/* * $Id: snprintf.c,v 1.18 2001/01/07 10:57:14 hno Exp $ */ /* ==================================================================== * Copyright (c) 1995-1997 The Apache Group. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. 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. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the Apache Group * for use in the Apache HTTP server project (http://www.apache.org/)." * * 4. The names "Apache Server" and "Apache Group" must not be used to * endorse or promote products derived from this software without * prior written permission. * * 5. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the Apache Group * for use in the Apache HTTP server project (http://www.apache.org/)." * * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY * EXPRESSED 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 APACHE GROUP OR * ITS 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. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Group and was originally based * on public domain software written at the National Center for * Supercomputing Applications, University of Illinois, Urbana-Champaign. * For more information on the Apache Group and the Apache HTTP server * project, please see . * * This code is based on, and used with the permission of, the * SIO stdio-replacement strx_* functions by Panos Tsirigotis * for xinetd. */ #include "config.h" #if !HAVE_SNPRINTF || !HAVE_VSNPRINTF #include #include #include #include #include #include #include #include #ifdef HAVE_CVT #define ap_ecvt ecvt #define ap_fcvt fcvt #define ap_gcvt gcvt #else /* * cvt.c - IEEE floating point formatting routines for FreeBSD * from GNU libc-4.6.27 */ /* * ap_ecvt converts to decimal * the number of digits is specified by ndigit * decpt is set to the position of the decimal point * sign is set to 0 for positive, 1 for negative */ #define NDIG 80 static char * ap_cvt(double arg, int ndigits, int *decpt, int *sign, int eflag) { register int r2; double fi, fj; register char *p, *p1; static char buf[NDIG]; if (ndigits >= NDIG - 1) ndigits = NDIG - 2; r2 = 0; *sign = 0; p = &buf[0]; if (arg < 0) { *sign = 1; arg = -arg; } arg = modf(arg, &fi); p1 = &buf[NDIG]; /* * Do integer part */ if (fi != 0) { p1 = &buf[NDIG]; while (fi != 0) { fj = modf(fi / 10, &fi); *--p1 = (int) ((fj + .03) * 10) + '0'; r2++; } while (p1 < &buf[NDIG]) *p++ = *p1++; } else if (arg > 0) { while ((fj = arg * 10) < 1) { arg = fj; r2--; } } p1 = &buf[ndigits]; if (eflag == 0) p1 += r2; *decpt = r2; if (p1 < &buf[0]) { buf[0] = '\0'; return (buf); } while (p <= p1 && p < &buf[NDIG]) { arg *= 10; arg = modf(arg, &fj); *p++ = (int) fj + '0'; } if (p1 >= &buf[NDIG]) { buf[NDIG - 1] = '\0'; return (buf); } p = p1; *p1 += 5; while (*p1 > '9') { *p1 = '0'; if (p1 > buf) ++ * --p1; else { *p1 = '1'; (*decpt)++; if (eflag == 0) { if (p > buf) *p = '0'; p++; } } } *p = '\0'; return (buf); } static char * ap_ecvt(double arg, int ndigits, int *decpt, int *sign) { return (ap_cvt(arg, ndigits, decpt, sign, 1)); } static char * ap_fcvt(double arg, int ndigits, int *decpt, int *sign) { return (ap_cvt(arg, ndigits, decpt, sign, 0)); } /* * ap_gcvt - Floating output conversion to * minimal length string */ static char * ap_gcvt(double number, int ndigit, char *buf) { int sign, decpt; register char *p1, *p2; register int i; p1 = ap_ecvt(number, ndigit, &decpt, &sign); p2 = buf; if (sign) *p2++ = '-'; for (i = ndigit - 1; i > 0 && p1[i] == '0'; i--) ndigit--; if ((decpt >= 0 && decpt - ndigit > 4) || (decpt < 0 && decpt < -3)) { /* use E-style */ decpt--; *p2++ = *p1++; *p2++ = '.'; for (i = 1; i < ndigit; i++) *p2++ = *p1++; *p2++ = 'e'; if (decpt < 0) { decpt = -decpt; *p2++ = '-'; } else *p2++ = '+'; if (decpt / 100 > 0) *p2++ = decpt / 100 + '0'; if (decpt / 10 > 0) *p2++ = (decpt % 100) / 10 + '0'; *p2++ = decpt % 10 + '0'; } else { if (decpt <= 0) { if (*p1 != '0') *p2++ = '.'; while (decpt < 0) { decpt++; *p2++ = '0'; } } for (i = 1; i <= ndigit; i++) { *p2++ = *p1++; if (i == decpt) *p2++ = '.'; } if (ndigit < decpt) { while (ndigit++ < decpt) *p2++ = '0'; *p2++ = '.'; } } if (p2[-1] == '.') p2--; *p2 = '\0'; return (buf); } #endif /* HAVE_CVT */ typedef enum { NO = 0, YES = 1 } boolean_e; #define FALSE 0 #define TRUE 1 #define NUL '\0' #define INT_NULL ((int *)0) #define WIDE_INT long typedef WIDE_INT wide_int; typedef unsigned WIDE_INT u_wide_int; typedef int bool_int; #define S_NULL "(null)" #define S_NULL_LEN 6 #define FLOAT_DIGITS 6 #define EXPONENT_LENGTH 10 /* * 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 /* * Descriptor for buffer area */ struct buf_area { char *buf_end; char *nextb; /* pointer to next byte to read/write */ }; typedef struct buf_area buffy; /* * The INS_CHAR