| |
| /* Readline interface for tokenizer.c and [raw_]input() in bltinmodule.c. |
| By default, or when stdin is not a tty device, we have a super |
| simple my_readline function using fgets. |
| Optionally, we can use the GNU readline library. |
| my_readline() has a different return value from GNU readline(): |
| - NULL if an interrupt occurred or if an error occurred |
| - a malloc'ed empty string if EOF was read |
| - a malloc'ed string ending in \n normally |
| */ |
| |
| #include "Python.h" |
| #ifdef MS_WINDOWS |
| #define WIN32_LEAN_AND_MEAN |
| #include "windows.h" |
| #endif /* MS_WINDOWS */ |
| |
| #ifdef __VMS |
| extern char* vms__StdioReadline(FILE *sys_stdin, FILE *sys_stdout, char *prompt); |
| #endif |
| |
| |
| PyThreadState* _PyOS_ReadlineTState; |
| |
| #ifdef WITH_THREAD |
| #include "pythread.h" |
| static PyThread_type_lock _PyOS_ReadlineLock = NULL; |
| #endif |
| |
| int (*PyOS_InputHook)(void) = NULL; |
| |
| /* This function restarts a fgets() after an EINTR error occurred |
| except if PyOS_InterruptOccurred() returns true. */ |
| |
| static int |
| my_fgets(char *buf, int len, FILE *fp) |
| { |
| #ifdef MS_WINDOWS |
| HANDLE hInterruptEvent; |
| #endif |
| char *p; |
| int err; |
| while (1) { |
| if (PyOS_InputHook != NULL) |
| (void)(PyOS_InputHook)(); |
| errno = 0; |
| clearerr(fp); |
| if (_PyVerify_fd(fileno(fp))) |
| p = fgets(buf, len, fp); |
| else |
| p = NULL; |
| if (p != NULL) |
| return 0; /* No error */ |
| err = errno; |
| #ifdef MS_WINDOWS |
| /* Ctrl-C anywhere on the line or Ctrl-Z if the only character |
| on a line will set ERROR_OPERATION_ABORTED. Under normal |
| circumstances Ctrl-C will also have caused the SIGINT handler |
| to fire which will have set the event object returned by |
| _PyOS_SigintEvent. This signal fires in another thread and |
| is not guaranteed to have occurred before this point in the |
| code. |
| |
| Therefore: check whether the event is set with a small timeout. |
| If it is, assume this is a Ctrl-C and reset the event. If it |
| isn't set assume that this is a Ctrl-Z on its own and drop |
| through to check for EOF. |
| */ |
| if (GetLastError()==ERROR_OPERATION_ABORTED) { |
| hInterruptEvent = _PyOS_SigintEvent(); |
| switch (WaitForSingleObjectEx(hInterruptEvent, 10, FALSE)) { |
| case WAIT_OBJECT_0: |
| ResetEvent(hInterruptEvent); |
| return 1; /* Interrupt */ |
| case WAIT_FAILED: |
| return -2; /* Error */ |
| } |
| } |
| #endif /* MS_WINDOWS */ |
| if (feof(fp)) { |
| clearerr(fp); |
| return -1; /* EOF */ |
| } |
| #ifdef EINTR |
| if (err == EINTR) { |
| int s; |
| #ifdef WITH_THREAD |
| PyEval_RestoreThread(_PyOS_ReadlineTState); |
| #endif |
| s = PyErr_CheckSignals(); |
| #ifdef WITH_THREAD |
| PyEval_SaveThread(); |
| #endif |
| if (s < 0) |
| return 1; |
| /* try again */ |
| continue; |
| } |
| #endif |
| if (PyOS_InterruptOccurred()) { |
| return 1; /* Interrupt */ |
| } |
| return -2; /* Error */ |
| } |
| /* NOTREACHED */ |
| } |
| |
| |
| /* Readline implementation using fgets() */ |
| |
| char * |
