/* $OpenBSD: vfscanf.c,v 1.16 2005/12/19 19:39:25 millert 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 #include #include #include #include #include #ifdef FLOATING_POINT /* 11-bit exponent (VAX G floating point) is 308 decimal digits */ #define MAXEXP 308 /* 128 bit fraction takes up 39 decimal digits; max reasonable precision */ #define MAXFRACT 39 #endif #define BUF 513 /* Maximum length of numeric string. */ /* * Flags used during conversion. */ #define LONG 0x0001 /* l: long or double */ #define LONGDBL 0x0002 /* L: long double; unimplemented */ #define SHORT 0x0004 /* h: short */ #define QUAD 0x0008 /* q: quad */ #define SUPPRESS 0x0010 /* suppress assignment */ #define POINTER 0x0020 /* weird %p pointer (`fake hex') */ #define NOSKIP 0x0040 /* do not skip blanks */ #define SHORTSHORT 0x0080 /* hh: 8 bit integer */ #define SIZEINT 0x0100 /* z: (signed) size_t */ /* -- MammouthServer extensions -- */ /* * This modified scanf function is based upon the original * scanf of the OpenBSD libc, so if I did not fscked it up too * much, it should be reliable :) * * The first thing which was modified is the return value of * scanf. This function returns the number of bytes which were * read, not the number of fields filled. * * The scanf behaviour has slightly changed too; now, if an * input or match failure occurs, it returns -1. Some fields * may have however be altered before failure. * * If an input failure occurs, the function returns -1 and * EAGAIN. If a match failure happens, it will return -1 and * set errno to ENOMEM. * * But most of the changes are introduced by a couple flags, * b and t. * * These new flags allow to read binary values from a buffer. * * To read binary data, it is required to add the 'b' flag to the * format string. Using the 'b' flag alone implies using the * system endianness. * * However, the binary data endianness may be enforced using * the bB (big endian) or bb (little endian) combinations. * If the enforced endianness matches the system endianness, * nothing special will be done, but otherwise the data will * be swapped. * * e.g: you want to read a big endian integer, on a * little endian machine: * * snscanf(buf, sizeof(buf), "%bBi", & i); * original raw data in 'buf' (big endian seen by little endian): * 0xEFBEADDE * data stored in 'i' (little endian): * 0xDEADBEEF * * It is also possible to force the binary data size, using the * classical field width syntax, or the MammouthServer variable * length extension '$'.[1] * * This said, forcing the type width only works 'as expected' * with *complete* binary types of the forced length. It will * indeed return the n lower or higher bytes of a wider type * depending on the system endianness (swapped if another endianness * was enforced). * So, if you want to truncate a wider data type, you should use the * t/T (or tL/tH) flags to reliably get its lower/higher bytes. * * NB: The binary data type is still mandatory (dioux). * * So, it is correct to use the formats : * %3bBti to read the 24 lower bits of a big endian integer * %3bBi reads a 24 bits big endian integer just fine * %4bbTlli returns the higher 32 bits of a little endian long long * %bi reads an integer of system width and endianness * but the next are not valid or dangerous formats : * %3bBt invalid (missing type) * %2bi (it will return lower/higher two bytes of the data depending * on the system endianness, and the data are assumed to use * the system endianness -- it may be perfectly fine, if that * was the intented purpose :) ) * * * [1] About the variable field width extension * * It works just like '*' in the printf family, except it uses the * '$' flag ('*' has another meaning with scanf, see the manual for * further details), and that it works for strings, too. * * So, '$' define the field width, but unlike the printf '*' it * does not imply padding. In this implementation, it is designed * to limit the number