macro inserts a character in the buffer and writes * the buffer back to disk if necessary * 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+1 * While using this macro, note that the nextb pointer is NOT updated. * * 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 ( xisdigit( *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 /* * 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(register wide_int num, register bool_int is_unsigned, register bool_int * is_negative, char *buf_end, register int *len) { register char *p = buf_end; register 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 = (char) (magnitude - new_magnitude * 10 + '0'); magnitude = new_magnitude; } while (magnitude); *len = buf_end - p; return (p); } /* * 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). */ static char * conv_fp(register char format, register double num, boolean_e add_dp, int precision, bool_int * is_negative, char *buf, int *len) { register char *s = buf; register char *p; int decimal_point; if (format == 'f') p = ap_fcvt(num, precision, &decimal_point, is_negative); else /* either e or E format */ p = ap_ecvt(num, precision + 1, &decimal_point, is_negative); /* * Check for Infinity and NaN */ if (xisalpha(*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(register u_wide_int num, register int nbits, char format, char *buf_end, register int *len) { register int mask = (1 << nbits) - 1; register char *p = buf_end; static char low_digits[] = "0123456789abcdef"; static char upper_digits[] = "0123456789ABCDEF"; register char *digits = (format == 'X') ? upper_digits : low_digits; do { *--p = digits[num & mask]; num >>= nbits; } while (num); *len = buf_end - p; return (p); } /* * Do format conversion placing the output in buffer */ static int format_converter(register buffy * odp, const char *fmt, va_list ap) { register char *sp; register char *bep; register int cc = 0; register int i; register char *s = NULL; char *q; int s_len; register int min_width = 0; int precision = 0; enum { LEFT, RIGHT } adjust; char pad_char; char prefix_char; double fp_num; wide_int i_num = (wide_int) 0; u_wide_int ui_num; char num_buf[NUM_BUF_SIZE]; char char_buf[2]; /* for printing %% and % */ /* * 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; sp = odp->nextb; bep = odp->buf_end; 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 (xisascii(*fmt) && !xislower(*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 (xisdigit(*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 (xisdigit(*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 'u': if (is_long) i_num = va_arg(ap, u_wide_int); else i_num = (wide_int) va_arg(ap, unsigned int); /* * The rest also applies to other integer formats, so fall * into that case. */ case 'd': case 'i': /* * Get the arg if we haven't already. */ if ((*fmt) != '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 = ap_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; /* * Always extract the argument as a "char *" pointer. We * should be using "void *" but there are still machines * that don't understand it. * 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, char *); if (sizeof(char *) <= 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 % to help the user identify what * option is not understood. * This is also useful in case the user wants to pass * the output of format_converter to another function * that understands some other % (like syslog). * Note that we can't point s inside fmt because the * unknown 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++; } odp->nextb = sp; return (cc); } /* * This is the general purpose conversion function. * Must be called with len >= 0, but we cannot assert() that * because size_t is unsigned on some platforms */ static void strx_printv(int *ccp, char *buf, size_t len, const char *format, va_list ap) { buffy od; int cc; #if OLD_CODE /* * First initialize the descriptor * Notice that if no length is given, we initialize buf_end to the * highest possible address. */ od.buf_end = len ? &buf[len] : (char *) ~0; #else od.buf_end = &buf[len]; #endif od.nextb = buf; /* * Do the conversion */ cc = format_converter(&od, format, ap); if (len == 0 || od.nextb <= od.buf_end) *(od.nextb) = '\0'; if (ccp) *ccp = cc; } #endif #if !HAVE_SNPRINTF /* * if len == 0, silently return */ int snprintf(char *buf, size_t len, const char *format,...) { int cc = 0; va_list ap; va_start(ap, format); if (len > 0) strx_printv(&cc, buf, (len - 1), format, ap); va_end(ap); return (cc); } #endif #if !HAVE_VSNPRINTF /* * if len == 0, silently return */ int vsnprintf(char *buf, size_t len, const char *format, va_list ap) { int cc = 0; if (len > 0) strx_printv(&cc, buf, (len - 1), format, ap); return (cc); } #endif