feat: add tool for noncanonical input

fairmq/tools/IO.h

@@ -0,0 +1,49 @@
+/********************************************************************************
+ *    Copyright (C) 2021 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH    *
+ *                                                                              *
+ *              This software is distributed under the terms of the             *
+ *              GNU Lesser General Public Licence (LGPL) version 3,             *
+ *                  copied verbatim in the file "LICENSE"                       *
+ ********************************************************************************/
+
+#ifndef FAIR_MQ_TOOLS_IO_H
+#define FAIR_MQ_TOOLS_IO_H
+
+#include <termios.h>
+#include <unistd.h>
+
+namespace fair::mq::tools
+{
+
+/// Enables noncanonical mode for the input terminal for the lifetime of this object.
+/// (input becomes available to the application without user having to type a line-delimiter)
+/// Read `man termios` for more details
+struct NonCanonicalInput
+{
+    NonCanonicalInput()
+    {
+        termios t;
+        tcgetattr(STDIN_FILENO, &t); // get the current terminal I/O structure
+        t.c_lflag &= ~ICANON; // disable canonical input
+        t.c_lflag &= ~ECHO; // do not echo input chars
+        tcsetattr(STDIN_FILENO, TCSANOW, &t); // apply the new settings
+    }
+
+    NonCanonicalInput(const NonCanonicalInput&) = delete;
+    NonCanonicalInput(NonCanonicalInput&&) = delete;
+    NonCanonicalInput& operator=(const NonCanonicalInput&) = delete;
+    NonCanonicalInput& operator=(NonCanonicalInput&&) = delete;
+
+    ~NonCanonicalInput()
+    {
+        termios t;
+        tcgetattr(STDIN_FILENO, &t); // get the current terminal I/O structure
+        t.c_lflag |= ICANON; // re-enable canonical input
+        t.c_lflag |= ECHO; // echo input chars
+        tcsetattr(STDIN_FILENO, TCSANOW, &t); // apply the new settings
+    }
+};
+
+} // namespace fair::mq::tools
+
+#endif /* FAIR_MQ_TOOLS_IO_H */