summaryrefslogtreecommitdiffstats
path: root/Modules/readline.c
blob: ed78b9224768ab68b54f0868e1d6d0ee13fba3fd (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
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
/* 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 */
#undef HAVE_CONFIG_H /* Else readline/chardefs.h includes strings.h */
#include <readline/readline.h>
#include <readline/history.h>

#ifdef HAVE_RL_COMPLETION_MATCHES
#define completion_matches(x, y) rl_completion_matches((x), ((rl_compentry_func_t *)(y)))
#endif

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


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

static PyObject *
parse_and_bind(PyObject *self, PyObject *args)
{
	char *s, *copy;
	if (!PyArg_ParseTuple(args, "s:parse_and_bind", &s))
		return NULL;
	/* Make a copy -- rl_parse_and_bind() modifies its argument */
	/* Bernard Herzog */
	copy = malloc(1 + strlen(s));
	if (copy == NULL)
		return PyErr_NoMemory();
	strcpy(copy, s);
	rl_parse_and_bind(copy);
	free(copy); /* Free the copy */
	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(PyObject *self, PyObject *args)
{
	char *s = NULL;
	if (!PyArg_ParseTuple(args, "|z:read_init_file", &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 load a readline history file */

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

static int history_length = -1; /* do not truncate history by default */
static char doc_read_history_file[] = "\
read_history_file([filename]) -> None\n\
Load a readline history file.\n\
The default filename is ~/.history.\
";


/* Exported function to save a readline history file */

static PyObject *
write_history_file(PyObject *self, PyObject *args)
{
	char *s = NULL;
	if (!PyArg_ParseTuple(args, "|z:write_history_file", &s))
		return NULL;
	errno = write_history(s);
	if (!errno && history_length >= 0)
		history_truncate_file(s, history_length);
	if (errno)
		return PyErr_SetFromErrno(PyExc_IOError);
	Py_INCREF(Py_None);
	return Py_None;
}

static char doc_write_history_file[] = "\
write_history_file([filename]) -> None\n\
Save a readline history file.\n\
The default filename is ~/.history.\
";


static char set_history_length_doc[] = "\
set_history_length(length) -> None\n\
set the maximal number of items which will be written to\n\
the history file. A negative length is used to inhibit\n\
history truncation.\n\
";

static PyObject*
set_history_length(PyObject *self, PyObject *args)
{
    int length = history_length;
    if (!PyArg_ParseTuple(args, "i:set_history_length", &length))
	return NULL;
    history_length = length;
    Py_INCREF(Py_None);
    return Py_None;
}



static char get_history_length_doc[] = "\
get_history_length() -> int\n\
return the maximum number of items that will be written to\n\
the history file.\n\
";

static PyObject*
get_history_length(PyObject *self, PyObject *args)
{
	if (!PyArg_ParseTuple(args, ":get_history_length"))
		return NULL;
	return Py_BuildValue("i", history_length);
}

/* Generic hook function setter */

static PyObject *
set_hook(const char * funcname, PyObject **hook_var, PyThreadState **tstate, PyObject *args)
{
	PyObject *function = Py_None;
	char buf[80];
	PyOS_snprintf(buf, sizeof(buf), "|O:set_%.50s", funcname);
	if (!PyArg_ParseTuple(args, buf, &function))
		return NULL;
	if (function == Py_None) {
		Py_XDECREF(*hook_var);
		*hook_var = NULL;
		*tstate = NULL;
	}
	else if (PyCallable_Check(function)) {
		PyObject *tmp = *hook_var;
		Py_INCREF(function);
		*hook_var = function;
		Py_XDECREF(tmp);
		*tstate = PyThreadState_Get();
	}
	else {
		PyOS_snprintf(buf, sizeof(buf),
			      "set_%.50s(func): argument not callable",
			      funcname);
		PyErr_SetString(PyExc_TypeError, buf);
		return NULL;
	}
	Py_INCREF(Py_None);
	return Py_None;
}

