer[(*currlen)++] = c;
return 1;
}
int vsnprintf (char *str, size_t count, const char *fmt, va_list args)
{
if (str != NULL)
str[0] = 0;
return dopr(str, count, fmt, args);
}
/* VARARGS3 */
#ifdef HAVE_STDARGS
int snprintf (char *str,size_t count,const char *fmt,...)
#else
int snprintf (va_alist) va_dcl
#endif
{
#ifndef HAVE_STDARGS
char *str;
size_t count;
char *fmt;
#endif
VA_LOCAL_DECL;
int total;
VA_START (fmt);
VA_SHIFT (str, char *);
VA_SHIFT (count, size_t );
VA_SHIFT (fmt, char *);
total = vsnprintf(str, count, fmt, ap);
VA_END;
return total;
}
#ifdef TEST_SNPRINTF
#ifndef LONG_STRING
#define LONG_STRING 1024
#endif
int main (void)
{
char buf1[LONG_STRING];
char buf2[LONG_STRING];
char *fp_fmt[] = {
"%-1.5f",
"%1.5f",
"%123.9f",
"%10.5f",
"% 10.5f",
"%+22.9f",
"%+4.9f",
"%01.3f",
"%4f",
"%3.1f",
"%3.2f",
"%.0f",
"%.1f",
NULL
};
double fp_nums[] = { -1.5, 134.21, 91340.2, 341.1234, 0203.9, 0.96, 0.996,
0.9996, 1.996, 4.136, 0};
char *int_fmt[] = {
"%-1.5d",
"%1.5d",
"%123.9d",
"%5.5d",
"%10.5d",
"% 10.5d",
"%+22.33d",
"%01.3d",
"%4d",
NULL
};
long int_nums[] = { -1, 134, 91340, 341, 0203, 0};
int x, y;
int fail = 0;
int num = 0;
printf ("Testing snprintf format codes against system sprintf...\n");
for (x = 0; fp_fmt[x] != NULL ; x++)
for (y = 0; fp_nums[y] != 0 ; y++)
{
snprintf (buf1, sizeof (buf1), fp_fmt[x], fp_nums[y]);
sprintf (buf2, fp_fmt[x], fp_nums[y]);
if (strcmp (buf1, buf2))
{
printf("snprintf doesn't match Format: %s\n\tsnprintf = %s\n\tsprintf = %s\n",
fp_fmt[x], buf1, buf2);
fail++;
}
num++;
}
for (x = 0; int_fmt[x] != NULL ; x++)
for (y = 0; int_nums[y] != 0 ; y++)
{
snprintf (buf1, sizeof (buf1), int_fmt[x], int_nums[y]);
sprintf (buf2, int_fmt[x], int_nums[y]);
if (strcmp (buf1, buf2))
{
printf("snprintf doesn't match Format: %s\n\tsnprintf = %s\n\tsprintf = %s\n",
int_fmt[x], buf1, buf2);
fail++;
}
num++;
}
printf ("%d tests failed out of %d.\n", fail, num);
}
#endif /* SNPRINTF_TEST */
--
Russ Allbery (rra@stanford.edu) <http://www.eyrie.org/~eagle/>