From 642b5fb0007b64c77d186fcb018d571152ee1d47 Mon Sep 17 00:00:00 2001
From: dzwdz
Date: Mon, 14 Aug 2023 18:51:07 +0200
Subject: reorganization: first steps

---
 src/cmd/init/driver/termcook.c | 103 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 103 insertions(+)
 create mode 100644 src/cmd/init/driver/termcook.c

(limited to 'src/cmd/init/driver/termcook.c')

diff --git a/src/cmd/init/driver/termcook.c b/src/cmd/init/driver/termcook.c
new file mode 100644
index 0000000..a76f3a8
--- /dev/null
+++ b/src/cmd/init/driver/termcook.c
@@ -0,0 +1,103 @@
+#include "driver.h"
+#include <camellia/syscalls.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+enum tstate {
+	Normal,
+	Esc,
+	CSI,
+};
+
+static void w_output(hid_t output, const char *buf, size_t len) {
+	size_t pos = 0;
+	while (pos < len) {
+		int ret = _sys_write(output, buf + pos, len - pos, pos, 0);
+		if (ret < 0) break;
+		pos += ret;
+	}
+}
+
+static void line_editor(hid_t input, hid_t output) {
+	char readbuf[16], linebuf[256];
+	size_t linepos = 0;
+	enum tstate state = Normal;
+	for (;;) {
+		int readlen = _sys_read(input, readbuf, sizeof readbuf, -1);
+		if (readlen < 0) return;
+		for (int i = 0; i < readlen; i++) {
+			char c = readbuf[i];
+			switch (state) {
+			case Normal:
+				switch (c) {
+				case '\b':
+				case 0x7f:
+					if (linepos != 0) {
+						printf("\b \b");
+						linepos--;
+					}
+					break;
+				case 3: /* C-c */
+					_sys_exit(1);
+				case 4: /* EOT, C-d */
+					if (linepos > 0) {
+						w_output(output, linebuf, linepos);
+						linepos = 0;
+					} else {
+						_sys_write(output, NULL, 0, 0, 0); /* EOF */
+					}
+					break;
+				case '\n':
+				case '\r':
+					printf("\n");
+					if (linepos < sizeof linebuf)
+						linebuf[linepos++] = '\n';
+					w_output(output, linebuf, linepos);
+					linepos = 0;
+					break;
+				case '\e':
+					state = Esc;
+					break;
+				case '\t':
+					break;
+				default:
+					if (linepos < sizeof linebuf) {
+						linebuf[linepos++] = c;
+						printf("%c", c);
+					}
+					break;
+				}
+				break;
+			case Esc:
+				if (c == '[') state = CSI;
+				else state = Normal;
+				break;
+			case CSI:
+				if (0x40 <= c && c <= 0x7E) state = Normal;
+				break;
+			}
+		}
+	}
+}
+
+void termcook(void) {
+	hid_t stdin_pipe[2] = {-1, -1};
+	if (_sys_pipe(stdin_pipe, 0) < 0)
+		return;
+
+	if (!fork()) {
+		/* the caller continues in a child process,
+		 * so it can be killed when the line editor quits */
+		_sys_dup(stdin_pipe[0], 0, 0);
+		close(stdin_pipe[0]);
+		close(stdin_pipe[1]);
+		return;
+	}
+	if (!fork()) {
+		close(stdin_pipe[0]);
+		line_editor(0, stdin_pipe[1]);
+		exit(0);
+	}
+	exit(_sys_await());
+}
-- 
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