/* Exported functions to specify hook functions in Python */

static PyObject *startup_hook = NULL;
static PyThreadState *startup_hook_tstate = NULL;

#ifdef HAVE_RL_PRE_INPUT_HOOK
static PyObject *pre_input_hook = NULL;
static PyThreadState *pre_input_hook_tstate = NULL;
#endif

static PyObject *
set_startup_hook(PyObject *self, PyObject *args)
{
	return set_hook("startup_hook", &startup_hook, &startup_hook_tstate, args);
}

static char doc_set_startup_hook[] = "\
set_startup_hook([function]) -> None\n\
Set or remove the startup_hook function.\n\
The function is called with no arguments just\n\
before readline prints the first prompt.\n\
";

#ifdef HAVE_RL_PRE_INPUT_HOOK
static PyObject *
set_pre_input_hook(PyObject *self, PyObject *args)
{
	return set_hook("pre_input_hook", &pre_input_hook,  &pre_input_hook_tstate, args);
}

static char doc_set_pre_input_hook[] = "\
set_pre_input_hook([function]) -> None\n\
Set or remove the pre_input_hook function.\n\
The function is called with no arguments after the first prompt\n\
has been printed and just before readline starts reading input\n\
characters.\n\
";
#endif

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

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

static PyObject *begidx = NULL;
static PyObject *endidx = NULL;

/* get the beginning index for the scope of the tab-completion */
static PyObject *
get_begidx(PyObject *self)
{
	Py_INCREF(begidx);
	return begidx;
}

static char doc_get_begidx[] = "\
get_begidx() -> int\n\
get the beginning index of the readline tab-completion scope";

/* get the ending index for the scope of the tab-completion */
static PyObject *
get_endidx(PyObject *self)
{
	Py_INCREF(endidx);
	return endidx;
}

static char doc_get_endidx[] = "\
get_endidx() -> int\n\
get the ending index of the readline tab-completion scope";


/* set the tab-completion word-delimiters that readline uses */

static PyObject *
set_completer_delims(PyObject *self, PyObject *args)
{
	char *break_chars;

	if(!PyArg_ParseTuple(args, "s:set_completer_delims", &break_chars)) {
		return NULL;
	}
	free(rl_completer_word_break_characters);
	rl_completer_word_break_characters = strdup(break_chars);
	Py_INCREF(Py_None);
	return Py_None;
}

static char doc_set_completer_delims[] = "\
set_completer_delims(string) -> None\n\
set the readline word delimiters for tab-completion";

static PyObject *
py_add_history(PyObject *self, PyObject *args)
{
	char *line;

	if(!PyArg_ParseTuple(args, "s:add_history", &line)) {
		return NULL;
	}
	add_history(line);
	Py_INCREF(Py_None);
	return Py_None;
}

static char doc_add_history[] = "\
add_history(string) -> None\n\
add a line to the history buffer";


/* get the tab-completion word-delimiters that readline uses */

static PyObject *
get_completer_delims(PyObject *self)
{
	return PyString_FromString(rl_completer_word_break_characters);
}
	
static char doc_get_completer_delims[] = "\
get_completer_delims() -> string\n\
get the readline word delimiters for tab-completion";

static PyObject *
set_completer(PyObject *self, PyObject *args)
{
	return set_hook("completer", &completer, &completer_tstate, args);
}

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 state in 0, 1, 2, ..., until it returns a non-string.\n\
It should return the next possible completion starting with 'text'.\
";

/* Exported function to get any element of history */

static PyObject *
get_history_item(PyObject *self, PyObject *args)
{
	int idx = 0;
	HIST_ENTRY *hist_ent;

	if (!PyArg_ParseTuple(args, "i:index", &idx))
		return NULL;
	if ((hist_ent = history_get(idx)))
	    return PyString_FromString(hist_ent->line);
	else {
		Py_INCREF(Py_None);
		return Py_None;
	}
}

static char doc_get_history_item[] = "\
get_history_item() -> string\n\
return the current contents of history item at index.\
";

