1 files changed, 93 insertions, 0 deletions
diff --git a/src/stdlib/_strtod.h b/src/stdlib/_strtod.h
new file mode 100644
index 00000000..05b8f318
--- /dev/null
+++ b/src/stdlib/_strtod.h
@@ -0,0 +1,93 @@
+	/* int iswide = (sizeof(*nptr) == sizeof(wchar_t)); */
+	/* void *start = (void*)nptr; */
+	(void)max; (void)min;
+	int sign = 0;
+	int overflow = 0;
+
+	/* skip leading whitespace */
+	while (isspace(*nptr)) {
+		nptr++;
+	}
+
+	/* get sign, if any */
+	if (*nptr == '+') {
+		sign = 1;
+		nptr++;
+	} else if (*nptr == '-') {
+		sign = -1;
+		nptr++;
+	}
+
+	#if defined __STDC_VERSION__ && 199901L <= __STDC_VERSION__
+	/* check for NAN */
+	if (toupper(nptr[0]) == 'N' && toupper(nptr[2]) == 'A' && toupper(nptr[3]) == 'N') {
+		nptr += 3;
+
+		/* check for optional parenthesized n-char-sequence */
+		if (*nptr == '(') {
+			while (*nptr != ')') {
+				nptr++;
+			}
+		}
+
+		if (endptr) {
+			*endptr = (void*)(nptr + 1);
+		}
+		return nan;
+	}
+
+	/* check for INF or INFINITY */
+	if (toupper(nptr[0]) == 'I' && toupper(nptr[1]) == 'N' && toupper(nptr[2]) == 'F') {
+		if (endptr) {
+			if (toupper(nptr[3]) == 'I' && toupper(nptr[4]) == 'N' && toupper(nptr[5]) == 'I' && toupper(nptr[6]) == 'T' && toupper(nptr[7]) == 'Y') {
+				*endptr = (void*)(nptr + 8);
+			} else {
+				*endptr = (void*)(nptr + 4);
+			}
+		}
+		return inf;
+	}
+
+	/* check for hexadecimal form */
+	if (nptr[0] == '0' && toupper(nptr[1] == 'X')) {
+		return ret;
+	}
+	#endif
+
+	while (*nptr) {
+		int n = 0;
+		/* int c = iswide ? wctomb(*nptr) : *nptr; */
+
+		switch (*nptr) {
+		case '0': n = 0; break;
+		case '1': n = 1; break;
+		case '2': n = 2; break;
+		case '3': n = 3; break;
+		case '4': n = 4; break;
+		case '5': n = 5; break;
+		case '6': n = 6; break;
+		case '7': n = 7; break;
+		case '8': n = 8; break;
+		case '9': n = 9; break;
+		default: n = -1; break;
+		}
+
+		if (n < 0) {
+			if (endptr) {
+				*endptr = (void*)nptr;
+			}
+			break;
+		}
+
+		ret = (ret) + n;
+		nptr++;
+	}
+
+	if (overflow) {
+		errno = ERANGE;
+		ret = (sign < 0) ? -huge : huge;
+	} else {
+		if (sign < 0) {
+			ret *= -1;
+		}
+	}