.. highlightlang:: c .. _os: Operating System Utilities ========================== .. c:function:: int Py_FdIsInteractive(FILE *fp, const char *filename) Return true (nonzero) if the standard I/O file *fp* with name *filename* is deemed interactive. This is the case for files for which ``isatty(fileno(fp))`` is true. If the global flag :c:data:`Py_InteractiveFlag` is true, this function also returns true if the *filename* pointer is *NULL* or if the name is equal to one of the strings ``''`` or ``'???'``. .. c:function:: void PyOS_AfterFork() Function to update some internal state after a process fork; this should be called in the new process if the Python interpreter will continue to be used. If a new executable is loaded into the new process, this function does not need to be called. .. c:function:: int PyOS_CheckStack() Return true when the interpreter runs out of stack space. This is a reliable check, but is only available when :const:`USE_STACKCHECK` is defined (currently on Windows using the Microsoft Visual C++ compiler). :const:`USE_STACKCHECK` will be defined automatically; you should never change the definition in your own code. .. c:function:: PyOS_sighandler_t PyOS_getsig(int i) Return the current signal handler for signal *i*. This is a thin wrapper around either :c:func:`sigaction` or :c:func:`signal`. Do not call those functions directly! :c:type:`PyOS_sighandler_t` is a typedef alias for :c:type:`void (\*)(int)`. .. c:function:: PyOS_sighandler_t PyOS_setsig(int i, PyOS_sighandler_t h) Set the signal handler for signal *i* to be *h*; return the old signal handler. This is a thin wrapper around either :c:func:`sigaction` or :c:func:`signal`. Do not call those functions directly! :c:type:`PyOS_sighandler_t` is a typedef alias for :c:type:`void (\*)(int)`. .. _systemfunctions: System Functions ================ These are utility functions that make functionality from the :mod:`sys` module accessible to C code. They all work with the current interpreter thread's :mod:`sys` module's dict, which is contained in the internal thread state structure. .. c:function:: PyObject *PySys_GetObject(char *name) Return the object *name* from the :mod:`sys` module or *NULL* if it does not exist, without setting an exception. .. c:function:: FILE *PySys_GetFile(char *name, FILE *def) Return the :c:type:`FILE*` associated with the object *name* in the :mod:`sys` module, or *def* if *name* is not in the module or is not associated with a :c:type:`FILE*`. .. c:function:: int PySys_SetObject(char *name, PyObject *v) Set *name* in the :mod:`sys` module to *v* unless *v* is *NULL*, in which case *name* is deleted from the sys module. Returns ``0`` on success, ``-1`` on error. .. c:function:: void PySys_ResetWarnOptions() Reset :data:`sys.warnoptions` to an empty list. .. c:function:: void PySys_AddWarnOption(wchar_t *s) Append *s* to :data:`sys.warnoptions`. .. c:function:: void PySys_AddWarnOptionUnicode(PyObject *unicode) Append *unicode* to :data:`sys.warnoptions`. .. c:function:: void PySys_SetPath(wchar_t *path) Set :data:`sys.path` to a list object of paths found in *path* which should be a list of paths separated with the platform's search path delimiter (``:`` on Unix, ``;`` on Windows). .. c:function:: void PySys_WriteStdout(const char *format, ...) Write the output string described by *format* to :data:`sys.stdout`. No exceptions are raised, even if truncation occurs (see below). *format* should limit the total size of the formatted output string to 1000 bytes or less -- after 1000 bytes, the output string is truncated. In particular, this means that no unrestricted "%s" formats should occur; these should be limited using "%.s" where is a decimal number calculated so that plus the maximum size of other formatted text does not exceed 1000 bytes. Also watch out for "%f", which can print hundreds of digits for very large numbers. If a problem occurs, or :data:`sys.stdout` is unset, the formatted message is written to the real (C level) *stdout*. .. c:function:: void PySys_WriteStderr(const char *format, ...) As :c:func:`PySys_WriteStdout`, but write to :data:`sys.stderr` or *stderr* instead. .. c:function:: void PySys_FormatStdout(const char *format, ...) Function similar to PySys_WriteStdout() but format the message using :c:func:`PyUnicode_FromFormatV` and don't truncate the message to an arbitrary length. .. versionadded:: 3.2 .. c:function:: void PySys_FormatStderr(const char *format, ...) As :c:func:`PySys_FormatStdout`, but write to :data:`sys.stderr` or *stderr* instead. .. versionadded:: 3.2 .. c:function:: void PySys_AddXOption(const wchar_t *s) Parse *s* as a set of :option:`-X` options and add them to the current options mapping as returned by :c:func:`PySys_GetXOptions`. .. versionadded:: 3.2 .. c:function:: PyObject *PySys_GetXOptions() Return the current dictionary of :option:`-X` options, similarly to :data:`sys._xoptions`. On error, *NULL* is returned and an exception is set. .. versionadded:: 3.2 .. _processcontrol: Process Control =============== .. c:function:: void Py_FatalError(const char *message) .. index:: single: abort() Print a fatal error message and kill the process. No cleanup is performed. This function should only be invoked when a condition is detected that would make it dangerous to continue using the Python interpreter; e.g., when the object administration appears to be corrupted. On Unix, the standard C library function :c:func:`abort` is called which will attempt to produce a :file:`core` file. .. c:function:: void Py_Exit(int status) .. index:: single: Py_Finalize() single: exit() Exit the current process. This calls :c:func:`Py_Finalize` and then calls the standard C library function ``exit(status)``. .. c:function:: int Py_AtExit(void (*func) ()) .. index:: single: Py_Finalize() single: cleanup functions Register a cleanup function to be called by :c:func:`Py_Finalize`. The cleanup function will be called with no arguments and should return no value. At most 32 cleanup functions can be registered. When the registration is successful, :c:func:`Py_AtExit` returns ``0``; on failure, it returns ``-1``. The cleanup function registered last is called first. Each cleanup function will be called at most once. Since Python's internal finalization will have completed before the cleanup function, no Python APIs should be called by *func*.