/* * Copyright (c) 1995 Patrick Powell. * * This code is based on code written by Patrick Powell . * It may be used for any purpose as long as this notice remains intact on all * source code distributions. */ /* * Copyright (c) 2008 Holger Weiss. * * This version of the code is maintained by Holger Weiss . * My changes to the code may freely be used, modified and/or redistributed for * any purpose. It would be nice if additions and fixes to this file (including * trivial code cleanups) would be sent back in order to let me include them in * the version available at . * However, this is not a requirement for using or redistributing (possibly * modified) versions of this file, nor is leaving this notice intact mandatory. */ /* * History * * 2009-03-05 Hector Martin "marcan" * * Hacked up and removed a lot of stuff including floating-point support, * a bunch of ifs and defines, locales, and tests * * 2008-01-20 Holger Weiss for C99-snprintf 1.1: * * Fixed the detection of infinite floating point values on IRIX (and * possibly other systems) and applied another few minor cleanups. * * 2008-01-06 Holger Weiss for C99-snprintf 1.0: * * Added a lot of new features, fixed many bugs, and incorporated various * improvements done by Andrew Tridgell , Russ Allbery * , Hrvoje Niksic , Damien Miller * , and others for the Samba, INN, Wget, and OpenSSH * projects. The additions include: support the "e", "E", "g", "G", and * "F" conversion specifiers (and use conversion style "f" or "F" for the * still unsupported "a" and "A" specifiers); support the "hh", "ll", "j", * "t", and "z" length modifiers; support the "#" flag and the (non-C99) * "'" flag; use localeconv(3) (if available) to get both the current * locale's decimal point character and the separator between groups of * digits; fix the handling of various corner cases of field width and * precision specifications; fix various floating point conversion bugs; * handle infinite and NaN floating point values; don't attempt to write to * the output buffer (which may be NULL) if a size of zero was specified; * check for integer overflow of the field width, precision, and return * values and during the floating point conversion; use the OUTCHAR() macro * instead of a function for better performance; provide asprintf(3) and * vasprintf(3) functions; add new test cases. The replacement functions * have been renamed to use an "rpl_" prefix, the function calls in the * main project (and in this file) must be redefined accordingly for each * replacement function which is needed (by using Autoconf or other means). * Various other minor improvements have been applied and the coding style * was cleaned up for consistency. * * 2007-07-23 Holger Weiss for Mutt 1.5.13: * * C99 compliant snprintf(3) and vsnprintf(3) functions return the number * of characters that would have been written to a sufficiently sized * buffer (excluding the '\0'). The original code simply returned the * length of the resulting output string, so that's been fixed. * * 1998-03-05 Michael Elkins for Mutt 0.90.8: * * The original code assumed that both snprintf(3) and vsnprintf(3) were * missing. Some systems only have snprintf(3) but not vsnprintf(3), so * the code is now broken down under HAVE_SNPRINTF and HAVE_VSNPRINTF. * * 1998-01-27 Thomas Roessler for Mutt 0.89i: * * The PGP code was using unsigned hexadecimal formats. Unfortunately, * unsigned formats simply didn't work. * * 1997-10-22 Brandon Long 