Copied from arch/arm32/arm32/strtoul.c,v

sys/lib/libkern/strtoul.c

@@ -0,0 +1,86 @@
+/*	$NetBSD: strtoul.c,v 1.4 1999/11/29 22:51:19 simonb Exp $	*/
+
+#include <sys/param.h>
+#include <lib/libkern/libkern.h>
+
+#ifndef ULONG_MAX
+#define	ULONG_MAX	((u_long)(~0L))		/* 0xFFFFFFFF */
+#endif
+
+u_long
+strtoul(s, ptr, base)
+	const char *s;
+	char **ptr;
+	int base;
+{
+	u_long total = 0;
+	u_int digit;
+	const char *start=s;
+	int did_conversion=0;
+	int overflow = 0;
+	int negate = 0;
+	u_long maxdiv, maxrem;
+
+	if (s == NULL) {
+		if (!ptr)
+			*ptr = (char *)start;
+		return 0L;
+	}
+
+	while (*s == ' ')
+		s++;
+	if (*s == '+')
+		s++;
+	else if (*s == '-')
+		s++, negate = 1;
+	if (base==0 || base==16) { /*  the 'base==16' is for handling 0x */
+		int tmp;
+
+      /*
+       * try to infer base from the string
+       */
+		if (*s != '0')
+			tmp = 10;	/* doesn't start with 0 - assume decimal */
+		else if (s[1] == 'X' || s[1] == 'x')
+			tmp = 16, s += 2; /* starts with 0x or 0X - hence hex */
+		else
+			tmp = 8;	/* starts with 0 - hence octal */
+		if (base==0)
+			base = (int)tmp;
+	}
+
+	maxdiv = ULONG_MAX / base;
+	maxrem = ULONG_MAX % base;
+
+	while ((digit = *s) != '\0') {
+		if (digit >= '0' && digit < ('0' + min(base, 10)))
+			digit -= '0';
+		else
+			if (base > 10) {
+				if (digit >= 'a' && digit < ('a'+(base-10)))
+					digit = digit - 'a' + 10;
+				else if (digit >= 'A' && digit < ('A'+(base-10)))
+					digit = digit - 'A' + 10;
+				else
+					break;
+			}
+			else
+				break;
+			did_conversion = 1;
+			if (total > maxdiv
+			    || (total == maxdiv && digit > maxrem))
+				overflow = 1;
+			total = (total * base) + digit;
+			s++;
+	}
+	if (overflow) {
+		if (ptr != NULL)
+			*ptr = (char *)s;
+		return (ULONG_MAX);
+	}
+	if (ptr != NULL)
+		*ptr = (char *) ((did_conversion) ? (char *)s : (char *)start);
+	return negate ? -total : total;
+}
+
+/* End of strtoul.c */