2 /* Readline interface for tokenizer.c and [raw_]input() in bltinmodule.c.
3 By default, or when stdin is not a tty device, we have a super
4 simple my_readline function using fgets.
5 Optionally, we can use the GNU readline library.
6 my_readline() has a different return value from GNU readline():
7 - NULL if an interrupt occurred or if an error occurred
8 - a malloc'ed empty string if EOF was read
9 - a malloc'ed string ending in \n normally
14 #define WIN32_LEAN_AND_MEAN
16 #endif /* MS_WINDOWS */
19 extern char* vms__StdioReadline(FILE *sys_stdin
, FILE *sys_stdout
, char *prompt
);
23 PyThreadState
* _PyOS_ReadlineTState
;
27 static PyThread_type_lock _PyOS_ReadlineLock
= NULL
;
30 int (*PyOS_InputHook
)(void) = NULL
;
33 int Py_RISCOSWimpFlag
;
36 /* This function restarts a fgets() after an EINTR error occurred
37 except if PyOS_InterruptOccurred() returns true. */
40 my_fgets(char *buf
, int len
, FILE *fp
)
44 if (PyOS_InputHook
!= NULL
)
45 (void)(PyOS_InputHook
)();
47 p
= fgets(buf
, len
, fp
);
49 return 0; /* No error */
51 /* In the case of a Ctrl+C or some other external event
52 interrupting the operation:
53 Win2k/NT: ERROR_OPERATION_ABORTED is the most recent Win32
54 error code (and feof() returns TRUE).
55 Win9x: Ctrl+C seems to have no effect on fgets() returning
56 early - the signal handler is called, but the fgets()
57 only returns "normally" (ie, when Enter hit or feof())
59 if (GetLastError()==ERROR_OPERATION_ABORTED
) {
60 /* Signals come asynchronously, so we sleep a brief
61 moment before checking if the handler has been
62 triggered (we cant just return 1 before the
63 signal handler has been called, as the later
64 signal may be treated as a separate interrupt).
67 if (PyOS_InterruptOccurred()) {
68 return 1; /* Interrupt */
70 /* Either the sleep wasn't long enough (need a
71 short loop retrying?) or not interrupted at all
72 (in which case we should revisit the whole thing!)
73 Logging some warning would be nice. assert is not
74 viable as under the debugger, the various dialogs
75 mean the condition is not true.
78 #endif /* MS_WINDOWS */
86 PyEval_RestoreThread(_PyOS_ReadlineTState
);
88 s
= PyErr_CheckSignals();
97 if (PyOS_InterruptOccurred()) {
98 return 1; /* Interrupt */
100 return -2; /* Error */
106 /* Readline implementation using fgets() */
109 PyOS_StdioReadline(FILE *sys_stdin
, FILE *sys_stdout
, char *prompt
)
114 if ((p
= PyMem_MALLOC(n
)) == NULL
)
119 fprintf(stderr
, "%s", prompt
);
122 if(Py_RISCOSWimpFlag
)
123 fprintf(stderr
, "\x0cr%s\x0c", prompt
);
125 fprintf(stderr
, "%s", prompt
);
129 switch (my_fgets(p
, (int)n
, sys_stdin
)) {
130 case 0: /* Normal case */
132 case 1: /* Interrupt */
137 default: /* Shouldn't happen */
142 while (n
> 0 && p
[n
-1] != '\n') {
144 p
= PyMem_REALLOC(p
, n
+ incr
);
147 if (incr
> INT_MAX
) {
148 PyErr_SetString(PyExc_OverflowError
, "input line too long");
150 if (my_fgets(p
+n
, (int)incr
, sys_stdin
) != 0)
154 return PyMem_REALLOC(p
, n
+1);
158 /* By initializing this function pointer, systems embedding Python can
159 override the readline function.
161 Note: Python expects in return a buffer allocated with PyMem_Malloc. */
163 char *(*PyOS_ReadlineFunctionPointer
)(FILE *, FILE *, char *);
166 /* Interface used by tokenizer.c and bltinmodule.c */
169 PyOS_Readline(FILE *sys_stdin
, FILE *sys_stdout
, char *prompt
)
173 if (_PyOS_ReadlineTState
== PyThreadState_GET()) {
174 PyErr_SetString(PyExc_RuntimeError
,
175 "can't re-enter readline");
180 if (PyOS_ReadlineFunctionPointer
== NULL
) {
182 PyOS_ReadlineFunctionPointer
= vms__StdioReadline
;
184 PyOS_ReadlineFunctionPointer
= PyOS_StdioReadline
;
189 if (_PyOS_ReadlineLock
== NULL
) {
190 _PyOS_ReadlineLock
= PyThread_allocate_lock();
194 _PyOS_ReadlineTState
= PyThreadState_GET();
195 Py_BEGIN_ALLOW_THREADS
197 PyThread_acquire_lock(_PyOS_ReadlineLock
, 1);
200 /* This is needed to handle the unlikely case that the
201 * interpreter is in interactive mode *and* stdin/out are not
202 * a tty. This can happen, for example if python is run like
203 * this: python -i < test1.py
205 if (!isatty (fileno (sys_stdin
)) || !isatty (fileno (sys_stdout
)))
206 rv
= PyOS_StdioReadline (sys_stdin
, sys_stdout
, prompt
);
208 rv
= (*PyOS_ReadlineFunctionPointer
)(sys_stdin
, sys_stdout
,
213 PyThread_release_lock(_PyOS_ReadlineLock
);
216 _PyOS_ReadlineTState
= NULL
;