+ va_start(ap, fmt);
+ str_l = portable_vsnprintf(str, str_m, fmt, ap);
+ va_end(ap);
+ return str_l;
+}
+#endif
+
+#if defined(NEED_SNPRINTF_ONLY)
+int portable_snprintf(char *str, size_t str_m, const char *fmt, /*args*/ ...) {
+#else
+int portable_vsnprintf(char *str, size_t str_m, const char *fmt, va_list ap) {
+#endif
+
+#if defined(NEED_SNPRINTF_ONLY)
+ va_list ap;
+#endif
+ size_t str_l = 0;
+ const char *p = fmt;
+
+/* In contrast with POSIX, the ISO C99 now says
+ * that str can be NULL and str_m can be 0.
+ * This is more useful than the old: if (str_m < 1) return -1; */
+
+#if defined(NEED_SNPRINTF_ONLY)
+ va_start(ap, fmt);
+#endif
+ if (!p) p = "";
+ while (*p) {
+ if (*p != '%') {
+ /* if (str_l < str_m) str[str_l++] = *p++; -- this would be sufficient */
+ /* but the following code achieves better performance for cases
+ * where format string is long and contains few conversions */
+ const char *q = strchr(p+1,'%');
+ size_t n = !q ? strlen(p) : (q-p);
+ if (str_l < str_m) {
+ size_t avail = str_m-str_l;
+ fast_memcpy(str+str_l, p, (n>avail?avail:n));
+ }
+ p += n; str_l += n;
+ } else {
+ const char *starting_p;
+ size_t min_field_width = 0, precision = 0;
+ int zero_padding = 0, precision_specified = 0, justify_left = 0;
+ int alternate_form = 0, force_sign = 0;
+ int space_for_positive = 1; /* If both the ' ' and '+' flags appear,
+ the ' ' flag should be ignored. */
+ char length_modifier = '\0'; /* allowed values: \0, h, l, L */
+ char tmp[32];/* temporary buffer for simple numeric->string conversion */
+
+ const char *str_arg; /* string address in case of string argument */
+ size_t str_arg_l; /* natural field width of arg without padding
+ and sign */
+ unsigned char uchar_arg;
+ /* unsigned char argument value - only defined for c conversion.
+ N.B. standard explicitly states the char argument for
+ the c conversion is unsigned */
+
+ size_t number_of_zeros_to_pad = 0;
+ /* number of zeros to be inserted for numeric conversions
+ as required by the precision or minimal field width */
+
+ size_t zero_padding_insertion_ind = 0;
+ /* index into tmp where zero padding is to be inserted */
+
+ char fmt_spec = '\0';
+ /* current conversion specifier character */
+
+ str_arg = credits;/* just to make compiler happy (defined but not used)*/
+ str_arg = NULL;
+ starting_p = p; p++; /* skip '%' */
+ /* parse flags */
+ while (*p == '0' || *p == '-' || *p == '+' ||
+ *p == ' ' || *p == '#' || *p == '\'') {
+ switch (*p) {
+ case '0': zero_padding = 1; break;
+ case '-': justify_left = 1; break;
+ case '+': force_sign = 1; space_for_positive = 0; break;
+ case ' ': force_sign = 1;
+ /* If both the ' ' and '+' flags appear, the ' ' flag should be ignored */
+#ifdef PERL_COMPATIBLE
+ /* ... but in Perl the last of ' ' and '+' applies */
+ space_for_positive = 1;
+#endif
+ break;
+ case '#': alternate_form = 1; break;
+ case '\'': break;
+ }
+ p++;
+ }
+ /* If the '0' and '-' flags both appear, the '0' flag should be ignored. */
+
+ /* parse field width */
+ if (*p == '*') {
+ int j;
+ p++; j = va_arg(ap, int);
+ if (j >= 0) min_field_width = j;
+ else { min_field_width = -j; justify_left = 1; }
+ } else if (isdigit((int)(*p))) {
+ /* size_t could be wider than unsigned int;
+ make sure we treat argument like common implementations do */
+ unsigned int uj = *p++ - '0';
+ while (isdigit((int)(*p))) uj = 10*uj + (unsigned int)(*p++ - '0');
+ min_field_width = uj;
+ }
+ /* parse precision */
+ if (*p == '.') {
+ p++; precision_specified = 1;
+ if (*p == '*') {
+ int j = va_arg(ap, int);
+ p++;
+ if (j >= 0) precision = j;
+ else {
+ precision_specified = 0; precision = 0;
+ /* NOTE:
+ * Solaris 2.6 man page claims that in this case the precision
+ * should be set to 0. Digital Unix 4.0, HPUX 10 and BSD man page
+ * claim that this case should be treated as unspecified precision,
+ * which is what we do here.