/* Exported function to get current length of history */

static PyObject *
get_current_history_length(PyObject *self)
{
	HISTORY_STATE *hist_st;

	hist_st = history_get_history_state();
	return PyInt_FromLong(hist_st ? (long) hist_st->length : (long) 0);
}

static char doc_get_current_history_length[] = "\
get_current_history_length() -> integer\n\
return the current (not the maximum) length of history.\
";

/* Exported function to read the current line buffer */

static PyObject *
get_line_buffer(PyObject *self)
{
	return PyString_FromString(rl_line_buffer);
}

static char doc_get_line_buffer[] = "\
get_line_buffer() -> string\n\
return the current contents of the line buffer.\
";

/* Exported function to insert text into the line buffer */

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

static char doc_insert_text[] = "\
insert_text(string) -> None\n\
Insert text into the command line.\
";

static PyObject *
redisplay(PyObject *self)
{
	rl_redisplay();
	Py_INCREF(Py_None);
	return Py_None;
}

static char doc_redisplay[] = "\
redisplay() -> None\n\
Change what's displayed on the screen to reflect the current\n\
contents of the line buffer.\
";

/* Table of functions exported by the module */

static struct PyMethodDef readline_methods[] =
{
	{"parse_and_bind", parse_and_bind, METH_VARARGS, doc_parse_and_bind},
	{"get_line_buffer", get_line_buffer, 
	 METH_NOARGS, doc_get_line_buffer},
	{"insert_text", insert_text, METH_VARARGS, doc_insert_text},
	{"redisplay", (PyCFunction)redisplay, METH_NOARGS, doc_redisplay},
	{"read_init_file", read_init_file, METH_VARARGS, doc_read_init_file},
	{"read_history_file", read_history_file, 
	 METH_VARARGS, doc_read_history_file},
	{"write_history_file", write_history_file, 
	 METH_VARARGS, doc_write_history_file},
	{"get_history_item", get_history_item,
	 METH_VARARGS, doc_get_history_item},
	{"get_current_history_length", get_current_history_length,
	 METH_NOARGS, doc_get_current_history_length},
 	{"set_history_length", set_history_length, 
	 METH_VARARGS, set_history_length_doc},
 	{"get_history_length", get_history_length, 
	 METH_VARARGS, get_history_length_doc},
	{"set_completer", set_completer, METH_VARARGS, doc_set_completer},
	{"get_begidx", get_begidx, METH_NOARGS, doc_get_begidx},
	{"get_endidx", get_endidx, METH_NOARGS, doc_get_endidx},

	{"set_completer_delims", set_completer_delims, 
	 METH_VARARGS, doc_set_completer_delims},
	{"add_history", py_add_history, METH_VARARGS, doc_add_history},
	{"get_completer_delims", get_completer_delims, 
	 METH_NOARGS, doc_get_completer_delims},
	
	{"set_startup_hook", set_startup_hook, METH_VARARGS, doc_set_startup_hook},
#ifdef HAVE_RL_PRE_INPUT_HOOK
	{"set_pre_input_hook", set_pre_input_hook, METH_VARARGS, doc_set_pre_input_hook},
#endif
	{0, 0}
};

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

static int
on_hook(PyObject *func, PyThreadState *tstate)
{
	int result = 0;
	if (func != NULL) {
		PyObject *r;
		PyThreadState *save_tstate;
		/* Note that readline is called with the interpreter
		   lock released! */
		save_tstate = PyThreadState_Swap(NULL);
		PyEval_RestoreThread(tstate);
		r = PyObject_CallFunction(func, NULL);
		if (r == NULL)
			goto error;
		if (r == Py_None) 
			result = 0;
		else 
			result = PyInt_AsLong(r);
		Py_DECREF(r);
		goto done;
	  error:
		PyErr_Clear();
		Py_XDECREF(r);
	  done:
		PyEval_SaveThread();
		PyThreadState_Swap(save_tstate);
	}
	return result;
}

static int
on_startup_hook(void)
{
	return on_hook(startup_hook, startup_hook_tstate);
}

