snprintf.c

Rsync 3.0.5 source code

/*
 * NOTE: If you change this file, please merge it into rsync, samba, etc.
 */

/*
 * Copyright Patrick Powell 1995
 * This code is based on code written by Patrick Powell ([e-mail])
 * 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 <[e-mail]> 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 <[e-mail]> 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 <[e-mail]> 01/27/98 for mutt 0.89i
 *    The PGP code was using unsigned hexadecimal formats. 
 *    Unfortunately, unsigned formats simply didn't work.
 *
 *  Michael Elkins <[e-mail]> 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 ([e-mail]) Oct 1998
 *    fixed handling of %.0f
 *    added test for HAVE_LONG_DOUBLE
 *
 * [e-mail], [e-mail], April 2001
 *    got rid of fcvt code (twas buggy and made testing harder)
 *    added C99 semantics
 *
 * date: 2002/12/19 19:56:31;  author: herb;  state: Exp;  lines: +2 -0
 * actually print args for %g and %e
 * 
 * date: 2002/06/03 13:37:52;  author: jmcd;  state: Exp;  lines: +8 -0
 * Since includes.h isn't included here, VA_COPY has to be defined here.  I don't
 * see any include file that is guaranteed to be here, so I'm defining it
 * locally.  Fixes AIX and Solaris builds.
 * 
 * date: 2002/06/03 03:07:24;  author: tridge;  state: Exp;  lines: +5 -13
 * put the ifdef for HAVE_VA_COPY in one place rather than in lots of
 * functions
 * 
 * date: 2002/05/17 14:51:22;  author: jmcd;  state: Exp;  lines: +21 -4
 * Fix usage of va_list passed as an arg.  Use __va_copy before using it
 * when it exists.
 * 
 * date: 2002/04/16 22:38:04;  author: idra;  state: Exp;  lines: +20 -14
 * Fix incorrect zpadlen handling in fmtfp.
 * Thanks to Ollie Oldham <[e-mail]> for spotting it.
 * few mods to make it easier to compile the tests.
 * addedd the "Ollie" test to the floating point ones.
 *
 * Martin Pool ([e-mail]) April 2003
 *    Remove NO_CONFIG_H so that the test case can be built within a source
 *    tree with less trouble.
 *    Remove unnecessary SAFE_FREE() definition.
 *
 * Martin Pool ([e-mail]) May 2003
 *    Put in a prototype for dummy_snprintf() to quiet compiler warnings.
 *
 *    Move #endif to make sure VA_COPY, LDOUBLE, etc are defined even
 *    if the C library has some snprintf functions already.
 **************************************************************/

#ifndef NO_CONFIG_H
#include "config.h"
#else
#define NULL 0
#endif 

#ifdef TEST_SNPRINTF /* need math library headers for testing */

/* In test mode, we pretend that this system doesn't have any snprintf
 * functions, regardless of what config.h says. */
#  undef HAVE_SNPRINTF
#  undef HAVE_VSNPRINTF
#  undef HAVE_C99_VSNPRINTF
#  undef HAVE_ASPRINTF
#  undef HAVE_VASPRINTF
#  include <math.h>
#endif /* TEST_SNPRINTF */

#ifdef HAVE_STRING_H
#include <string.h>
#endif

#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#ifdef HAVE_CTYPE_H
#include <ctype.h>
#endif
#include <sys/types.h>
#include <stdarg.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif

#if defined(HAVE_SNPRINTF) && defined(HAVE_VSNPRINTF) && defined(HAVE_C99_VSNPRINTF)
/* only include stdio.h if we are not re-defining snprintf or vsnprintf */
#include <stdio.h>
 /* make the compiler happy with an empty file */
 void dummy_snprintf(void);
 void dummy_snprintf(void) {} 
#endif /* HAVE_SNPRINTF, etc */

#ifdef HAVE_LONG_DOUBLE
#define LDOUBLE long double
#else
#define LDOUBLE double
#endif

#if SIZEOF_LONG_LONG
#define LLONG long long
#else
#define LLONG long
#endif

#ifndef VA_COPY
#if defined HAVE_VA_COPY || defined va_copy
#define VA_COPY(dest, src) va_copy(dest, src)
#else
#ifdef HAVE___VA_COPY
#define VA_COPY(dest, src) __va_copy(dest, src)
#else
#define VA_COPY(dest, src) (dest) = (src)
#endif
#endif

/*
 * 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_CONV    6
#define DP_S_DONE    7

/* 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_LDOUBLE 3
#define DP_C_LLONG   4

#define char_to_int(p) ((p)- '0')
#ifndef MAX
#define MAX(p,q) (((p) >= (q)) ? (p) : (q))
#endif

