From 83fa0a85281118103b4f8bf82dcb25cacb42d982 Mon Sep 17 00:00:00 2001
From: _ov4 <ov4@ov4.org>
Date: Mon, 21 Sep 2026 10:54:49 +0000
Subject: add raw mode

---
 include/line/mode.h      | 59 ++++++++++++++++++++++++++++++++++++++++++++++++
 module-test/line_test.cc | 33 +++++++++++++++++++++++++++
 2 files changed, 92 insertions(+)
 create mode 100644 include/line/mode.h
 create mode 100644 module-test/line_test.cc

diff --git a/include/line/mode.h b/include/line/mode.h
new file mode 100644
index 0000000..8811e66
--- /dev/null
+++ b/include/line/mode.h
@@ -0,0 +1,59 @@
+#pragma once
+
+#include <unistd.h>
+#include <termios.h>
+#include <stdlib.h>
+
+using namespace std; // TODO: remove
+
+namespace ov4
+{
+
+inline termios attr;
+
+void disable_raw()
+{
+    tcsetattr(STDIN_FILENO, TCSAFLUSH, &attr);
+}
+
+void enable_raw()
+{
+    termios attr_raw;
+    tcgetattr(STDIN_FILENO, &attr);
+    tcgetattr(STDIN_FILENO, &attr_raw);
+
+    // LOCAL
+
+    // disable
+    // echo
+    // canonical
+    // signal
+    // disable post-input processing, aka control-V
+    attr_raw.c_lflag &= ~(ECHO | ICANON | ISIG | IEXTEN);
+
+    // INPUT
+
+    // disable 
+    // software flow control, aka control-S/Q
+    // \n and \r conversion
+    attr_raw.c_iflag &= ~(IXON | ICRNL);
+
+    // OUTPUT
+
+    // disable
+    // post-output processing
+    attr_raw.c_oflag &= ~(OPOST);
+
+    // misc
+    attr_raw.c_iflag &= ~(BRKINT | INPCK | ISTRIP);
+    attr_raw.c_cflag |= ~(CS8);
+
+    atexit(disable_raw);
+
+    // TCSAFLUSH
+    // the change shall occur after all output written to fildes is transmitted
+    // and all input so far received but not read shall be discarded before the change is made
+    tcsetattr(STDIN_FILENO, TCSAFLUSH, &attr_raw);
+}
+
+}
diff --git a/module-test/line_test.cc b/module-test/line_test.cc
new file mode 100644
index 0000000..7bc16df
--- /dev/null
+++ b/module-test/line_test.cc
@@ -0,0 +1,33 @@
+/*
+ * test line editor
+   $ g++ \
+   module-test/line_test.cc \
+   -std=c++26 -Iinclude -Ithird_party/magic_enum/include \
+   -O0 -ggdb3 -fno-omit-frame-pointer -fno-inline -D_GLIBCXX_ASSERTIONS \
+   -o module-test/line_test.out
+ *
+ */
+
+
+#include <iostream>
+#include <print>
+
+#include "line/mode.h"
+
+using namespace std;
+using namespace ov4;
+
+int main()
+{
+    enable_raw();
+    char c;
+    while (read(STDIN_FILENO, &c, 1) == 1)
+    {
+        if (c == 'q') break;
+        if (iscntrl(c))
+            print("control: {}\r\n", static_cast<unsigned char>(c));
+        else
+            print("entered: {}\r\n", c);
+    }
+    return 0;
+}
-- 
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