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, formatted the code to Mutt conventions, and removed dead code left * over from the original. Also, there is now a builtin-test, run with: * gcc -DTEST_SNPRINTF -o snprintf snprintf.c -lm && ./snprintf * * 2996-09-15 Brandon Long 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. */ #include #include "types.h" #define VA_START(ap, last) va_start(ap, last) #define VA_SHIFT(ap, value, type) /* No-op for ANSI C. */ #define ULLONG unsigned long #define UINTMAX_T unsigned long #define UINTMAX_MAX ULONG_MAX #define LLONG long #define INTMAX_T long /* Support for uintptr_t. */ #ifndef UINTPTR_T #if HAVE_UINTPTR_T || defined(uintptr_t) #define UINTPTR_T uintptr_t #else #define UINTPTR_T unsigned long int #endif /* HAVE_UINTPTR_T || defined(uintptr_t) */ #endif /* !defined(UINTPTR_T) */ /* Support for ptrdiff_t. */ #ifndef PTRDIFF_T #if HAVE_PTRDIFF_T || defined(ptrdiff_t) #define PTRDIFF_T ptrdiff_t #else #define PTRDIFF_T long int #endif /* HAVE_PTRDIFF_T || defined(ptrdiff_t) */ #endif /* !defined(PTRDIFF_T) */ /* * We need an unsigned integer type corresponding to ptrdiff_t (cf. C99: * 7.19.6.1, 7). However, we'll simply use PTRDIFF_T and convert it to an * unsigned type if necessary. This should work just fine in practice. */ #ifndef UPTRDIFF_T #define UPTRDIFF_T PTRDIFF_T #endif /* !defined(UPTRDIFF_T) */ /* * We need a signed integer type corresponding to size_t (cf. C99: 7.19.6.1, 7). * However, we'll simply use size_t and convert it to a signed type if * necessary. This should work just fine in practice. */ #ifndef SSIZE_T #define SSIZE_T size_t #endif /* !defined(SSIZE_T) */ /* * Buffer size to hold the octal string representation of UINT128_MAX without * nul-termination ("3777777777777777777777777777777777777777777"). */ #ifdef MAX_CONVERT_LENGTH #undef MAX_CONVERT_LENGTH #endif /* defined(MAX_CONVERT_LENGTH) */ #define MAX_CONVERT_LENGTH 43 /* Format read states. */ #define PRINT_S_DEFAULT 0 #define PRINT_S_FLAGS 1 #define PRINT_S_WIDTH 2 #define PRINT_S_DOT 3 #define PRINT_S_PRECISION 4 #define PRINT_S_MOD 5 #define PRINT_S_CONV 6 /* Format flags. */ #define PRINT_F_MINUS (1 << 0) #define PRINT_F_PLUS (1 << 1) #define PRINT_F_SPACE (1 << 2) #define PRINT_F_NUM (1 << 3) #define PRINT_F_ZERO (1 << 4) #define PRINT_F_QUOTE (1 << 5) #define PRINT_F_UP (1 << 6) #define PRINT_F_UNSIGNED (1 << 7) #define PRINT_F_TYPE_G (1 << 8) #define PRINT_F_TYPE_E (1 << 9) /* Conversion flags. */ #define PRINT_C_CHAR 1 #define PRINT_C_SHORT 2 #define PRINT_C_LONG 3 #define PRINT_C_LLONG 4 //#define PRINT_C_LDOUBLE 5 #define PRINT_C_SIZE 6 #define PRINT_C_PTRDIFF 7 #define PRINT_C_INTMAX 8 #ifndef MAX #define MAX(x, y) ((x >= y) ? x : y) #endif /* !defined(MAX) */ #ifndef CHARTOINT #define CHARTOINT(ch) (ch - '0') #endif /* !defined(CHARTOINT) */ #ifndef ISDIGIT #define ISDIGIT(ch) ('0' <= (unsigned char)ch && (unsigned char)ch <= '9') #endif /* !defined(ISDIGIT) */ #define OUTCHAR(str, len, size, ch) \ do { \ if (len + 1 < size) \ str[len] = ch; \ (len)++; \ } while (/* CONSTCOND */ 0) static void fmtstr(char *, size_t *, size_t, const char *, int, int, int); static void fmtint(char *, size_t *, size_t, INTMAX_T, int, int, int, int); static void printsep(char *, size_t *, size_t); static int getnumsep(int); static int convert(UINTMAX_T, char *, size_t, int, int); int vsnprintf(char *str, size_t size, const char *format, va_list args) { INTMAX_T value; unsigned char cvalue; const char *strvalue; INTMAX_T *intmaxptr; PTRDIFF_T *ptrdiffptr; SSIZE_T *sizeptr; LLONG *llongptr; long int *longptr; int *intptr; short int *shortptr; signed char *charptr; size_t len = 0; int overflow = 0; int base = 0; int cflags = 0; int flags = 0; int width = 0; int precision = -1; int state = PRINT_S_DEFAULT; char ch = *format++; /* * C99 says: "If `n' is zero, nothing is written, and `s' may be a null * pointer." (7.19.6.5, 2) We're forgiving and allow a NULL pointer * even if a size larger than zero was specified. At least NetBSD's * snprintf(3) does the same, as well as other versions of this file. * (Though some of these versions will write to a non-NULL buffer even * if a size of zero was specified, which violates the standard.) */ if (str == NULL && size != 0) size = 0; while (ch != '\0') switch (state) { case PRINT_S_DEFAULT: if (ch == '%') state = PRINT_S_FLAGS; else OUTCHAR(str, len, size, ch); ch = *format++; break; case PRINT_S_FLAGS: switch (ch) { case '-': flags |= PRINT_F_MINUS; ch = *format++; break; case '+': flags |= PRINT_F_PLUS; ch = *format++; break; case ' ': flags |= PRINT_F_SPACE; ch = *format++; break; case '#': flags |= PRINT_F_NUM; ch = *format++; break; case '0': flags |= PRINT_F_ZERO; ch = *format++; break; case '\'': /* SUSv2 flag (not in C99). */ flags |= PRINT_F_QUOTE; ch = *format++; break; default: state = PRINT_S_WIDTH; break; } break; case PRINT_S_WIDTH: if (ISDIGIT(ch)) { ch = CHARTOINT(ch); if (width > (INT_MAX - ch) / 10) { overflow = 1; goto out; } width = 10 * width + ch; ch = *format++; } else if (ch == '*') { /* * C99 says: "A negative field width argument is * taken as a `-' flag followed by a positive * field width." (7.19.6.1, 5) */ if ((width = va_arg(args, int)) < 0) { flags |= PRINT_F_MINUS; width = -width; } ch = *format++; state = PRINT_S_DOT; } else state = PRINT_S_DOT; break; case PRINT_S_DOT: if (ch == '.') { state = PRINT_S_PRECISION; ch = *format++; } else state = PRINT_S_MOD; break; case PRINT_S_PRECISION: if (precision == -1) precision = 0; if (ISDIGIT(ch)) { ch = CHARTOINT(ch); if (precision > (INT_MAX - ch) / 10) { overflow = 1; goto out; } precision = 10 * precision + ch; ch = *format++; } else if (ch == '*') { /* * C99 says: "A negative precision argument is * taken as if the precision were omitted." * (7.19.6.1, 5) */ if ((precision = va_arg(args, int)) < 0) precision = -1; ch = *format++; state = PRINT_S_MOD; } else state = PRINT_S_MOD; break; case PRINT_S_MOD: switch (ch) { case 'h': ch = *format++; if (ch == 'h') { /* It's a char. */ ch = *format++; cflags = PRINT_C_CHAR; } else cflags = PRINT_C_SHORT; break; case 'l': ch = *format++; if (ch == 'l') { /* It's a long long. */ ch = *format++; cflags = PRINT_C_LLONG; } else cflags = PRINT_C_LONG; break; case 'j': cflags = PRINT_C_INTMAX; ch = *format++; break; case 't': cflags = PRINT_C_PTRDIFF; ch = *format++; break; case 'z': cflags = PRINT_C_SIZE; ch = *format++; break; } state = PRINT_S_CONV; break; case PRINT_S_CONV: switch (ch) { case 'd': /* FALLTHROUGH */ case 'i': switch (cflags) { case PRINT_C_CHAR: value = (signed char)va_arg(args, int); break; case PRINT_C_SHORT: value = (short int)va_arg(args, int); break; case PRINT_C_LONG: value = va_arg(args, long int); break; case PRINT_C_LLONG: value = va_arg(args, LLONG); break; case PRINT_C_SIZE: value = va_arg(args, SSIZE_T); break; case PRINT_C_INTMAX: value = va_arg(args, INTMAX_T); break; case PRINT_C_PTRDIFF: value = va_arg(args, PTRDIFF_T); break; default: value = va_arg(args, int); break; } fmtint(str, &len, size, value, 