/* yes this really must be a ||. Don't muck with this (tridge) */
#if !defined(HAVE_VSNPRINTF) || !defined(HAVE_C99_VSNPRINTF)

static size_t dopr(char *buffer, size_t maxlen, const char *format, 
		   va_list args_in);
static void fmtstr(char *buffer, size_t *currlen, size_t maxlen,
		    char *value, int flags, int min, int max);
static void fmtint(char *buffer, size_t *currlen, size_t maxlen,
		    long value, int base, int min, int max, int flags);
static void fmtfp(char *buffer, size_t *currlen, size_t maxlen,
		   LDOUBLE fvalue, int min, int max, int flags);
static void dopr_outch(char *buffer, size_t *currlen, size_t maxlen, char c);

static size_t dopr(char *buffer, size_t maxlen, const char *format, va_list args_in)
{
	char ch;
	LLONG value;
	LDOUBLE fvalue;
	char *strvalue;
	int min;
	int max;
	int state;
	int flags;
	int cflags;
	size_t currlen;
	va_list args;

	VA_COPY(args, args_in);
	
	state = DP_S_DEFAULT;
	currlen = flags = cflags = min = 0;
	max = -1;
	ch = *format++;
	
	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 
				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++;
				if (ch == 'l') {	/* It's a long long */
					cflags = DP_C_LLONG;
					ch = *format++;
				}
				break;
			case 'L':
				cflags = DP_C_LDOUBLE;
				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 = 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);
				fmtint (buffer, &currlen, maxlen, value, 10, min, max, flags);
				break;
			case 'o':
				flags |= DP_F_UNSIGNED;
				if (cflags == DP_C_SHORT)
					value = va_arg (args, unsigned int);
				else if (cflags == DP_C_LONG)
					value = (long)va_arg (args, unsigned long int);
				else if (cflags == DP_C_LLONG)
					value = (long)va_arg (args, unsigned LLONG);
				else
					value = (long)va_arg (args, unsigned int);
				fmtint (buffer, &currlen, maxlen, value, 8, min, max, flags);
				break;
			case 'u':
				flags |= DP_F_UNSIGNED;
				if (cflags == DP_C_SHORT)
					value = va_arg (args, unsigned int);
				else if (cflags == DP_C_LONG)
					value = (long)va_arg (args, unsigned long int);
				else if (cflags == DP_C_LLONG)
					value = (LLONG)va_arg (args, unsigned LLONG);
				else
					value = (long)va_arg (args, unsigned int);
				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 = va_arg (args, unsigned int);
				else if (cflags == DP_C_LONG)
					value = (long)va_arg (args, unsigned long int);
				else if (cflags == DP_C_LLONG)
					value = (LLONG)va_arg (args, unsigned LLONG);
				else
					value = (long)va_arg (args, unsigned int);
				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? */
				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);
				fmtfp (buffer, &currlen, maxlen, fvalue, min, max, flags);
				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);
				fmtfp (buffer, &currlen, maxlen, fvalue, min, max, flags);
				break;
			case 'c':
				dopr_outch (buffer, &currlen, maxlen, va_arg (args, int));
				break;
			case 's':
				strvalue = va_arg (args, char *);
				if (!strvalue) strvalue = "(NULL)";
				if (max == -1) {
					max = strlen(strvalue);
				}
				if (min > 0 && max >= 0 && min > max) max = min;
				fmtstr (buffer, &currlen, maxlen, strvalue, flags, min, max);
				break;
			case 'p':
				strvalue = va_arg (args, void *);
				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 = (long int)currlen;
				} else if (cflags == DP_C_LLONG) {
					LLONG *num;
					num = va_arg (args, LLONG *);
					*num = (LLONG)currlen;
				} else {
					int *num;
					num = va_arg (args, int *);
					*num = currlen;
				}
				break;
			case '%':
				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 (maxlen != 0) {
		if (currlen < maxlen - 1) 
			buffer[currlen] = '\0';
		else if (maxlen > 0) 
			buffer[maxlen - 1] = '\0';
	}
	
	return currlen;
}

static void 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;

#ifdef DEBUG_SNPRINTF
	printf("fmtstr min=%d max=%d s=[%s]\n", min, max, value);
#endif
	if (value == 0) {
		value = "<NULL>";
	}

	for (strln = 0; value[strln]; ++strln); /* strlen */
	padlen = min - strln;
	if (padlen < 0) 
		padlen = 0;
	if (flags & DP_F_MINUS) 
		padlen = -padlen; /* Left Justify */
	
	while ((padlen > 0) && (cnt < max)) {
		dopr_outch (buffer, currlen, maxlen, ' ');
		--padlen;
		++cnt;
	}
	while (*value && (cnt < max)) {
		dopr_outch (buffer, currlen, maxlen, *value++);
		++cnt;
	}
	while ((padlen < 0) && (cnt < max)) {
		dopr_outch (buffer, currlen, maxlen, ' ');
		++padlen;
		++cnt;
	}
}

/* Have to handle DP_F_NUM (ie 0x and 0 alternates) */

static void fmtint(char *buffer, size_t *currlen, size_t maxlen,
		    long value, int base, int min, int max, int flags)
{
	int signvalue = 0;
	unsigned long uvalue;