bsd-snprintf.c

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/*
 * 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.
 *
 *  Ben Lindstrom <[e-mail]> 09/27/00 for OpenSSH
 *    Welcome to the world of %lld and %qd support.  With other
 *    long long support.  This is needed for sftp-server to work
 *    right.
 *
 *  Ben Lindstrom <[e-mail]> 02/12/01 for OpenSSH
 *    Removed all hint of VARARGS stuff and banished it to the void,
 *    and did a bit of KNF style work to make things a bit more
 *    acceptable.  Consider stealing from mutt or enlightenment.
 **************************************************************/

#include "includes.h"

RCSID("$Id: bsd-snprintf.c,v 1.9 2004/09/23 11:35:09 dtucker Exp $");

#if defined(BROKEN_SNPRINTF)		/* For those with broken snprintf() */
# undef HAVE_SNPRINTF
# undef HAVE_VSNPRINTF
#endif

#if !defined(HAVE_SNPRINTF) || !defined(HAVE_VSNPRINTF)

static void 
dopr(char *buffer, size_t maxlen, const char *format, va_list args);

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, long double fvalue, 
    int min, int max, int flags);

static void
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_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_LONG_LONG 4

#define char_to_int(p) (p - '0')
#define abs_val(p) (p < 0 ? -p : p)


static void 
dopr(char *buffer, size_t maxlen, const char *format, va_list args)
{
	char *strvalue, ch;
	long value;
	long double fvalue;
	int min = 0, max = -1, state = DP_S_DEFAULT, flags = 0, cflags = 0;
	size_t currlen = 0;
  
	ch = *format++;

	while (state != DP_S_DONE) {
		if ((ch == '\0') || (currlen >= maxlen)) 
			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') {
					cflags = DP_C_LONG_LONG;
					ch = *format++;
				}
				break;
			case 'q':
				cflags = DP_C_LONG_LONG;
				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_LONG_LONG)
					value = va_arg (args, long long);
				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 = va_arg(args, unsigned long int);
				else if (cflags == DP_C_LONG_LONG)
					value = va_arg(args, unsigned long long);
				else
					value = 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 = va_arg(args, unsigned long int);
				else if (cflags == DP_C_LONG_LONG)
					value = va_arg(args, unsigned long long);
				else
					value = 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 = va_arg(args, unsigned long int);
				else if (cflags == DP_C_LONG_LONG)
					value = va_arg(args, unsigned long long);
				else
					value = 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, long double);
				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, long double);
				else
					fvalue = va_arg(args, double);
				break;
			case 'G':
				flags |= DP_F_UP;
			case 'g':
				if (cflags == DP_C_LDOUBLE)
					fvalue = va_arg(args, long double);
				else
					fvalue = va_arg(args, double);
				break;
			case 'c':
				dopr_outch(buffer, &currlen, maxlen, va_arg(args, int));
				break;
			case 's':
				strvalue = va_arg(args, char *);
				if (max < 0) 
					max = maxlen; /* ie, no max */
				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 = currlen;
				} else if (cflags == DP_C_LONG_LONG) {