/*

 * This version of snprintf() and vsnprintf() is based on Sprint from

 * SIO by Panagiotis Tsirigotis, as included with xidentd-2.2.1.

 *

 * The modifications were made by The XFree86 Project, Inc and are

 * Copyright 1999 by The XFree86 Project, Inc.  These modifications

 * consist of removing the support for writing to file streams,

 * renaming some functions, ansification, and making some adjustments

 * to achieve the semantics for snprintf and vsnprintf() as described

 * in the relevant man page for FreeBSD 2.2.8.

 *

 *

 * The original version carries the following notice:

 *

 * (c) Copyright 1992, 1993 by Panagiotis Tsirigotis

 *

 * The author (Panagiotis Tsirigotis) grants permission to use, copy,

 * and distribute this software and its documentation for any purpose

 * and without fee, provided that a) the above copyright notice extant in

 * files in this distribution is not removed from files included in any

 * redistribution, and b) this file is also included in any redistribution.

 *

 * Modifications to this software may be distributed, either by distributing

 * the modified software or by distributing patches to the original software,

 * under the following additional terms:

 *

 * 1. The version number will be modified as follows:

 *      a. The first 3 components of the version number

 *         (i.e. <number>.<number>.<number>) will remain unchanged.

 *      b. A new component will be appended to the version number to indicate

 *         the modification level. The form of this component is up to the

 *         author of the modifications.

 *

 * 2. The author of the modifications will include his/her name by appending

 *    it along with the new version number to this file and will be

 *    responsible for any wrong behavior of the modified software.

 *

 * The author makes no representations about the suitability of this

 * software for any purpose.  It is provided "as is" without any express

 * or implied warranty.

 *

 * Changes and modifications for: 

 *

 * xinetd Version 2.1.4-bsdi

 * xinetd Version 2.1.4-freebsd

 * xinetd Version 2.1.4-linux

 *

 * are      

 *

 * (c) Copyright 1995 by Charles Murcko

 * All Rights Reserved

 */

/* $XFree86: xc/lib/misc/snprintf.c,v 3.1 1999/04/28 15:04:51 dawes Exp $ */

/*

 * Assumption: systems that don't have snprintf and vsnprintf do have

 * ecvt, fcvt and gcvt.

 */

/* From: Id: sprint.c,v 1.5 1995/09/10 18:35:09 chuck Exp */

#ifdef HAVE_CONFIG_H

# include <config.h>

#endif

#ifndef HAVE_STDARG_H

#error Need stdarg here!

#endif

#include <ctype.h>

#include <stdlib.h>

#include <stdarg.h>

#include <string.h>

#include <sys/types.h>

#ifndef SCOPE

#define SCOPE					/**/

#endif

#ifndef WIDE_INT

#define WIDE_INT				long

#endif

typedef WIDE_INT wide_int;

typedef unsigned WIDE_INT u_wide_int;

typedef int bool_int;

#ifndef FALSE

#define FALSE					0

#define TRUE					1

#endif

#define NUL					'\0'

#define S_NULL					"(null)"

#define S_NULL_LEN				6

#define FLOAT_DIGITS				6

#define EXPONENT_LENGTH				10

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

/*

 * 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

/*

 * The INS_CHAR macro inserts a character in the buffer.

 * 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

 * While using this macro, note that the nextb pointer is NOT updated.

 *

 * Excess characters are discarded if the string overflows.

 *

 * NOTE: Evaluation of the c argument should not have any side-effects

 */

#define INS_CHAR( c, sp, bep, cc )					\

	{								\

	    if ( sp < bep )						\

		*sp++ = c ;						\

	    cc++ ;							\

	}

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

#define STR_TO_DEC( str, num )						\

	num = NUM( *str++ ) ;						\

	while ( 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

static char *conv_10(wide_int num, bool_int is_unsigned,

			bool_int * is_negative, char *buf_end, int *len);

SCOPE int vsnprintf(char *str, size_t size, const char *fmt, va_list ap);

/*

 * snprintf is based on SIO's Sprint.

 *

 * Sprint is the equivalent of printf for SIO.

 * It returns the # of chars written

 * Assumptions:

 *     - all floating point arguments are passed as doubles

 */

SCOPE int 

snprintf(char *str, size_t size, const char *fmt, ...)

{

    int cc;

    va_list ap;

    va_start(ap, fmt);

    cc = vsnprintf(str, size, fmt, ap);

    va_end(ap);

    return cc;

}

/*

 * 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).  Always add decimal point if add_dp is YES.

 */

static char *

conv_fp(char format, double num, boolean_e add_dp, int precision,

	bool_int *is_negative, char buf[], int *len)

{

    char *s = buf;

    char *p;

    int decimal_point;

    if (format == 'f')

	p = fcvt(num, precision, &decimal_point, is_negative);

    else			       /* either e or E format */

	p = ecvt(num, precision + 1, &decimal_point, is_negative);

    /*

     * Check for Infinity and NaN

     */

    if (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(u_wide_int num, int nbits, char format, char *buf_end, int *len)

{

    int mask = (1 << nbits) - 1;

    char *p = buf_end;

    static char low_digits[] = "0123456789abcdef";

    static char upper_digits[] = "0123456789ABCDEF";

    char *digits = (format == 'X') ? upper_digits : low_digits;

    do {

	*--p = digits[num & mask];

	num >>= nbits;

    }

    while (num);

    *len = buf_end - p;

    return (p);

}

/*

 * 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(wide_int num, bool_int is_unsigned, bool_int *is_negative,

	char *buf_end, int *len)

{

    char *p = buf_end;

    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 = magnitude - new_magnitude * 10 + '0';

	magnitude = new_magnitude;

    }

    while (magnitude);

    *len = buf_end - p;

    return (p);

}

/*

 * Do format conversion.

 */

SCOPE int 

vsnprintf(char *str, size_t size, const char *fmt, va_list ap)

{

    char *sp;

    char *bep;

    int cc = 0;

    int i;

    char *s;

    char *q;

    int s_len;

    int min_width;

    int precision;

    enum {

	LEFT, RIGHT

    } adjust;

    char pad_char;

    char prefix_char;

    double fp_num;

    wide_int i_num;

    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;

    if (size == 0)

	return 0;

    sp = str;

    bep = str + size - 1;

    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 (isascii(*fmt) && !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 (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 (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

		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 'd':

	    case 'i':

	    case 'u':

		if (is_long)

		    i_num = va_arg(ap, wide_int);

		else

		    i_num = (wide_int) va_arg(ap, int);

		s = conv_10(i_num, (*fmt) == 'u', &is_negative,

		    &num_buf[NUM_BUF_SIZE], &s_len);

		FIX_PRECISION(adjust_precision, precision, s, s_len);

		if (*fmt != 'u') {

		    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);

		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 = gcvt(va_arg(ap, double), precision, &num_buf[1]);

		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++] = '.';

		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;

		/*

		 * 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(void *) <= sizeof(u_wide_int))

		        s = conv_p2(ui_num, 4, 'x',

			&num_buf[NUM_BUF_SIZE], &s_len);

		else {

		    s = "%p";

		    s_len = 2;

		}

		pad_char = ' ';

		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 __sio_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 = 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++;

    }

    if (cc < size)

	str[cc] = NUL;

    else

	str[size - 1] = NUL;

    return cc;

}