#ifdef HAVE_RL_PRE_INPUT_HOOK
static int
on_pre_input_hook(void)
{
	return on_hook(pre_input_hook, pre_input_hook_tstate);
}
#endif

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

static char *
on_completion(char *text, int state)
{
	char *result = NULL;
	if (completer != NULL) {
		PyObject *r;
		PyThreadState *save_tstate;
		/* Note that readline is called with the interpreter
		   lock released! */
		save_tstate = PyThreadState_Swap(NULL);
		PyEval_RestoreThread(completer_tstate);
		/* Don't use the default filename completion if we
		 * have a custom completion function... */
		rl_attempted_completion_over = 1;
		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();
		PyThreadState_Swap(save_tstate);
	}
	return result;
}


/* a more flexible constructor that saves the "begidx" and "endidx"
 * before calling the normal completer */

char **
flex_complete(char *text, int start, int end)
{
	Py_XDECREF(begidx);
	Py_XDECREF(endidx);
	begidx = PyInt_FromLong((long) start);
	endidx = PyInt_FromLong((long) end);
	return completion_matches(text, *on_completion);
}

/* Helper to initialize GNU readline properly. */

static void
setup_readline(void)
{
	rl_readline_name = "python";
#if defined(PYOS_OS2) && defined(PYCC_GCC)
	/* Allow $if term= in .inputrc to work */
	rl_terminal_name = getenv("TERM");
#endif
	/* Force rebind of TAB to insert-tab */
	rl_bind_key('\t', rl_insert);
	/* Bind both ESC-TAB and ESC-ESC to the completion function */
	rl_bind_key_in_map ('\t', rl_complete, emacs_meta_keymap);
	rl_bind_key_in_map ('\033', rl_complete, emacs_meta_keymap);
	/* Set our hook functions */
	rl_startup_hook = (Function *)on_startup_hook;
#ifdef HAVE_RL_PRE_INPUT_HOOK
	rl_pre_input_hook = (Function *)on_pre_input_hook;
#endif
	/* Set our completion function */
	rl_attempted_completion_function = (CPPFunction *)flex_complete;
	/* Set Python word break characters */
	rl_completer_word_break_characters =
		strdup(" \t\n`~!@#$%^&*()-=+[{]}\\|;:'\",<>/?");
		/* All nonalphanums except '.' */

	begidx = PyInt_FromLong(0L);
	endidx = PyInt_FromLong(0L);
	/* Initialize (allows .inputrc to override)
	 *
	 * XXX: A bug in the readline-2.2 library causes a memory leak
	 * inside this function.  Nothing we can do about it.
	 */
	rl_initialize();
}


/* Interrupt handler */

static jmp_buf jbuf;

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


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

static char *
call_readline(char *prompt)
{
	size_t n;
	char *p, *q;
	PyOS_sighandler_t old_inthandler;
	
	old_inthandler = PyOS_setsig(SIGINT, onintr);
	if (setjmp(jbuf)) {
#ifdef HAVE_SIGRELSE
		/* This seems necessary on SunOS 4.1 (Rasmus Hahn) */
		sigrelse(SIGINT);
#endif
		PyOS_setsig(SIGINT, old_inthandler);
		return NULL;
	}
	rl_event_hook = PyOS_InputHook;
	p = readline(prompt);
	PyOS_setsig(SIGINT, old_inthandler);

	/* We must return a buffer allocated with PyMem_Malloc. */
	if (p == NULL) {
		p = PyMem_Malloc(1);
		if (p != NULL)
			*p = '\0';
		return p;
	}
	n = strlen(p);
	if (n > 0)
		add_history(p);
	/* Copy the malloc'ed buffer into a PyMem_Malloc'ed one and
	   release the original. */
	q = p;
	p = PyMem_Malloc(n+2);
	if (p != NULL) {
		strncpy(p, q, n);
		p[n] = '\n';
		p[n+1] = '\0';
	}
	free(q);
	return p;
}


/* Initialize the module */

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

DL_EXPORT(void)
initreadline(void)
{
	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();
	}
}