1 files changed, 51 insertions, 0 deletions
diff --git a/subprojects/exess/src/read_utils.c b/subprojects/exess/src/read_utils.c
new file mode 100644
index 00000000..823fe97f
--- /dev/null
+++ b/subprojects/exess/src/read_utils.c
@@ -0,0 +1,51 @@
+/*
+  Copyright 2019-2021 David Robillard <d@drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "read_utils.h"
+#include "string_utils.h"
+
+#include "exess/exess.h"
+
+ExessResult
+read_two_digit_number(uint8_t* const    out,
+                      const uint8_t     min_value,
+                      const uint8_t     max_value,
+                      const char* const str)
+{
+  size_t i = 0;
+
+  // Read digits
+  size_t d = 0;
+  for (; d < 2; ++d, ++i) {
+    if (is_digit(str[i])) {
+      *out = (uint8_t)((*out * 10) + (str[i] - '0'));
+    } else {
+      break;
+    }
+  }
+
+  // Ensure there are exactly the expected number of digits
+  if (d != 2) {
+    return result(EXESS_EXPECTED_DIGIT, i);
+  }
+
+  // Ensure value is in range
+  if (*out < min_value || *out > max_value) {
+    return result(EXESS_OUT_OF_RANGE, i);
+  }
+
+  return result(EXESS_SUCCESS, i);
+}