+ */
+ }
+ } else if (isdigit((int)(*p))) {
+ /* size_t could be wider than unsigned int;
+ make sure we treat argument like common implementations do */
+ unsigned int uj = *p++ - '0';
+ while (isdigit((int)(*p))) uj = 10*uj + (unsigned int)(*p++ - '0');
+ precision = uj;
+ }
+ }
+ /* parse 'h', 'l' and 'll' length modifiers */
+ if (*p == 'h' || *p == 'l') {
+ length_modifier = *p; p++;
+ if (length_modifier == 'l' && *p == 'l') { /* double l = long long */
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+ length_modifier = '2'; /* double l encoded as '2' */
+#else
+ length_modifier = 'l'; /* treat it as a single 'l' */
+#endif
+ p++;
+ }
+ }
+ fmt_spec = *p;
+ /* common synonyms: */
+ switch (fmt_spec) {
+ case 'i': fmt_spec = 'd'; break;
+ case 'D': fmt_spec = 'd'; length_modifier = 'l'; break;
+ case 'U': fmt_spec = 'u'; length_modifier = 'l'; break;
+ case 'O': fmt_spec = 'o'; length_modifier = 'l'; break;
+ default: break;
+ }
+ /* get parameter value, do initial processing */
+ switch (fmt_spec) {
+ case '%': /* % behaves similar to 's' regarding flags and field widths */
+ case 'c': /* c behaves similar to 's' regarding flags and field widths */
+ case 's':
+ length_modifier = '\0'; /* wint_t and wchar_t not supported */
+ /* the result of zero padding flag with non-numeric conversion specifier*/
+ /* is undefined. Solaris and HPUX 10 does zero padding in this case, */
+ /* Digital Unix and Linux does not. */
+#if !defined(SOLARIS_COMPATIBLE) && !defined(HPUX_COMPATIBLE)
+ zero_padding = 0; /* turn zero padding off for string conversions */
+#endif
+ str_arg_l = 1;
+ switch (fmt_spec) {
+ case '%':
+ str_arg = p; break;
+ case 'c': {
+ int j = va_arg(ap, int);
+ uchar_arg = (unsigned char) j; /* standard demands unsigned char */
+ str_arg = (const char *) &uchar_arg;
+ break;
+ }
+ case 's':
+ str_arg = va_arg(ap, const char *);
+ if (!str_arg) str_arg_l = 0;
+ /* make sure not to address string beyond the specified precision !!! */
+ else if (!precision_specified) str_arg_l = strlen(str_arg);
+ /* truncate string if necessary as requested by precision */
+ else if (precision == 0) str_arg_l = 0;
+ else {
+ /* memchr on HP does not like n > 2^31 !!! */
+ const char *q = memchr(str_arg, '\0',
+ precision <= 0x7fffffff ? precision : 0x7fffffff);
+ str_arg_l = !q ? precision : (q-str_arg);
+ }
+ break;
+ default: break;
+ }
+ break;
+ case 'd': case 'u': case 'o': case 'x': case 'X': case 'p': {
+ /* NOTE: the u, o, x, X and p conversion specifiers imply
+ the value is unsigned; d implies a signed value */
+
+ int arg_sign = 0;
+ /* 0 if numeric argument is zero (or if pointer is NULL for 'p'),
+ +1 if greater than zero (or nonzero for unsigned arguments),
+ -1 if negative (unsigned argument is never negative) */
+
+ int int_arg = 0; unsigned int uint_arg = 0;
+ /* only defined for length modifier h, or for no length modifiers */
+
+ long int long_arg = 0; unsigned long int ulong_arg = 0;
+ /* only defined for length modifier l */
+
+ void *ptr_arg = NULL;
+ /* pointer argument value -only defined for p conversion */
+
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+ long long int long_long_arg = 0;
+ unsigned long long int ulong_long_arg = 0;
+ /* only defined for length modifier ll */
+#endif
+ if (fmt_spec == 'p') {
+ /* HPUX 10: An l, h, ll or L before any other conversion character
+ * (other than d, i, u, o, x, or X) is ignored.