10, width, precision, flags); break; case 'X': flags |= PRINT_F_UP; /* FALLTHROUGH */ case 'x': base = 16; /* FALLTHROUGH */ case 'o': if (base == 0) base = 8; /* FALLTHROUGH */ case 'u': if (base == 0) base = 10; flags |= PRINT_F_UNSIGNED; switch (cflags) { case PRINT_C_CHAR: value = (unsigned char)va_arg(args, unsigned int); break; case PRINT_C_SHORT: value = (unsigned short int)va_arg(args, unsigned int); break; case PRINT_C_LONG: value = va_arg(args, unsigned long int); break; case PRINT_C_LLONG: value = va_arg(args, ULLONG); break; case PRINT_C_SIZE: value = va_arg(args, size_t); break; case PRINT_C_INTMAX: value = va_arg(args, UINTMAX_T); break; case PRINT_C_PTRDIFF: value = va_arg(args, UPTRDIFF_T); break; default: value = va_arg(args, unsigned int); break; } fmtint(str, &len, size, value, base, width, precision, flags); break; case 'c': cvalue = va_arg(args, int); OUTCHAR(str, len, size, cvalue); break; case 's': strvalue = va_arg(args, char *); fmtstr(str, &len, size, strvalue, width, precision, flags); break; case 'p': /* * C99 says: "The value of the pointer is * converted to a sequence of printing * characters, in an implementation-defined * manner." (C99: 7.19.6.1, 8) */ if ((strvalue = va_arg(args, void *)) == NULL) /* * We use the glibc format. BSD prints * "0x0", SysV "0". */ fmtstr(str, &len, size, "(nil)", width, -1, flags); else { /* * We use the BSD/glibc format. SysV * omits the "0x" prefix (which we emit * using the PRINT_F_NUM flag). */ flags |= PRINT_F_NUM; flags |= PRINT_F_UNSIGNED; fmtint(str, &len, size, (UINTPTR_T)strvalue, 16, width, precision, flags); } break; case 'n': switch (cflags) { case PRINT_C_CHAR: charptr = va_arg(args, signed char *); *charptr = len; break; case PRINT_C_SHORT: shortptr = va_arg(args, short int *); *shortptr = len; break; case PRINT_C_LONG: longptr = va_arg(args, long int *); *longptr = len; break; case PRINT_C_LLONG: llongptr = va_arg(args, LLONG *); *llongptr = len; break; case PRINT_C_SIZE: /* * C99 says that with the "z" length * modifier, "a following `n' conversion * specifier applies to a pointer to a * signed integer type corresponding to * size_t argument." (7.19.6.1, 7) */ sizeptr = va_arg(args, SSIZE_T *); *sizeptr = len; break; case PRINT_C_INTMAX: intmaxptr = va_arg(args, INTMAX_T *); *intmaxptr = len; break; case PRINT_C_PTRDIFF: ptrdiffptr = va_arg(args, PTRDIFF_T *); *ptrdiffptr = len; break; default: intptr = va_arg(args, int *); *intptr = len; break; } break; case '%': /* Print a "%" character verbatim. */ OUTCHAR(str, len, size, ch); break; default: /* Skip other characters. */ break; } ch = *format++; state = PRINT_S_DEFAULT; base = cflags = flags = width = 0; precision = -1; break; } out: if (len < size) str[len] = '\0'; else if (size > 0) str[size - 1] = '\0'; if (overflow || len >= INT_MAX) { return -1; } return (int)len; } static void fmtstr(char *str, size_t *len, size_t size, const char *value, int width, int precision, int flags) { int padlen, strln; /* Amount to pad. */ int noprecision = (precision == -1); if (value == NULL) /* We're forgiving. */ value = "(null)"; /* If a precision was specified, don't read the string past it. */ for (strln = 0; value[strln] != '\0' && (noprecision || strln < precision); strln++) continue; if ((padlen = width - strln) < 0) padlen = 0; if (flags & PRINT_F_MINUS) /* Left justify. */ padlen = -padlen; while (padlen > 0) { /* Leading spaces. */ OUTCHAR(str, *len, size, ' '); padlen--; } while (*value != '\0' && (noprecision || precision-- > 0)) { OUTCHAR(str, *len, size, *value); value++; } while (padlen < 0) { /* Trailing spaces. */ OUTCHAR(str, *len, size, ' '); padlen++; } } static void fmtint(char *str, size_t *len, size_t size, INTMAX_T value, int base, int width, int precision, int flags) { UINTMAX_T uvalue; char iconvert[MAX_CONVERT_LENGTH]; char sign = 0; char hexprefix = 0; int spadlen = 0; /* Amount to space pad. */ int zpadlen = 0; /* Amount to zero pad. */ int pos; int separators = (flags & PRINT_F_QUOTE); int noprecision = (precision == -1); if (flags & PRINT_F_UNSIGNED) uvalue = value; else { uvalue = (value >= 0) ? value : -value; if (value < 0) sign = '-'; else if (flags & PRINT_F_PLUS) /* Do a sign. */ sign = '+'; else if (flags & PRINT_F_SPACE) sign = ' '; } pos = convert(uvalue, iconvert, sizeof(iconvert), base, flags & PRINT_F_UP); if (flags & PRINT_F_NUM && uvalue != 0) { /* * C99 says: "The result is converted to an `alternative form'. * For `o' conversion, it increases the precision, if and only * if necessary, to force the first digit of the result to be a * zero (if the value and precision are both 0, a single 0 is * printed). For `x' (or `X') conversion, a nonzero result has * `0x' (or `0X') prefixed to it." (7.19.6.1, 6) */ switch (base) { case 8: if (precision <= pos) precision = pos + 1; break; case 16: hexprefix = (flags & PRINT_F_UP) ? 'X' : 'x'; break; } } if (separators) /* Get the number of group separators we'll print. */ separators = getnumsep(pos); zpadlen = precision - pos - separators; spadlen = width /* Minimum field width. */ - separators /* Number of separators. */ - MAX(precision, pos) /* Number of integer digits. */ - ((sign != 0) ? 1 : 0) /* Will we print a sign? */ - ((hexprefix != 0) ? 2 : 0); /* Will we print a prefix? */ if (zpadlen < 0) zpadlen = 0; if (spadlen < 0) spadlen = 0; /* * C99 says: "If the `0' and `-' flags both appear, the `0' flag is * ignored. For `d', `i', `o', `u', `x', and `X' conversions, if a * precision is specified, the `0' flag is ignored." (7.19.6.1, 6) */ if (flags & PRINT_F_MINUS) /* Left justify. */ spadlen = -spadlen; else if (flags & PRINT_F_ZERO && noprecision) { zpadlen += spadlen; spadlen = 0; } while (spadlen > 0) { /* Leading spaces. */ OUTCHAR(str, *len, size, ' '); spadlen--; } if (sign != 0) /* Sign. */ OUTCHAR(str, *len, size, sign); if (hexprefix != 0) { /* A "0x" or "0X" prefix. */ OUTCHAR(str, *len, size, '0'); OUTCHAR(str, *len, size, hexprefix); } while (zpadlen > 0) { /* Leading zeros. */ OUTCHAR(str, *len, size, '0'); zpadlen--; } while (pos > 0) { /* The actual digits. */ pos--; OUTCHAR(str, *len, size, iconvert[pos]); if (separators > 0 && pos > 0 && pos % 3 == 0) printsep(str, len, size); } while (spadlen < 0) { /* Trailing spaces. */ OUTCHAR(str, *len, size, ' '); spadlen++; } } static void printsep(char *str, size_t *len, size_t size) { OUTCHAR(str, *len, size, ','); } static int getnumsep(int digits) { int separators = (digits - ((digits % 3 == 0) ? 1 : 0)) / 3; return separators; } static int convert(UINTMAX_T value, char *buf, size_t size, int base, int caps) { const char *digits = caps ? "0123456789ABCDEF" : "0123456789abcdef"; size_t pos = 0; /* We return an unterminated buffer with the digits in reverse order. */ do { buf[pos++] = digits[value % base]; value /= base; } while (value != 0 && pos < size); return (int)pos; } int vsprintf(char *buf, const char *fmt, va_list args) { return vsnprintf(buf, INT_MAX, fmt, args); }