From 0969d362751bd779fc6618d70ddd6c76e8cbc12c Mon Sep 17 00:00:00 2001
From: Guido van Rossum <guido@python.org>
Date: Tue, 5 Aug 1997 21:27:50 +0000
Subject: [PATCH] New mechanism for GNU readline interface, via module

---
 Modules/Setup.in   |  10 ++++
 Modules/_tkinter.c |  12 ++---
 Modules/readline.c | 122 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 135 insertions(+), 9 deletions(-)
 create mode 100644 Modules/readline.c

diff --git a/Modules/Setup.in b/Modules/Setup.in
index 6acfa885e62..bb06b11ab7a 100644
--- a/Modules/Setup.in
+++ b/Modules/Setup.in
@@ -120,6 +120,16 @@ signal signalmodule.c		# signal(2)
 
 #*shared*
 
+# GNU readline.  Unlike previous Python incarnations, GNU readline is
+# now incorporated in an optional module, configured in the Setup file
+# instead of by a configure script switch.  You may have to insert a
+# -L option pointing to the directory where libreadline.* lives,
+# and you may have to change -ltermcap to -ltermlib or perhaps remove
+# it, depending on your system -- see the GNU readline instructions.
+# It's okay for this to be a shared library, too.
+
+#readline readline.c -lreadline -ltermcap
+
 
 # Modules that should always be present (non UNIX dependent):
 
diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index 528c2296a81..1f32c4a492f 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -1428,11 +1428,9 @@ static PyMethodDef moduleMethods[] =
 	{NULL,                 NULL}
 };
 
-#ifdef WITH_READLINE
 static int
 EventHook()
 {
-	/* XXX Reset tty */
 	if (errorInCmd) {
 		errorInCmd = 0;
 		PyErr_Restore(excInCmd, valInCmd, trbInCmd);
@@ -1443,7 +1441,6 @@ EventHook()
 		Tcl_DoOneEvent(TCL_DONT_WAIT);
 	return 0;
 }
-#endif /* WITH_READLINE */
 
 
 /* all errors will be checked in one fell swoop in init_tkinter() */
@@ -1476,9 +1473,7 @@ ins_string(d, name, val)
 void
 init_tkinter()
 {
-#ifdef WITH_READLINE
-	extern int (*rl_event_hook) ();
-#endif /* WITH_READLINE */
+	extern int (*Py_input_hook) ();
 	PyObject *m, *d;
 
 	Tkapp_Type.ob_type = &PyType_Type;
@@ -1502,9 +1497,8 @@ init_tkinter()
 	ins_string(d, "TK_VERSION", TK_VERSION);
 	ins_string(d, "TCL_VERSION", TCL_VERSION);
 
-#ifdef WITH_READLINE
-	rl_event_hook = EventHook;
-#endif /* WITH_READLINE */
+	if (Py_input_hook == NULL)
+		Py_input_hook = EventHook;
 
 	if (PyErr_Occurred())
 		Py_FatalError("can't initialize module _tkinter");
diff --git a/Modules/readline.c b/Modules/readline.c
new file mode 100644
index 00000000000..8927630eb0b
--- /dev/null
+++ b/Modules/readline.c
@@ -0,0 +1,122 @@
+/* The readline module makes GNU readline available to Python.  It
+ * has ideas contributed by Lee Busby, LLNL, and William Magro,
+ * Cornell Theory Center.
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "Python.h"
+#include <setjmp.h>
+#include <signal.h>
+
+/* Routines needed from outside (but not declared in a header file). */
+extern int (*Py_input_hook)();
+extern char *readline();
+extern int rl_initialize();
+extern int rl_insert();
+extern int rl_bind_key();
+extern void add_history();
+extern char *rl_readline_name;
+extern int (*rl_event_hook)();
+extern char *(*PyOS_ReadlineFunctionPointer) Py_PROTO((char *));
+
+/* This module's initialization routine */
+void initreadline (void);
+
+static void PyOS_ReadlineInit();
+static RETSIGTYPE onintr();
+static char *PyOS_GnuReadline();
+static jmp_buf jbuf;
+static PyObject *ReadlineError;
+static int already_initialized = 0;
+static char readline_module_documentation[] =
+"Readline Module, version0.0"
+;
+
+static struct PyMethodDef readline_methods[] =
+{ 
+  { 0, 0 }
+};
+
+/* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% */
+
+/* Initialize the module.  Actually, that's all you can or need to do. */
+void initreadline (void)
+{
+  PyObject *m, *d;
+
+  if (already_initialized)
+    return;
+  m = Py_InitModule4 ("readline", readline_methods,
+		      readline_module_documentation,
+		      (PyObject *) 0, PYTHON_API_VERSION);
+  d = PyModule_GetDict (m);
+  ReadlineError = PyString_FromString ("Readline.error");
+  PyDict_SetItemString (d, "error", ReadlineError);
+  if (PyErr_Occurred ()) {
+    Py_FatalError ("Cannot initialize module readline");
+  }
+  if (isatty(fileno(stdin))){
+    PyOS_ReadlineFunctionPointer = PyOS_GnuReadline;
+    PyOS_ReadlineInit();
+  }
+  already_initialized = 1;
+}
+
+/* ARGSUSED */
+static RETSIGTYPE
+onintr(sig)
+  int sig;
+{
+  longjmp(jbuf, 1);
+}
+
+static void
+PyOS_ReadlineInit()
+{
+    /* Force rebind of TAB to insert-tab */
+    rl_readline_name = "python";
+    rl_initialize();
+    rl_bind_key('\t', rl_insert);
+}
+
+static char *
+PyOS_GnuReadline(prompt)
+	char *prompt;
+{
+	int n;
+	char *p;
+	RETSIGTYPE (*old_inthandler)();
+	old_inthandler = signal(SIGINT, onintr);
+	if (setjmp(jbuf)) {
+#ifdef HAVE_SIGRELSE
+		/* This seems necessary on SunOS 4.1 (Rasmus Hahn) */
+		sigrelse(SIGINT);
+#endif
+		signal(SIGINT, old_inthandler);
+		return NULL;
+	}
+	rl_event_hook = Py_input_hook;
+	p = readline(prompt);
+	signal(SIGINT, old_inthandler);
+	if (p == NULL) {
+		p = malloc(1);
+		if (p != NULL)
+			*p = '\0';
+		return p;
+	}
+	n = strlen(p);
+	if (n > 0)
+		add_history(p);
+	if ((p = realloc(p, n+2)) != NULL) {
+		p[n] = '\n';
+		p[n+1] = '\0';
+	}
+	return p;
+}
+
+#ifdef __cplusplus
+}
+#endif