1 files changed, 58 insertions, 0 deletions
diff --git a/lib/numbers.c b/lib/numbers.c
new file mode 100644
index 0000000..8334dd4
--- /dev/null
+++ b/lib/numbers.c
@@ -0,0 +1,58 @@
+#include "numbers.h"
+
+int char_to_number(char *st, int *valid)
+{
+	int whattype = 0, result = 0;
+	
+	*valid = 0;
+	
+	if (*st == '0') {
+		st++;
+		if (*st == 'x') {
+			whattype = 1;
+			st++;
+		} else if (*st) {
+			whattype = 2;
+		} else {
+			*valid = 1;
+			return 0;
+		}
+	}
+	
+	while (*st) {
+		switch (whattype) {
+		case 0:
+			if ((*st < '0') || (*st > '9')) {
+				return 0;
+			}
+			result *= 10;
+			result += *st - '0';
+			break;
+		case 1:
+			if (((*st < '0') || (*st > '9')) && ((*st < 'A') || (*st > 'F'))
+			    && ((*st < 'a') || (*st > 'f'))) {
+				return 0;
+			}
+			result *= 16;
+			if ((*st >= '0') && (*st <= '9')) {
+				result += *st - '0';
+			} else if ((*st >= 'A') && (*st <= 'F')) {
+				result += *st - 'A' + 10;
+			} else {
+				result += *st - 'a' + 10;
+			}
+			break;
+		case 2:
+			if ((*st < '0') || (*st > '7')) {
+				return 0;
+			}
+			result *= 8;
+			result += *st - '0';
+			break;
+		}
+		st++;
+	}
+	
+	*valid = 1;
+	return result;
+}