cpython/Modules/readline.c

663 lines
16 KiB
C

/* 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", (PyCFunction)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", (PyCFunction)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", (PyCFunction)get_begidx, METH_NOARGS, doc_get_begidx},
{"get_endidx", (PyCFunction)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", (PyCFunction)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();
}
}