/* $NetBSD: vsnprintf_ss.c,v 1.2.2.1 2007/05/07 19:49:09 pavel Exp $ */ /*- * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Chris Torek. * * 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. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS 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 REGENTS OR 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. */ #include #include #if defined(LIBC_SCCS) && !defined(lint) #if 0 static char sccsid[] = "@(#)vsnprintf.c 8.1 (Berkeley) 6/4/93"; #else __RCSID("$NetBSD: vsnprintf_ss.c,v 1.2.2.1 2007/05/07 19:49:09 pavel Exp $"); #endif #endif /* LIBC_SCCS and not lint */ #include "namespace.h" #include #include #include #include #include #include #include #include "reentrant.h" #include "extern.h" #include "local.h" #ifdef __weak_alias __weak_alias(vsnprintf_ss,_vsnprintf_ss) #endif /* * vsnprintf_ss: scaled down version of printf(3). * * this version based on vfprintf() from libc which was derived from * software contributed to Berkeley by Chris Torek. * */ /* * macros for converting digits to letters and vice versa */ #define to_digit(c) ((c) - '0') #define is_digit(c) ((unsigned)to_digit(c) <= 9) #define to_char(n) (char)((n) + '0') /* * flags used during conversion. */ #define ALT 0x001 /* alternate form */ #define HEXPREFIX 0x002 /* add 0x or 0X prefix */ #define LADJUST 0x004 /* left adjustment */ #define LONGDBL 0x008 /* long double; unimplemented */ #define LONGINT 0x010 /* long integer */ #define QUADINT 0x020 /* quad integer */ #define SHORTINT 0x040 /* short integer */ #define MAXINT 0x080 /* intmax_t */ #define PTRINT 0x100 /* intptr_t */ #define SIZEINT 0x200 /* size_t */ #define ZEROPAD 0x400 /* zero (as opposed to blank) pad */ #define FPT 0x800 /* Floating point number */ /* * To extend shorts properly, we need both signed and unsigned * argument extraction methods. */ #define SARG() \ ((INT64)(flags&MAXINT ? va_arg(ap, intmax_t) : \ flags&PTRINT ? va_arg(ap, intptr_t) : \ flags&SIZEINT ? va_arg(ap, ssize_t) : /* XXX */ \ flags&QUADINT ? va_arg(ap, quad_t) : \ flags&LONGINT ? va_arg(ap, long) : \ flags&SHORTINT ? (short)va_arg(ap, int) : \ va_arg(ap, int))) #define UARG() \ ((UINT64)(flags&MAXINT ? va_arg(ap, uintmax_t) : \ flags&PTRINT ? va_arg(ap, uintptr_t) : \ flags&SIZEINT ? va_arg(ap, size_t) : \ flags&QUADINT ? va_arg(ap, u_quad_t) : \ flags&LONGINT ? va_arg(ap, unsigned long) : \ flags&SHORTINT ? (u_short)va_arg(ap, int) : \ va_arg(ap, u_int))) #define PUTCHAR(C) do { \ if (sbuf < tailp) \ *sbuf++ = (C); \ } while (/*CONSTCOND*/0) int vsnprintf_ss(char *sbuf, size_t slen, const char *fmt0, va_list ap) { const char *fmt; /* format string */ int ch; /* character from fmt */ int n; /* handy integer (short term usage) */ char *cp; /* handy char pointer (short term usage) */ int flags; /* flags as above */ int ret; /* return value accumulator */ int width; /* width from format (%8d), or 0 */ int prec; /* precision from format (%.3d), or -1 */ char sign; /* sign prefix (' ', '+', '-', or \0) */ u_quad_t _uquad; /* integer arguments %[diouxX] */ enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */ int dprec; /* a copy of prec if [diouxX], 0 otherwise */ int realsz; /* field size expanded by dprec */ int size; /* size of converted field or string */ const char *xdigs; /* digits for [xX] conversion */ char bf[128]; /* space for %c, %[diouxX] */ char *tailp; /* tail pointer for snprintf */ static const char xdigs_lower[16] = "0123456789abcdef"; static const char xdigs_upper[16] = "0123456789ABCDEF"; _DIAGASSERT(n == 0 || sbuf != NULL); _DIAGASSERT(fmt != NULL); tailp = sbuf + slen; cp = NULL; /* XXX: shutup gcc */ size = 0; /* XXX: shutup gcc */ fmt = fmt0; ret = 0; xdigs = NULL; /* XXX: shut up gcc warning */ /* * Scan the format for conversions (`%' character). */ for (;;) { while (*fmt != '%' && *fmt) { ret++; PUTCHAR(*fmt++); } if (*fmt == 0) goto done; fmt++; /* skip over '%' */ flags = 0; dprec = 0; width = 0; prec = -1; sign = '\0'; rflag: ch = *fmt++; reswitch: switch (ch) { case ' ': /* * ``If the space and + flags both appear, the space * flag will be ignored.'' * -- ANSI X3J11 */ if (!sign) sign = ' '; goto rflag; case '#': flags |= ALT; goto rflag; case '*': /* * ``A negative field width argument is taken as a * - flag followed by a positive field width.'' * -- ANSI X3J11 * They don't exclude field widths read from args. */ if ((width = va_arg(ap, int)) >= 0) goto rflag; width = -width; /* FALLTHROUGH */ case '-': flags |= LADJUST; goto rflag; case '+': sign = '+'; goto rflag; case '.': if ((ch = *fmt++) == '*') { n = va_arg(ap, int); prec = n < 0 ? -1 : n; goto rflag; } n = 0; while (is_digit(ch)) { n = 10 * n + to_digit(ch); ch = *fmt++; } prec = n < 0 ? -1 : n; goto reswitch; case '0': /* * ``Note that 0 is taken as a flag, not as the * beginning of a field width.'' * -- ANSI X3J11 */ flags |= ZEROPAD; goto rflag; case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': n = 0; do { n = 10 * n + to_digit(ch); ch = *fmt++; } while (is_digit(ch)); width = n; goto reswitch; case 'h': flags |= SHORTINT; goto rflag; case 'j': flags |= MAXINT; goto rflag; case 'l': if (*fmt == 'l') { fmt++; flags |= QUADINT; } else { flags |= LONGINT; } goto rflag; case 'q': flags |= QUADINT; goto rflag; case 't': flags |= PTRINT; goto rflag; case 'z': flags |= SIZEINT; goto rflag; case 'c': *(cp = bf) = va_arg(ap, int); size = 1; sign = '\0'; break; case 'D': flags |= LONGINT; /*FALLTHROUGH*/ case 'd': case 'i': _uquad = SARG(); if ((quad_t)_uquad < 0) { _uquad = -_uquad; sign = '-'; } base = DEC; goto number; case 'n': if (flags & MAXINT) *va_arg(ap, intmax_t *) = ret; else if (flags & PTRINT) *va_arg(ap, intptr_t *) = ret; else if (flags & SIZEINT) *va_arg(ap, ssize_t *) = ret; else if (flags & QUADINT) *va_arg(ap, quad_t *) = ret; else if (flags & LONGINT) *va_arg(ap, long *) = (long)ret; else if (flags & SHORTINT) *va_arg(ap, short *) = (short)ret; else *va_arg(ap, int *) = ret; continue; /* no output */ case 'O': flags |= LONGINT; /*FALLTHROUGH*/ case 'o': _uquad = UARG(); base = OCT; goto nosign; case 'p': /* * ``The argument shall be a pointer to void. The * value of the pointer is converted to a sequence * of printable characters, in an implementation- * defined manner.'' * -- ANSI X3J11 */ /* NOSTRICT */ _uquad = (u_long)va_arg(ap, void *); base = HEX; xdigs = xdigs_lower; flags |= HEXPREFIX; ch = 'x'; goto nosign; case 's': if ((cp = va_arg(ap, char *)) == NULL) /*XXXUNCONST*/ cp = __UNCONST("(null)"); if (prec >= 0) { /* * can't use strlen; can only look for the * NUL