/* $NetBSD: snprintf.c,v 1.3 2004/08/23 03:32:12 jlam Exp $ */ /* * Copyright Patrick Powell 1995 * This code is based on code written by Patrick Powell (papowell@astart.com) * 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 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 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 01/27/98 for mutt 0.89i * The PGP code was using unsigned hexadecimal formats. * Unfortunately, unsigned formats simply didn't work. * * Michael Elkins 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 (tridge@samba.org) Oct 1998 * fixed handling of %.0f * added test for HAVE_LONG_DOUBLE * * Luke Mewburn , Thu Sep 30 23:28:21 EST 1999 * cleaned up formatting, autoconf tests * added long long support * **************************************************************/ #include #if HAVE_STDARG_H #include #endif #if HAVE_LONG_DOUBLE #define LDOUBLE long double #else #define LDOUBLE double #endif #if HAVE_LONG_LONG #define LLONG long long #else #define LLONG long #endif static void dopr(char *buffer, size_t maxlen, size_t *retlen, const char *format, va_list args); static void fmtstr(char *buffer, size_t * currlen, size_t maxlen, char *value, int min, int max, int flags); static void fmtint(char *buffer, size_t * currlen, size_t maxlen, LLONG 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, int 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_LLONG 4 #define char_to_int(p) (p - '0') static void dopr(char *buffer, size_t maxlen, size_t *retlen, const char *format, va_list args) { char ch; LLONG value; LDOUBLE fvalue; char *strvalue; int min; int max; int state; int flags; int cflags; size_t currlen; state = DP_S_DEFAULT; flags = currlen = cflags = min = 0; max = -1; 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': if (*format == 'l') { cflags = DP_C_LLONG; format++; } else cflags = DP_C_LONG; ch = *format++; break; case 'q': 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': switch (cflags) { case DP_C_SHORT: value = va_arg(args, int); break; case DP_C_LONG: value = va_arg(args, long int); break; case DP_C_LLONG: value = va_arg(args, LLONG); break; default: value = va_arg(args, int); break; } fmtint(buffer, &currlen, maxlen, value, 10, min, max, flags); break; case 'X': flags |= DP_F_UP; /* FALLTHROUGH */ case 'x': case 'o': case 'u': flags |= DP_F_UNSIGNED; switch (cflags) { case DP_C_SHORT: value = va_arg(args, unsigned int); break; case DP_C_LONG: value = (LLONG) va_arg(args, unsigned long int); break; case DP_C_LLONG: value = va_arg(args, unsigned LLONG); break; default: value = (LLONG) va_arg(args, unsigned int); break; } fmtint(buffer, &currlen, maxlen, value, ch == 'o' ? 8 : (ch == 'u' ? 10 : 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); 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); 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, min, max, flags); break; case 'p': value = (long)va_arg(args, void *); fmtint(buffer, &currlen, maxlen, value, 16, min, max, flags); break; case 'n': /* XXX */ if (cflags == DP_C_SHORT) { short int *num; num = va_arg(args, short int *); *num = currlen; } else if (cflags == DP_C_LONG) { /* XXX */ long int *num; num = va_arg(args, long int *); *num = (long int) currlen; } else if (cflags == DP_C_LLONG) { /* XXX */ 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 (currlen >= maxlen - 1) currlen = maxlen - 1; buffer[currlen] = '\0'; *retlen = currlen; } static void fmtstr(char *buffer, size_t *currlen, size_t maxlen, char *value, int min, int max, int flags) { int padlen, strln; /* amount to pad */ int cnt = 0; if (value == 0) { value = ""; } 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, LLONG value, int base, int min, int max, int flags) { int signvalue = 0; unsigned LLONG uvalue; char convert[20]; int place = 0; int spadlen = 0; /* amount to space pad */ int zpadlen = 0; /* amount to zero pad */ int caps = 0; if (max < 0) max = 0; uvalue = value; if (!