of bytes which can be stored in the output * variable (useful to avoid a buffer overflow with %s). * * E.g: * * snscanf(buffer, sizeof(buffer), "%$s", sizeof(outbuf), outbuf); * will read a string from 'buffer' until a space is encoutered, or * sizeof(outbuf) - 1 bytes were written in 'outbuf', whichever occurs * first. If the field width is reached, a trailing NUL is appended * and the function returns -1, ENOMEM. * */ #define BINARY 0x0200 /* b: binary type, system endian */ #define BIG 0x0400 /* B: force big endian */ #define LITTLE 0x0800 /* bb: force little endian */ #define TRUNK 0x1000 /* t,T: truncate binary (get lower/higher bytes) */ #define HIBYTES 0x2000 /* tH: truncate and get higher bytes */ #define LOBYTES 0x4000 /* tL: truncate and get lower bytes */ /* -- End of MammouthServer extensions -- */ /* * The following are used in numeric conversions only: * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point; * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral. */ #define SIGNOK 0x080 /* +/- is (still) legal */ #define NDIGITS 0x100 /* no digits detected */ #define DPTOK 0x200 /* (float) decimal point is still legal */ #define EXPOK 0x400 /* (float) exponent (e+3, etc) still legal */ #define PFXOK 0x200 /* 0x prefix is (still) legal */ #define NZDIGITS 0x400 /* no zero digits detected */ /* * Conversion types. */ #define CT_CHAR 0 /* %c conversion */ #define CT_CCL 1 /* %[...] conversion */ #define CT_STRING 2 /* %s conversion */ #define CT_INT 3 /* integer, i.e., strtoq or strtouq */ #define CT_FLOAT 4 /* floating, i.e., strtod */ #define u_char unsigned char #define u_long unsigned long #define quad_t long long #define u_quad_t unsigned long long #define ssize_t long static u_char *__sccl(char *, u_char *); static u_quad_t _fetch_int(const u_char *, size_t, int); #define FLOATING_POINT #ifdef FLOATING_POINT static long double _fetch_float(const u_char *, size_t, int); #endif /* * vfscanf */ int vsnscanf(const char *buffer, size_t bufsize, const char *fmt0, va_list ap) { u_char *fmt = (u_char *)fmt0; int c; /* character from format, or conversion */ size_t width; /* field width, or 0 */ char *p; /* points into all kinds of strings */ int n; /* handy integer */ int flags; /* flags as defined above */ char *p0; /* saves original value of p when necessary */ int nassigned; /* number of fields assigned */ int nread; /* number of characters consumed from fp */ int base; /* base argument to strtoq/strtouq */ u_quad_t (*ccfn)(); /* conversion function (strtoq/strtouq) */ char ccltab[256]; /* character class table for %[...] */ char buf[BUF]; /* buffer for numeric conversions */ u_char *b = (u_char *) buffer; /* `basefix' is used to avoid `if' tests in the integer scanner */ static short basefix[17] = { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }; nassigned = 0; nread = 0; base = 0; /* XXX just to keep gcc happy */ ccfn = NULL; /* XXX just to keep gcc happy */ for (;;) { c = *fmt++; if (c == 0) return nread; if (isspace(c)) { while ((bufsize > 0) && isspace(*b)) nread++, bufsize--, b++; continue; } if (c != '%') goto literal; width = 0; flags = 0; /* * switch on the format. continue if done; * break once format type is derived. */ again: c = *fmt++; switch (c) { case '%': literal: if (bufsize <= 0 /*&& __srefill(fp)*/) goto input_failure; if (*b != c) goto match_failure; bufsize--, b++; nread++; continue; case '*': flags |= SUPPRESS; goto again; case 'L': /* -- MammouthServer extensions -- */ if (flags & TRUNK) { flags &= ~HIBYTES; flags |= LOBYTES; } else { flags |= LONGDBL; } goto again; /* -- End of MammouthServer extensions -- */ case 'h': if (*fmt == 'h') { fmt++; flags |= SHORTSHORT; } else { flags |= SHORT; } goto again; case 'l': if (*fmt == 'l') { fmt++; flags |= QUAD; } else { flags |= LONG; } goto again; case 'q': flags |= QUAD; goto again; case 'z': flags |= SIZEINT; goto again; /* -- MammouthServer extensions -- */ case 'b': flags |= (flags & BINARY) ? LITTLE : BINARY; goto again; case 'B': flags |= BIG; goto again; case 't': flags |= TRUNK; flags |= LOBYTES; goto again; case 'T': flags |= TRUNK; flags |= HIBYTES; goto again; case 'H': if (flags & TRUNK) { flags &= ~LOBYTES; flags |= HIBYTES; } goto again; case '$': width = va_arg(ap, size_t); goto again; /* -- End of MammouthServer extensions -- */ case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': width = width * 10 + c - '0'; goto again; /* * Conversions. * Those marked `compat' are for 4.