+ * Digital Unix:
+ * not specified, but seems to behave as HPUX does.
+ * Solaris: If an h, l, or L appears before any other conversion
+ * specifier (other than d, i, u, o, x, or X), the behavior
+ * is undefined. (Actually %hp converts only 16-bits of address
+ * and %llp treats address as 64-bit data which is incompatible
+ * with (void *) argument on a 32-bit system).
+ */
+#ifdef SOLARIS_COMPATIBLE
+# ifdef SOLARIS_BUG_COMPATIBLE
+ /* keep length modifiers even if it represents 'll' */
+# else
+ if (length_modifier == '2') length_modifier = '\0';
+# endif
+#else
+ length_modifier = '\0';
+#endif
+ ptr_arg = va_arg(ap, void *);
+ if (ptr_arg != NULL) arg_sign = 1;
+ } else if (fmt_spec == 'd') { /* signed */
+ switch (length_modifier) {
+ case '\0':
+ case 'h':
+ /* It is non-portable to specify a second argument of char or short
+ * to va_arg, because arguments seen by the called function
+ * are not char or short. C converts char and short arguments
+ * to int before passing them to a function.
+ */
+ int_arg = va_arg(ap, int);
+ if (int_arg > 0) arg_sign = 1;
+ else if (int_arg < 0) arg_sign = -1;
+ break;
+ case 'l':
+ long_arg = va_arg(ap, long int);
+ if (long_arg > 0) arg_sign = 1;
+ else if (long_arg < 0) arg_sign = -1;
+ break;
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+ case '2':
+ long_long_arg = va_arg(ap, long long int);
+ if (long_long_arg > 0) arg_sign = 1;
+ else if (long_long_arg < 0) arg_sign = -1;
+ break;
+#endif
+ }
+ } else { /* unsigned */
+ switch (length_modifier) {
+ case '\0':
+ case 'h':
+ uint_arg = va_arg(ap, unsigned int);
+ if (uint_arg) arg_sign = 1;
+ break;
+ case 'l':
+ ulong_arg = va_arg(ap, unsigned long int);
+ if (ulong_arg) arg_sign = 1;
+ break;
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+ case '2':
+ ulong_long_arg = va_arg(ap, unsigned long long int);
+ if (ulong_long_arg) arg_sign = 1;
+ break;
+#endif
+ }
+ }
+ str_arg = tmp; str_arg_l = 0;
+ /* NOTE:
+ * For d, i, u, o, x, and X conversions, if precision is specified,
+ * the '0' flag should be ignored. This is so with Solaris 2.6,
+ * Digital UNIX 4.0, HPUX 10, Linux, FreeBSD, NetBSD; but not with Perl.
+ */
+#ifndef PERL_COMPATIBLE
+ if (precision_specified) zero_padding = 0;
+#endif
+ if (fmt_spec == 'd') {
+ if (force_sign && arg_sign >= 0)
+ tmp[str_arg_l++] = space_for_positive ? ' ' : '+';
+ /* leave negative numbers for sprintf to handle,
+ to avoid handling tricky cases like (short int)(-32768) */
+#ifdef LINUX_COMPATIBLE
+ } else if (fmt_spec == 'p' && force_sign && arg_sign > 0) {
+ tmp[str_arg_l++] = space_for_positive ? ' ' : '+';
+#endif
+ } else if (alternate_form) {
+ if (arg_sign != 0 && (fmt_spec == 'x' || fmt_spec == 'X') )
+ { tmp[str_arg_l++] = '0'; tmp[str_arg_l++] = fmt_spec; }
+ /* alternate form should have no effect for p conversion, but ... */
+#ifdef HPUX_COMPATIBLE
+ else if (fmt_spec == 'p'
+ /* HPUX 10: for an alternate form of p conversion,
+ * a nonzero result is prefixed by 0x. */
+#ifndef HPUX_BUG_COMPATIBLE
+ /* Actually it uses 0x prefix even for a zero value. */
+ && arg_sign != 0
+#endif
+ ) { tmp[str_arg_l++] = '0'; tmp[str_arg_l++] = 'x'; }
+#endif
+ }
+ zero_padding_insertion_ind = str_arg_l;
+ if (!precision_specified) precision = 1; /* default precision is 1 */
+ if (precision == 0 && arg_sign == 0
+#if defined(HPUX_BUG_COMPATIBLE) || defined(LINUX_COMPATIBLE)
+ && fmt_spec != 'p'
+ /* HPUX 10 man page claims: With conversion character p the result of
+ * converting a zero value with a precision of zero is a null string.