(flags & DP_F_UNSIGNED)) { if (value < 0) { signvalue = '-'; uvalue = -value; } else if (flags & DP_F_PLUS) /* Do a sign (+/i) */ signvalue = '+'; else if (flags & DP_F_SPACE) signvalue = ' '; } if (flags & DP_F_UP) caps = 1; /* Should characters be upper case? */ do { convert[place++] = (caps ? "0123456789ABCDEF" : "0123456789abcdef") [uvalue % (unsigned) base]; uvalue = (uvalue / (unsigned) base); } while (uvalue && (place < 20)); if (place == 20) place--; convert[place] = 0; zpadlen = max - place; spadlen = min - MAX(max, place) - (signvalue ? 1 : 0); if (zpadlen < 0) zpadlen = 0; if (spadlen < 0) spadlen = 0; if (flags & DP_F_ZERO) { zpadlen = MAX(zpadlen, spadlen); spadlen = 0; } if (flags & DP_F_MINUS) spadlen = -spadlen; /* Left Justifty */ #ifdef DEBUG_SNPRINTF printf("zpad: %d, spad: %d, min: %d, max: %d, place: %d\n", zpadlen, spadlen, min, max, place); #endif /* Spaces */ while (spadlen > 0) { dopr_outch(buffer, currlen, maxlen, ' '); --spadlen; } /* Sign */ if (signvalue) dopr_outch(buffer, currlen, maxlen, signvalue); /* Zeros */ if (zpadlen > 0) { while (zpadlen > 0) { dopr_outch(buffer, currlen, maxlen, '0'); --zpadlen; } } /* Digits */ while (place > 0) dopr_outch(buffer, currlen, maxlen, convert[--place]); /* Left Justified spaces */ while (spadlen < 0) { dopr_outch(buffer, currlen, maxlen, ' '); ++spadlen; } } static LDOUBLE abs_val(LDOUBLE value) { LDOUBLE result = value; if (value < 0) result = -value; return result; } static LDOUBLE pow10(int exp) { LDOUBLE result = 1; while (exp) { result *= 10; exp--; } return result; } static long round(LDOUBLE value) { long intpart; intpart = (long) value; value = value - intpart; if (value >= 0.5) intpart++; return intpart; } static void fmtfp(char *buffer, size_t *currlen, size_t maxlen, LDOUBLE fvalue, int min, int max, int flags) { int signvalue = 0; LDOUBLE ufvalue; char iconvert[20]; char fconvert[20]; int iplace = 0; int fplace = 0; int padlen = 0; /* amount to pad */ int zpadlen = 0; int caps = 0; long intpart; long fracpart; /* AIX manpage says the default is 0, but Solaris says the default is * 6, and sprintf on AIX defaults to 6 */ if (max < 0) max = 6; ufvalue = abs_val(fvalue); if (fvalue < 0) signvalue = '-'; else if (flags & DP_F_PLUS) /* Do a sign (+/i) */ signvalue = '+'; else if (flags & DP_F_SPACE) signvalue = ' '; #if 0 if (flags & DP_F_UP) caps = 1; /* Should characters be upper case? */ #endif intpart = (long) ufvalue; /* Sorry, we only support 9 digits past the decimal because of our * conversion method */ if (max > 9) max = 9; /* We "cheat" by converting the fractional part to integer by * multiplying by a factor of 10 */ fracpart = round((pow10(max)) * (ufvalue - intpart)); if (fracpart >= pow10(max)) { intpart++; fracpart -= pow10(max); } #ifdef DEBUG_SNPRINTF printf("fmtfp: %g %d.