| PyOS_StdioReadline(FILE *sys_stdin, FILE *sys_stdout, char *prompt) |
| { |
| size_t n; |
| char *p, *pr; |
| |
| n = 100; |
| p = (char *)PyMem_RawMalloc(n); |
| if (p == NULL) |
| return NULL; |
| |
| fflush(sys_stdout); |
| if (prompt) |
| fprintf(stderr, "%s", prompt); |
| fflush(stderr); |
| |
| switch (my_fgets(p, (int)n, sys_stdin)) { |
| case 0: /* Normal case */ |
| break; |
| case 1: /* Interrupt */ |
| PyMem_RawFree(p); |
| return NULL; |
| case -1: /* EOF */ |
| case -2: /* Error */ |
| default: /* Shouldn't happen */ |
| *p = '\0'; |
| break; |
| } |
| n = strlen(p); |
| while (n > 0 && p[n-1] != '\n') { |
| size_t incr = n+2; |
| if (incr > INT_MAX) { |
| PyMem_RawFree(p); |
| PyErr_SetString(PyExc_OverflowError, "input line too long"); |
| return NULL; |
| } |
| pr = (char *)PyMem_RawRealloc(p, n + incr); |
| if (pr == NULL) { |
| PyMem_RawFree(p); |
| PyErr_NoMemory(); |
| return NULL; |
| } |
| p = pr; |
| if (my_fgets(p+n, (int)incr, sys_stdin) != 0) |
| break; |
| n += strlen(p+n); |
| } |
| pr = (char *)PyMem_RawRealloc(p, n+1); |
| if (pr == NULL) { |
| PyMem_RawFree(p); |
| PyErr_NoMemory(); |
| return NULL; |
| } |
| return pr; |
| } |
| |
| |
| /* By initializing this function pointer, systems embedding Python can |
| override the readline function. |
| |
| Note: Python expects in return a buffer allocated with PyMem_Malloc. */ |
| |
| char *(*PyOS_ReadlineFunctionPointer)(FILE *, FILE *, char *); |
| |
| |
| /* Interface used by tokenizer.c and bltinmodule.c */ |
| |
| char * |
| PyOS_Readline(FILE *sys_stdin, FILE *sys_stdout, char *prompt) |
| { |
| char *rv, *res; |
| size_t len; |
| |
| if (_PyOS_ReadlineTState == PyThreadState_GET()) { |
| PyErr_SetString(PyExc_RuntimeError, |
| "can't re-enter readline"); |
| return NULL; |
| } |
| |
| |
| if (PyOS_ReadlineFunctionPointer == NULL) { |
| #ifdef __VMS |
| PyOS_ReadlineFunctionPointer = vms__StdioReadline; |
| #else |
| PyOS_ReadlineFunctionPointer = PyOS_StdioReadline; |
| #endif |
| } |
| |
| #ifdef WITH_THREAD |
| if (_PyOS_ReadlineLock == NULL) { |
| _PyOS_ReadlineLock = PyThread_allocate_lock(); |
| } |
| #endif |
| |
| _PyOS_ReadlineTState = PyThreadState_GET(); |
| Py_BEGIN_ALLOW_THREADS |
| #ifdef WITH_THREAD |
| PyThread_acquire_lock(_PyOS_ReadlineLock, 1); |
| #endif |
| |
| /* This is needed to handle the unlikely case that the |
| * interpreter is in interactive mode *and* stdin/out are not |
| * a tty. This can happen, for example if python is run like |
| * this: python -i < test1.py |
| */ |
| if (!isatty (fileno (sys_stdin)) || !isatty (fileno (sys_stdout))) |
| rv = PyOS_StdioReadline (sys_stdin, sys_stdout, prompt); |
| else |
| rv = (*PyOS_ReadlineFunctionPointer)(sys_stdin, sys_stdout, |
| prompt); |
| Py_END_ALLOW_THREADS |
| |
| #ifdef WITH_THREAD |
| PyThread_release_lock(_PyOS_ReadlineLock); |
| #endif |
| |
| _PyOS_ReadlineTState = NULL; |
| |
| if (rv == NULL) |
| return NULL; |
| |
| len = strlen(rv) + 1; |
| res = PyMem_Malloc(len); |
| if (res != NULL) |
| memcpy(res, rv, len); |
| PyMem_RawFree(rv); |
| |
| return res; |
| } |