[123]BSD compatibility. * * (According to ANSI, E and X formats are supposed * to the same as e and x. Sorry about that.) */ case 'D': /* compat */ flags |= LONG; /* FALLTHROUGH */ case 'd': c = CT_INT; ccfn = (u_quad_t (*)()) strtoll; base = 10; break; case 'i': c = CT_INT; ccfn = (u_quad_t (*)()) strtoll; base = 0; break; case 'O': /* compat */ flags |= LONG; /* FALLTHROUGH */ case 'o': c = CT_INT; ccfn = strtoull; base = 8; break; case 'u': c = CT_INT; ccfn = strtoull; base = 10; break; case 'X': case 'x': flags |= PFXOK; /* enable 0x prefixing */ c = CT_INT; ccfn = strtoull; base = 16; break; #ifdef FLOATING_POINT case 'E': case 'G': case 'e': case 'f': case 'g': c = CT_FLOAT; break; #endif case 's': c = CT_STRING; break; case '[': fmt = __sccl(ccltab, fmt); flags |= NOSKIP; c = CT_CCL; break; case 'c': flags |= NOSKIP; c = CT_CHAR; break; case 'p': /* pointer format is like hex */ flags |= POINTER | PFXOK; c = CT_INT; ccfn = strtoull; base = 16; break; case 'n': if (flags & SUPPRESS) /* ??? */ continue; if (flags & SHORTSHORT) *va_arg(ap, __signed char *) = nread; else if (flags & SHORT) *va_arg(ap, short *) = nread; else if (flags & LONG) *va_arg(ap, long *) = nread; else if (flags & QUAD) *va_arg(ap, quad_t *) = nread; else if (flags & SIZEINT) *va_arg(ap, ssize_t *) = nread; else *va_arg(ap, int *) = nread; continue; /* * Disgusting backwards compatibility hacks. XXX */ case '\0': /* compat */ return (EOF); default: /* compat */ if (isupper(c)) flags |= LONG; c = CT_INT; ccfn = (u_quad_t (*)()) strtoll; base = 10; break; } /* * We have a conversion that requires input. */ if (bufsize <= 0) goto input_failure; /* * Consume leading white space, except for formats * that suppress this. */ if ((flags & NOSKIP) == 0) { while (isspace(*b)) { nread++; if (--bufsize > 0) b++; else goto input_failure; } /* * Note that there is at least one character in * the buffer, so conversions that do not set NOSKIP * ca no longer result in an input failure. */ } /* * Do the conversion. */ switch (c) { case CT_CHAR: /* scan arbitrary characters (sets NOSKIP) */ if (width == 0) width = 1; if (flags & SUPPRESS) { size_t sum = 0; for (;;) { if ((n = bufsize) < width) { sum += n; width -= n; b += n; if (sum == 0) goto input_failure; break; } else { sum += width; bufsize -= width; b += width; break; } } nread += sum; } else { if (bufsize < width) goto input_failure; memcpy((void *) va_arg(ap, char *), b, width); nread += width; b += width; nassigned ++; } break; case CT_CCL: /* scan a (nonempty) character class (sets NOSKIP) */ if (width == 0) width = (size_t)~0; /* `infinity' */ /* take only those things in the class */ if (flags & SUPPRESS) { n = 0; while (ccltab[*b]) { n++, bufsize--, b++; if (--width == 0) break; if (bufsize <= 0) { if (n == 0) goto input_failure; break; } } if (n == 0) goto match_failure; } else { p0 = p = va_arg(ap, char *); while (ccltab[*b]) { bufsize--; *p++ = *b++; if (--width == 0) break; if (bufsize <= 0) { if (p == p0) goto input_failure; break; } } n = p - p0; if (n == 0) goto match_failure; *p = '\0'; nassigned++; } nread += n; break; case CT_STRING: /* like CCL, but zero-length string OK, & no NOSKIP */ if (width == 0) width = (size_t)~0; if (flags & SUPPRESS) { n = 0; while (!isspace(*b)) { n++, bufsize--, b++; if (--width == 0) break; if (bufsize <= 0) break; } nread += n; } else { p0 = p = va_arg(ap, char *); while (!isspace(*b)) { bufsize--; *p++ = *b++; if (--width == 0) break; if (bufsize <= 0) break; } *p = '\0'; nread += p - p0; nassigned++; } continue; case CT_INT: if (flags & BINARY) { /* no scan, but check the buffer length */ if (! width || width >= sizeof(long double)) { if (flags & POINTER) width = sizeof(int *); else if (flags & SIZEINT) width = sizeof(ssize_t); else if (flags & QUAD) width = sizeof(quad_t); else if (flags & LONG) width = sizeof(long); else if (flags & SHORT) width = sizeof(short); else if (flags & SHORTSHORT) width = sizeof(char); else width = sizeof(int); } if (bufsize - width < 0) goto input_failure; } else { /* scan an integer as if by strtoq/strtouq */ #ifdef hardway if (width == 0 || width > sizeof(buf) - 1) width = sizeof(buf) - 1; #else /* size_t is unsigned, hence this optimisation */ if (--width > sizeof(buf) - 2) width = sizeof(buf) - 2; width++; #endif flags |= SIGNOK | NDIGITS | NZDIGITS; for (p = buf; width; width--) { c = *b; /* * Switch on the character; `goto ok' * if we accept it as a part of number. */ switch (c) { /* * The digit 0 is always legal, but is * special. For %i conversions, if no * digits (zero or nonzero) have been * scanned (only signs), we will have * base==0. In that case, we should set * it to 8 and enable 0x prefixing. * Also, if we have not scanned zero digits * before this, do not turn off prefixing * (someone else will turn it off if we * have scanned any nonzero digits). */ case '0': if (base == 0) { base = 8; flags |= PFXOK; } if (flags & NZDIGITS) flags &= ~(SIGNOK|NZDIGITS|NDIGITS); else flags &= ~(SIGNOK|PFXOK|NDIGITS); goto ok; /* 1 through 7 always legal */ case '1': case '2': case '3': case '4': case '5': case '6': case '7': base = basefix[base]; flags &= ~(SIGNOK | PFXOK | NDIGITS); goto ok; /* digits 8 and 9 ok iff decimal or hex */ case '8': case '9': base = basefix[base]; if (base <= 8) break; /* not legal here */ flags &= ~(SIGNOK | PFXOK | NDIGITS); goto ok; /* letters ok iff hex */ case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': /* no need to fix base here */ if (base <= 10) break; /* not legal here */ flags &= ~(SIGNOK | PFXOK | NDIGITS); goto ok; /* sign ok only as first character */ case '+': case '-': if (flags & SIGNOK) { flags &= ~SIGNOK; goto ok; } break; /* x ok iff flag still set & 2nd char */ case 'x': case 'X': if (flags & PFXOK && p == buf + 1) { base = 16; /* if %i */ flags &= ~PFXOK; goto ok; } break; } /* * If we got here, c is not a legal character * for a number. Stop accumulating digits. */ break; ok: /* * c is legal: store it and look at the next. */ *p++ = c; if (--bufsize > 0) b++; else break; /* EOF */ } /* * If we had only a sign, it is no good; push * back the sign. If the number ends in `x', * it was [sign] '0' 'x', so push back the x * and treat it as [sign] '0'. */ if (flags & NDIGITS) { goto match_failure; } c = ((u_char *)p)[-1]; if (c == 'x' || c == 'X') --p; } if ((flags & SUPPRESS) == 0) { u_quad_t res; if (flags & BINARY) { res = _fetch_int(b, width, flags); b += width; bufsize -= width; } else { *p = '\0'; res = (*ccfn)(buf, (char **) NULL, base); } if (flags & POINTER) *va_arg(ap, void **) = (void *)(long)res; else if (flags & SIZEINT) *va_arg(ap, ssize_t *) = res; else if (flags & QUAD) *va_arg(ap, quad_t *) = res; else if (flags & LONG) *va_arg(ap, long *) = res; else if (flags & SHORT) *va_arg(ap, short *) = res; else if (flags & SHORTSHORT) *va_arg(ap, __signed char *) = res; else *va_arg(ap, int *) = res; nassigned++; } nread += (flags & BINARY) ? width : p - buf; break; #ifdef FLOATING_POINT case CT_FLOAT: if (flags & BINARY) { /* no scan, but check the buffer length */ if (! width || width >= sizeof(long double)) { if (flags & LONGDBL) width = sizeof(long double); else if (flags & LONG) width = sizeof(double); else width = sizeof(float); } if (bufsize - width < 0) goto input_failure; } else { /* scan a floating point number as if by