%d min=%d max=%d\n", (double) fvalue, intpart, fracpart, min, max); #endif /* Convert integer part */ do { iconvert[iplace++] = (caps ? "0123456789ABCDEF" : "0123456789abcdef")[intpart % 10]; intpart = (intpart / 10); } while (intpart && (iplace < 20)); if (iplace == 20) iplace--; iconvert[iplace] = 0; /* Convert fractional part */ do { fconvert[fplace++] = (caps ? "0123456789ABCDEF" : "0123456789abcdef")[fracpart % 10]; fracpart = (fracpart / 10); } while (fracpart && (fplace < 20)); if (fplace == 20) fplace--; fconvert[fplace] = 0; /* -1 for decimal point, another -1 if we are printing a sign */ padlen = min - iplace - max - 1 - ((signvalue) ? 1 : 0); zpadlen = max - fplace; if (zpadlen < 0) zpadlen = 0; if (padlen < 0) padlen = 0; if (flags & DP_F_MINUS) padlen = -padlen; /* Left Justifty */ if ((flags & DP_F_ZERO) && (padlen > 0)) { if (signvalue) { dopr_outch(buffer, currlen, maxlen, signvalue); --padlen; signvalue = 0; } while (padlen > 0) { dopr_outch(buffer, currlen, maxlen, '0'); --padlen; } } while (padlen > 0) { dopr_outch(buffer, currlen, maxlen, ' '); --padlen; } if (signvalue) dopr_outch(buffer, currlen, maxlen, signvalue); while (iplace > 0) dopr_outch(buffer, currlen, maxlen, iconvert[--iplace]); #ifdef DEBUG_SNPRINTF printf("fmtfp: fplace=%d zpadlen=%d\n", fplace, zpadlen); #endif /* * Decimal point. This should probably use locale to find the correct * char to print out. */ if (max > 0) { dopr_outch(buffer, currlen, maxlen, '.'); while (fplace > 0) dopr_outch(buffer, currlen, maxlen, fconvert[--fplace]); } while (zpadlen > 0) { dopr_outch(buffer, currlen, maxlen, '0'); --zpadlen; } while (padlen < 0) { dopr_outch(buffer, currlen, maxlen, ' '); ++padlen; } } static void dopr_outch(char *buffer, size_t *currlen, size_t maxlen, int c) { if (*currlen < maxlen) buffer[(*currlen)++] = (char)c; } int vsnprintf(char *str, size_t count, const char *fmt, va_list args) { size_t retlen; str[0] = 0; dopr(str, count, &retlen, fmt, args); return (retlen); } /* VARARGS3 */ int snprintf(char *str, size_t count, const char *fmt, ...) { va_list ap; int rv; va_start(ap, fmt); rv = vsnprintf(str, count, fmt, ap); va_end(ap); return (rv); } #ifdef TEST_SNPRINTF #ifndef LONG_STRING #define LONG_STRING 1024 #endif int main(int argc, char *argv[]) { char buf1[LONG_STRING]; char buf2[LONG_STRING]; char *fp_fmt[] = { "%-1.5f", "%1.5f", "%123.9f", "%10.5f", "% 10.5f", "%+22.9f", "%+4.9f", "%01.3f", "%4f", "%3.1f", "%3.2f", "%.0f", "%.1f", NULL }; double fp_nums[] = { -1.5, 134.21, 91340.2, 341.1234, 0203.9, 0.96, 0.996, 0.9996, 1.996, 4.136, 0 }; char *int_fmt[] = { "%-1.5d", "%1.5d", "%123.9d", "%5.5d", "%10.5d", "% 10.5d", "%+22.33d", "%01.3d", "%4d", #if HAVE_LONG_LONG "%12lld", #endif NULL }; LLONG int_nums[] = { -1, 134, 91340, 341, 0203, 4294967290, 4294967297, 0 }; int x, y; int fail = 0; int num = 0; int len; printf("Testing snprintf format codes against system sprintf...\n"); for (x = 0; fp_fmt[x] != NULL; x++) { printf("testing %s\n", fp_fmt[x]); for (y = 0; fp_nums[y] != 0; y++) { snprintf(buf1, sizeof(buf1), fp_fmt[x], fp_nums[y]); sprintf(buf2, fp_fmt[x], fp_nums[y]); if (strcmp(buf1, buf2)) { printf("snprintf doesn't match Format: %s\n", fp_fmt[x]); printf("\tsnprintf = %s\n\tsprintf = %s\n", buf1, buf2); fail++; } num++; } } for (x = 0; int_fmt[x] != NULL; x++) { printf("testing %s\n", int_fmt[x]); for (y = 0; int_nums[y] != 0; y++) { len = snprintf(buf1, sizeof(buf1), int_fmt[x], int_nums[y]); printf("got %d >%s< (%d)\n", len, buf1, (int)strlen(buf1)); sprintf(buf2, int_fmt[x], int_nums[y]); if (strcmp(buf1, buf2)) { printf("snprintf doesn't match Format: %s\n", int_fmt[x]); printf("\tsnprintf = %s\n\tsprintf = %s\n", buf1, buf2); fail++; } num++; } } printf("%d tests failed out of %d.\n", fail, num); exit(0); } #endif /* TEST_SNPRINTF */