From 4b49b1d0cc23f909d1be89cf8f816f820b343e0a Mon Sep 17 00:00:00 2001
From: Benjamin Barenblat <bbarenblat@gmail.com>
Date: Sun, 26 Dec 2021 13:53:22 -0500
Subject: Don’t hard-code escape sequences
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Instead of hard-coding VT100-compatible escape sequences, parse the
system terminfo database and read escape sequences from it. This is
both more flexible (it should work well on more terminals) and more
efficient (it won’t insert padding on terminals that don’t need it).
---
 goldfishterm/simple.cc | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 goldfishterm/simple.cc

(limited to 'goldfishterm/simple.cc')

diff --git a/goldfishterm/simple.cc b/goldfishterm/simple.cc
new file mode 100644
index 0000000..9c4c9a9
--- /dev/null
+++ b/goldfishterm/simple.cc
@@ -0,0 +1,74 @@
+// Copyright 2021 Benjamin Barenblat
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not
+// use this file except in compliance with the License. You may obtain a copy of
+// the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations under
+// the License.
+
+#include "goldfishterm/simple.h"
+
+#include <stdlib.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include <stdexcept>
+#include <vector>
+
+#include "goldfishterm/internal/emit.h"
+#include "goldfishterm/terminfo.h"
+#include "third_party/abseil/absl/strings/string_view.h"
+
+namespace goldfishterm {
+
+namespace {
+
+using ::goldfishterm_internal::InterpretStringCapability;
+using ::goldfishterm_internal::InterpretStringCapabilityInput;
+
+termios StdoutTermios() {
+  termios tty;
+  if (tcgetattr(STDOUT_FILENO, &tty) < 0) {
+    throw std::system_error(errno, std::system_category(), "tcgetattr");
+  }
+  return tty;
+}
+
+absl::string_view TerminalNameFromEnvironment() {
+  const char* name = getenv("TERM");
+  if (name == nullptr) {
+    throw std::runtime_error("TERM unset");
+  }
+  return name;
+}
+
+}  // namespace
+
+SimpleTerminalOutput::SimpleTerminalOutput()
+    : SimpleTerminalOutput(StdoutTermios()) {}
+
+SimpleTerminalOutput::SimpleTerminalOutput(const termios& tty)
+    : terminfo_(
+          TerminfoEntry::FromSystemDatabase(TerminalNameFromEnvironment())) {
+  baud_ = cfgetospeed(&tty);
+}
+
+void SimpleTerminalOutput::Emit(
+    StringCapability cap,
+    std::vector<goldfishterm_internal::StringCapabilityParameter> parameters) {
+  goldfishterm_internal::Emit(
+      InterpretStringCapability(
+          InterpretStringCapabilityInput(terminfo_, terminfo_.get(cap).value(),
+                                         std::move(parameters), /*baud=*/baud_,
+                                         /*lines_affected=*/1))
+          .terms,
+      std::cout);
+}
+
+}  // namespace goldfishterm
-- 
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