Add str_isallnum_hex

To check if string contains only `[0-9a-zA-Z]`.

src/base/system.cpp

@@ -3430,6 +3430,17 @@ int str_isallnum(const char *str)
 	return 1;
 }
 
+int str_isallnum_hex(const char *str)
+{
+	while(*str)
+	{
+		if(!(*str >= '0' && *str <= '9') && !(*str >= 'a' && *str <= 'f') && !(*str >= 'A' && *str <= 'F'))
+			return 0;
+		str++;
+	}
+	return 1;
+}
+
 int str_toint(const char *str)
 {
 	return str_toint_base(str, 10);

src/base/system.h

@@ -2186,7 +2186,11 @@ float str_tofloat(const char *str);
 int str_isspace(char c);
 
 char str_uppercase(char c);
+
 int str_isallnum(const char *str);
+
+int str_isallnum_hex(const char *str);
+
 unsigned str_quickhash(const char *str);
 
 enum