in the first `prec' characters, and * strlen() will go further. */ char *p = memchr(cp, 0, (size_t)prec); if (p != NULL) { size = p - cp; if (size > prec) size = prec; } else size = prec; } else size = strlen(cp); sign = '\0'; break; case 'U': flags |= LONGINT; /*FALLTHROUGH*/ case 'u': _uquad = UARG(); base = DEC; goto nosign; case 'X': xdigs = xdigs_upper; goto hex; case 'x': xdigs = xdigs_lower; hex: _uquad = UARG(); base = HEX; /* leading 0x/X only if non-zero */ if (flags & ALT && _uquad != 0) flags |= HEXPREFIX; /* unsigned conversions */ nosign: sign = '\0'; /* * ``... diouXx conversions ... if a precision is * specified, the 0 flag will be ignored.'' * -- ANSI X3J11 */ number: if ((dprec = prec) >= 0) flags &= ~ZEROPAD; /* * ``The result of converting a zero value with an * explicit precision of zero is no characters.'' * -- ANSI X3J11 */ cp = bf + sizeof(bf); if (_uquad != 0 || prec != 0) { /* * Unsigned mod is hard, and unsigned mod * by a constant is easier than that by * a variable; hence this switch. */ switch (base) { case OCT: do { *--cp = to_char(_uquad & 7); _uquad >>= 3; } while (_uquad); /* handle octal leading 0 */ if (flags & ALT && *cp != '0') *--cp = '0'; break; case DEC: /* many numbers are 1 digit */ while (_uquad >= 10) { *--cp = to_char(_uquad % 10); _uquad /= 10; } *--cp = to_char(_uquad); break; case HEX: do { *--cp = xdigs[(size_t)_uquad & 15]; _uquad >>= 4; } while (_uquad); break; default: /*XXXUNCONST*/ cp = __UNCONST("bug bad base"); size = strlen(cp); goto skipsize; } } size = bf + sizeof(bf) - cp; skipsize: break; default: /* "%?" prints ?, unless ? is NUL */ if (ch == '\0') goto done; /* pretend it was %c with argument ch */ cp = bf; *cp = ch; size = 1; sign = '\0'; break; } /* * All reasonable formats wind up here. At this point, `cp' * points to a string which (if not flags&LADJUST) should be * padded out to `width' places. If flags&ZEROPAD, it should * first be prefixed by any sign or other prefix; otherwise, * it should be blank padded before the prefix is emitted. * After any left-hand padding and prefixing, emit zeroes * required by a decimal [diouxX] precision, then print the * string proper, then emit zeroes required by any leftover * floating precision; finally, if LADJUST, pad with blanks. * * Compute actual size, so we know how much to pad. * size excludes decimal prec; realsz includes it. */ realsz = dprec > size ? dprec : size; if (sign) realsz++; else if (flags & HEXPREFIX) realsz+= 2; /* adjust ret */ ret += width > realsz ? width : realsz; /* right-adjusting blank padding */ if ((flags & (LADJUST|ZEROPAD)) == 0) { n = width - realsz; while (n-- > 0) PUTCHAR(' '); } /* prefix */ if (sign) { PUTCHAR(sign); } else if (flags & HEXPREFIX) { PUTCHAR('0'); PUTCHAR(ch); } /* right-adjusting zero padding */ if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) { n = width - realsz; while (n-- > 0) PUTCHAR('0'); } /* leading zeroes from decimal precision */ n = dprec - size; while (n-- > 0) PUTCHAR('0'); /* the string or number proper */ while (size--) PUTCHAR(*cp++); /* left-adjusting padding (always blank) */ if (flags & LADJUST) { n = width - realsz; while (n-- > 0) PUTCHAR(' '); } } done: if (sbuf == tailp) sbuf[-1] = '\0'; else *sbuf = '\0'; return (ret); /* NOTREACHED */ }