summaryrefslogtreecommitdiffstats
path: root/Modules/readline.c
blob: aef51ca97734715b7958d9a080392286c426f98c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
/* This module makes GNU readline available to Python.  It has ideas
 * contributed by Lee Busby, LLNL, and William Magro, Cornell Theory
 * Center.  The completer interface was inspired by Lele Gaifax.
 *
 * More recently, it was largely rewritten by Guido van Rossum who is
 * now maintaining it.
 */

/* Standard definitions */
#include "Python.h"
#include <setjmp.h>
#include <signal.h>
#include <errno.h>

/* GNU readline definitions */
#include <readline/readline.h> /* You may need to add an -I option to Setup */

/* Pointers needed from outside (but not declared in a header file). */
extern int (*PyOS_InputHook)();
extern char *(*PyOS_ReadlineFunctionPointer) Py_PROTO((char *));


/* Exported function to send one line to readline's init file parser */

static PyObject *
parse_and_bind(self, args)
	PyObject *self;
	PyObject *args;
{
	char *s;
	if (!PyArg_ParseTuple(args, "s", &s))
		return NULL;
	rl_parse_and_bind(s);
	Py_INCREF(Py_None);
	return Py_None;
}

static char doc_parse_and_bind[] = "\
parse_and_bind(string) -> None\n\
Parse and execute single line of a readline init file.\
";


/* Exported function to parse a readline init file */

static PyObject *
read_init_file(self, args)
	PyObject *self;
	PyObject *args;
{
	char *s = NULL;
	if (!PyArg_ParseTuple(args, "|z", &s))
		return NULL;
	errno = rl_read_init_file(s);
	if (errno)
		return PyErr_SetFromErrno(PyExc_IOError);
	Py_INCREF(Py_None);
	return Py_None;
}

static char doc_read_init_file[] = "\
read_init_file([filename]) -> None\n\
Parse a readline initialization file.\n\
The default filename is the last filename used.\
";


/* Exported function to specify a word completer in Python */

static PyObject *completer = NULL;
static PyThreadState *tstate = NULL;

static PyObject *
set_completer(self, args)
	PyObject *self;
	PyObject *args;
{
	PyObject *function = Py_None;
	if (!PyArg_ParseTuple(args, "|O", &function))
		return NULL;
	if (function == Py_None) {
		Py_XDECREF(completer);
		completer = NULL;
		tstate = NULL;
	}
	else if (PyCallable_Check(function)) {
		PyObject *tmp = completer;
		Py_INCREF(function);
		completer = function;
		Py_XDECREF(tmp);
		tstate = PyThreadState_Get();
	}
	else {
		PyErr_SetString(PyExc_TypeError,
				"set_completer(func): argument not callable");
		return NULL;
	}
	Py_INCREF(Py_None);
	return Py_None;
}

static char doc_set_completer[] = "\
set_completer([function]) -> None\n\
Set or remove the completer function.\n\
The function is called as function(text, state),\n\
for i in [0, 1, 2, ...] until it returns a non-string.\n\
It should return the next possible completion starting with 'text'.\
";


/* Table of functions exported by the module */

static struct PyMethodDef readline_methods[] =
{
	{"parse_and_bind", parse_and_bind, 1, doc_parse_and_bind},
	{"read_init_file", read_init_file, 1, doc_read_init_file},
	{"set_completer", set_completer, 1, doc_set_completer},
	{0, 0}
};

/* C function to call the Python completer. */

static char *
on_completion(text, state)
	char *text;
	int state;
{
	char *result = NULL;
	if (completer != NULL) {
		PyObject *r;
		/* Note that readline is called with the interpreter
		   lock released! */
		PyEval_RestoreThread(tstate);
		r = PyObject_CallFunction(completer, "si", text, state);
		if (r == NULL)
			goto error;
		if (r == Py_None) {
			result = NULL;
		}
		else {
			char *s = PyString_AsString(r);
			if (s == NULL)
				goto error;
			result = strdup(s);
		}
		Py_DECREF(r);
		goto done;
	  error:
		PyErr_Clear();
		Py_XDECREF(r);
	  done:
		PyEval_SaveThread();
	}
	return result;
}


/* Helper to initialize GNU readline properly. */

static void
setup_readline()
{
	rl_readline_name = "python";
	/* Force rebind of TAB to insert-tab */
	rl_bind_key('\t', rl_insert);
	/* Bind both ESC-TAB and ESC-ESC to the completion function */
	rl_bind_key_in_map ('\t', rl_complete, emacs_meta_keymap);
	rl_bind_key_in_map ('\033', rl_complete, emacs_meta_keymap);
	/* Set our completion function */
	rl_completion_entry_function = (Function *) on_completion;
	/* Set Python word break characters */
	rl_completer_word_break_characters =
		" \t\n`~!@#$%^&*()-=+[{]}\\|;:'\",<>/?";
		/* All nonalphanums except '.' */
	/* Initialize (allows .inputrc to override) */
	rl_initialize();
}


/* Interrupt handler */

static jmp_buf jbuf;

/* ARGSUSED */
static RETSIGTYPE
onintr(sig)
	int sig;
{
	longjmp(jbuf, 1);
}


/* Wrapper around GNU readline that handles signals differently. */

static char *
call_readline(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 = PyOS_InputHook;
	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;
}


/* Initialize the module */

static char doc_module[] =
"Importing this module enables command line editing using GNU readline.";

void
initreadline()
{
	PyObject *m;

	m = Py_InitModule4("readline", readline_methods, doc_module,
			   (PyObject *)NULL, PYTHON_API_VERSION);
	if (isatty(fileno(stdin))) {
		PyOS_ReadlineFunctionPointer = call_readline;
		setup_readline();
	}
}