+ * Actually HP returns all zeroes, and Linux returns "(nil)". */
+#endif
+ ) {
+ /* converted to null string */
+ /* When zero value is formatted with an explicit precision 0,
+ the resulting formatted string is empty (d, i, u, o, x, X, p). */
+ } else {
+ char f[5]; int f_l = 0;
+ f[f_l++] = '%'; /* construct a simple format string for sprintf */
+ if (!length_modifier) { }
+ else if (length_modifier=='2') { f[f_l++] = 'l'; f[f_l++] = 'l'; }
+ else f[f_l++] = length_modifier;
+ f[f_l++] = fmt_spec; f[f_l++] = '\0';
+ if (fmt_spec == 'p') str_arg_l += sprintf(tmp+str_arg_l, f, ptr_arg);
+ else if (fmt_spec == 'd') { /* signed */
+ switch (length_modifier) {
+ case '\0':
+ case 'h': str_arg_l+=sprintf(tmp+str_arg_l, f, int_arg); break;
+ case 'l': str_arg_l+=sprintf(tmp+str_arg_l, f, long_arg); break;
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+ case '2': str_arg_l+=sprintf(tmp+str_arg_l,f,long_long_arg); break;
+#endif
+ }
+ } else { /* unsigned */
+ switch (length_modifier) {
+ case '\0':
+ case 'h': str_arg_l+=sprintf(tmp+str_arg_l, f, uint_arg); break;
+ case 'l': str_arg_l+=sprintf(tmp+str_arg_l, f, ulong_arg); break;
+#ifdef SNPRINTF_LONGLONG_SUPPORT
+ case '2': str_arg_l+=sprintf(tmp+str_arg_l,f,ulong_long_arg);break;
+#endif
+ }
+ }
+ /* include the optional minus sign and possible "0x"
+ in the region before the zero padding insertion point */
+ if (zero_padding_insertion_ind < str_arg_l &&
+ tmp[zero_padding_insertion_ind] == '-') {
+ zero_padding_insertion_ind++;
+ }
+ if (zero_padding_insertion_ind+1 < str_arg_l &&
+ tmp[zero_padding_insertion_ind] == '0' &&
+ (tmp[zero_padding_insertion_ind+1] == 'x' ||
+ tmp[zero_padding_insertion_ind+1] == 'X') ) {
+ zero_padding_insertion_ind += 2;
+ }
+ }
+ { size_t num_of_digits = str_arg_l - zero_padding_insertion_ind;
+ if (alternate_form && fmt_spec == 'o'
+#ifdef HPUX_COMPATIBLE /* ("%#.o",0) -> "" */
+ && (str_arg_l > 0)
+#endif
+#ifdef DIGITAL_UNIX_BUG_COMPATIBLE /* ("%#o",0) -> "00" */
+#else
+ /* unless zero is already the first character */
+ && !(zero_padding_insertion_ind < str_arg_l
+ && tmp[zero_padding_insertion_ind] == '0')
+#endif
+ ) { /* assure leading zero for alternate-form octal numbers */
+ if (!precision_specified || precision < num_of_digits+1) {
+ /* precision is increased to force the first character to be zero,
+ except if a zero value is formatted with an explicit precision
+ of zero */
+ precision = num_of_digits+1; precision_specified = 1;
+ }
+ }
+ /* zero padding to specified precision? */
+ if (num_of_digits < precision)
+ number_of_zeros_to_pad = precision - num_of_digits;
+ }
+ /* zero padding to specified minimal field width? */
+ if (!justify_left && zero_padding) {
+ int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
+ if (n > 0) number_of_zeros_to_pad += n;
+ }
+ break;
+ }
+ default: /* unrecognized conversion specifier, keep format string as-is*/
+ zero_padding = 0; /* turn zero padding off for non-numeric convers. */
+#ifndef DIGITAL_UNIX_COMPATIBLE
+ justify_left = 1; min_field_width = 0; /* reset flags */
+#endif
+#if defined(PERL_COMPATIBLE) || defined(LINUX_COMPATIBLE)
+ /* keep the entire format string unchanged */
+ str_arg = starting_p; str_arg_l = p - starting_p;