strtod */ #ifdef hardway if (width == 0 || width > sizeof(buf) - 1) width = sizeof(buf) - 1; #else /* size_t is unsigned, hence this optimisation */ if (--width > sizeof(buf) - 2) width = sizeof(buf) - 2; width++; #endif flags |= SIGNOK | NDIGITS | DPTOK | EXPOK; for (p = buf; width; width--) { c = *b; /* * This code mimicks the integer conversion * code, but is much simpler. */ switch (c) { case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': flags &= ~(SIGNOK | NDIGITS); goto fok; case '+': case '-': if (flags & SIGNOK) { flags &= ~SIGNOK; goto fok; } break; case '.': if (flags & DPTOK) { flags &= ~(SIGNOK | DPTOK); goto fok; } break; case 'e': case 'E': /* no exponent without some digits */ if ((flags&(NDIGITS|EXPOK)) == EXPOK) { flags = (flags & ~(EXPOK|DPTOK)) | SIGNOK | NDIGITS; goto fok; } break; } break; fok: *p++ = c; if (--bufsize > 0) b++; else break; /* EOF */ } /* * If no digits, might be missing exponent digits * (just give back the exponent) or might be missing * regular digits, but had sign and/or decimal point. */ if (flags & NDIGITS) { if (flags & EXPOK) { /* no digits at all */ goto match_failure; } /* just a bad exponent (e and maybe sign) */ c = *(u_char *)--p; if (c != 'e' && c != 'E') { /* sign */ c = *(u_char *) --p; } } } if ((flags & SUPPRESS) == 0) { double res; if (flags & BINARY) { res = _fetch_float(b, width, flags); b += width; bufsize -= width; } else { *p = '\0'; res = strtod(buf, (char **) NULL); } if (flags & LONGDBL) *va_arg(ap, long double *) = res; else if (flags & LONG) *va_arg(ap, double *) = res; else *va_arg(ap, float *) = res; nassigned++; } nread += (flags & BINARY) ? width : p - buf; break; #endif /* FLOATING_POINT */ } } input_failure: errno = ENOMEM; return -1; match_failure: errno = EAGAIN; printf("match failure\n"); return -1; } /* * Fill in the given table from the scanset at the given format * (just after `['). Return a pointer to the character past the * closing `]'. The table has a 1 wherever characters should be * considered part of the scanset. */ static u_char *__sccl(char *tab, u_char *fmt) { int c, n, v; /* first `clear' the whole table */ c = *fmt++; /* first char hat => negated scanset */ if (c == '^') { v = 1; /* default => accept */ c = *fmt++; /* get new first char */ } else v = 0; /* default => reject */ /* should probably use memset here */ for (n = 0; n < 256; n++) tab[n] = v; if (c == 0) return (fmt - 1);/* format ended before closing ] */ /* * Now set the entries corresponding to the actual scanset * to the opposite of the above. * * The first character may be ']' (or '-') without being special; * the last character may be '-'. */ v = 1 - v; for (;;) { tab[c] = v; /* take character c */ doswitch: n = *fmt++; /* and examine the next */ switch (n) { case 0: /* format ended too soon */ return (fmt - 1); case '-': /* * A scanset of the form * [01+-] * is defined as `the digit 0, the digit 1, * the character +, the character -', but * the effect of a scanset such as * [a-zA-Z0-9] * is implementation defined. The V7 Unix * scanf treats `a-z' as `the letters a through * z', but treats `a-a' as `the letter a, the * character -, and the letter a'. * * For compatibility, the `-' is not considerd * to define a range if the character following * it is either a close bracket (required by ANSI) * or is not numerically greater than the character * we just stored in the table (c). */ n = *fmt; if (n == ']' || n < c) { c = '-'; break; /* resume the for(;;) */ } fmt++; do { /* fill in the range */ tab[++c] = v; } while (c < n); #if 1 /* XXX another disgusting compatibility hack */ /* * Alas, the V7 Unix scanf also treats formats * such as [a-c-e] as `the letters a through e'. * This too is permitted by the standard.... */ goto doswitch; #else c = *fmt++; if (c == 0) return (fmt - 1); if (c == ']') return (fmt); #endif break; case ']': /* end of scanset */ return (fmt); default: /* just another character */ c = n; break; } } /* NOTREACHED */ } static u_quad_t _fetch_int(const u_char *b, size_t w, int flags) { u_quad_t ret = 1; int sys_endian = 0; /* 0 == big endian, little endian otherwise */ if (*(char *) & ret == 1) sys_endian = 1; if (flags & BIG) sys_endian = 0; else if (flags & LITTLE) sys_endian = 1; if (flags & TRUNK) { if ( (sys_endian == 1 && (flags & HIBYTES)) || (sys_endian == 0 && (flags & LOBYTES)) ) { /* should begin from the MSB */ if (flags & POINTER) b += sizeof(int *); else if (flags & SIZEINT) b += sizeof(ssize_t); else if (flags & QUAD) b += sizeof(quad_t); else if (flags & LONG) b += sizeof(long); else if (flags & SHORT) b += sizeof(short); else if (flags & SHORTSHORT) b += sizeof(char); else b += sizeof(int); b -= w; } } ret = 0; /* fetch bytes, storing them using the given endianness */ if (sys_endian) { while (w --) ret += ((u_quad_t) b[w]) << (w * CHAR_BIT); } else { size_t i = 0; while (w --) ret += ((u_quad_t) b[w]) << (i ++ * CHAR_BIT); } return ret; } #ifdef FLOATING_POINT static long double _fetch_float(const u_char *b, size_t w, int flags) { long double ret = 1; int sys_endian = 0; /* 0 == big endian, little endian otherwise */ if (*(char *) & ret == 1) sys_endian = 1; if (flags & BIG) sys_endian = 0; else if (flags & LITTLE) sys_endian = 1; if (flags & TRUNK) { if ( (sys_endian == 1 && (flags & HIBYTES)) || (sys_endian == 0 && (flags & LOBYTES)) ) { /* should begin from the MSB */ if (flags & LONGDBL) b += sizeof(long double); else if (flags & LONG) b += sizeof(double); else b += sizeof(float); b -= w; } } ret = 0; /* fetch bytes, storing them using the given endianness */ if (sys_endian) { while (w --) ret += ((u_quad_t) b[w]) << (w * CHAR_BIT); } else { size_t i = 0; while (w --) ret += ((u_quad_t) b[w]) << (i ++ * CHAR_BIT); } return ret; } #endif int snscanf(const char *buffer, size_t size, const char *fmt, ...) { int ret = 0; va_list ap; va_start(ap, fmt); ret = vsnscanf(buffer, size, fmt, ap); va_end(ap); return ret; } int main(void) { const char string[] = "HTTP/1.1 200 OK\r\n" "Date: Wed, 28 Dec 2005 19:17:10 GMT\r\n" "Server: Apache/1.3.34 (Unix) PHP/5.0.5\r\n" "Content-Location: index.html.en\r\n" "Vary: negotiate,accept-language,accept-charset\r\n" "TCN: choice\r\n" "Last-Modified: Mon, 24 Oct 2005 19:08:21 GMT\r\n" "ETag: \"1131f-a71-435d3125;43ab5b00\"\r\n" "Accept-Ranges: bytes\r\n" "Content-Length: 2673\r\n" "Content-Type: text/html\r\n" "Content-Language: en\r\n" "\r\n"; const size_t len = strlen(string); char buffer[256]; int i = 0, r = 0; char int_buffer[sizeof(i)]; u_quad_t ll = 0xDEC0ADEBAF0C0000; /* 0xCAFEBADCODE in opposite endianness */ char long_buffer[sizeof(ll)]; float f = 1337.1234; char float_buffer[sizeof(f)]; memset(buffer, 0, sizeof(buffer)); /* test the Mammouth Extension '$' for variable field width */ while ( (i = snscanf(string + r, len - r,"%$[^\r\n]%*c%*c", 255, buffer)) > 0) { r += i; printf("returns %i, buffer=%s\n", i, buffer); memset(buffer, 0, sizeof(buffer)); } /* system integer test */ i = 0xCAFE; memcpy(int_buffer, (char *) & i, sizeof(i)); i = 0; r = snscanf(int_buffer, sizeof(int_buffer), "%bi", & i); printf("returns %i, i = 0x%X\n", r, i); printf("long long, opposite endianness : 0x%llX\n", ll); memcpy(long_buffer, (char *) & ll, sizeof(ll)); if ( (ll = 1) && (*(char *) & ll) == 1) { /* run on a little endian platform */ r = snscanf(long_buffer, sizeof(long_buffer), "%bBlli", & ll); } else { /* big endian platform */ r = snscanf(long_buffer, sizeof(long_buffer), "%bblli", & ll); } printf("returns %i, i = 0x%llX\n", r, ll); printf("float, system endianness : %f (0x%x)\n", f, (int) f); memcpy(float_buffer, (char *) & f, sizeof(f)); f = 0; r = snscanf(float_buffer, sizeof(long_buffer), "%bf", & f); printf("BUG: returns %i, i = %f (0x%x)\n", r, f, (int) f); r = snscanf(float_buffer, sizeof(long_buffer), "%bi", & f); printf("XXX: returns %i, i = %f (0x%x)\n", r, f, (int) f); return 0; }