tb Hex/byte escapes

ulib/ulib.h

@@ -4,6 +4,7 @@
 #include <ansiq/all.h>
 #include <args/args.h>
 #include <string/string.h>
+#include <string/conv.h>
 #include <string/char.h>
 #include <sync/spinlock.h>
 #include <syscall/syscall.h>

user/tb/interp.c

@@ -45,6 +45,20 @@ void tz_tokenize(Tokenizer *tz) {
               case '\\':  c = '\\'; break;
               case '\'':  c = '\''; break;
               case '"':   c = '"'; break;
+              case 'x': {
+                if (i + 2 < len) {
+                  char buf[3];
+                  buf[0] = tz->str[i + 1];
+                  buf[1] = tz->str[i + 2];
+                  buf[2] = '\0';
+
+                  char *endp;
+                  uint8_t b = (uint8_t)string_conv_strtoul(buf, &endp, 16);
+                  c = *(char *)&b;
+
+                  i += 2;
+                }
+              } break;
               default:    c = tz->str[i]; break;
             }
             if (j + 1 < TZ_MAX_TK) {