+ /* well, not exactly so for Linux, which does something between,
+ * and I don't feel an urge to imitate it: "%+++++hy" -> "%+y" */
+#else
+ /* discard the unrecognized conversion, just keep *
+ * the unrecognized conversion character */
+ str_arg = p; str_arg_l = 0;
+#endif
+ if (*p) str_arg_l++; /* include invalid conversion specifier unchanged
+ if not at end-of-string */
+ break;
+ }
+ if (*p) p++; /* step over the just processed conversion specifier */
+ /* insert padding to the left as requested by min_field_width;
+ this does not include the zero padding in case of numerical conversions*/
+ if (!justify_left) { /* left padding with blank or zero */
+ int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
+ if (n > 0) {
+ if (str_l < str_m) {
+ size_t avail = str_m-str_l;
+ fast_memset(str+str_l, (zero_padding?'0':' '), (n>avail?avail:n));
+ }
+ str_l += n;
+ }
+ }
+ /* zero padding as requested by the precision or by the minimal field width
+ * for numeric conversions required? */
+ if (number_of_zeros_to_pad <= 0) {
+ /* will not copy first part of numeric right now, *
+ * force it to be copied later in its entirety */
+ zero_padding_insertion_ind = 0;
+ } else {
+ /* insert first part of numerics (sign or '0x') before zero padding */
+ int n = zero_padding_insertion_ind;
+ if (n > 0) {
+ if (str_l < str_m) {
+ size_t avail = str_m-str_l;
+ fast_memcpy(str+str_l, str_arg, (n>avail?avail:n));
+ }
+ str_l += n;
+ }
+ /* insert zero padding as requested by the precision or min field width */
+ n = number_of_zeros_to_pad;
+ if (n > 0) {
+ if (str_l < str_m) {
+ size_t avail = str_m-str_l;
+ fast_memset(str+str_l, '0', (n>avail?avail:n));
+ }
+ str_l += n;
+ }
+ }
+ /* insert formatted string
+ * (or as-is conversion specifier for unknown conversions) */
+ { int n = str_arg_l - zero_padding_insertion_ind;
+ if (n > 0) {
+ if (str_l < str_m) {
+ size_t avail = str_m-str_l;
+ fast_memcpy(str+str_l, str_arg+zero_padding_insertion_ind,
+ (n>avail?avail:n));
+ }
+ str_l += n;
+ }
+ }
+ /* insert right padding */
+ if (justify_left) { /* right blank padding to the field width */
+ int n = min_field_width - (str_arg_l+number_of_zeros_to_pad);
+ if (n > 0) {
+ if (str_l < str_m) {
+ size_t avail = str_m-str_l;
+ fast_memset(str+str_l, ' ', (n>avail?avail:n));
+ }
+ str_l += n;
+ }
+ }
+ }
+ }
+#if defined(NEED_SNPRINTF_ONLY)
+ va_end(ap);
+#endif
+ if (str_m > 0) { /* make sure the string is null-terminated
+ even at the expense of overwriting the last character
+ (shouldn't happen, but just in case) */
+ str[str_l <= str_m-1 ? str_l : str_m-1] = '\0';
+ }
+ /* Return the number of characters formatted (excluding trailing null
+ * character), that is, the number of characters that would have been
+ * written to the buffer if it were large enough.
+ *
+ * The value of str_l should be returned, but str_l is of unsigned type
+ * size_t, and snprintf is int, possibly leading to an undetected
+ * integer overflow, resulting in a negative return value, which is illegal.
+ * Both XSH5 and ISO C99 (at least the draft) are silent on this issue.
+ * Should errno be set to EOVERFLOW and EOF returned in this case???
+ */
+ return (int) str_l;
+}
+#endif
+#endif /* ndef HAVE_SNPRINTF */