1 .. highlightlang:: c 2 3 .. _os: 4 5 Operating System Utilities 6 ========================== 7 8 9 .. c:function:: int Py_FdIsInteractive(FILE *fp, const char *filename) 10 11 Return true (nonzero) if the standard I/O file *fp* with name *filename* is 12 deemed interactive. This is the case for files for which ``isatty(fileno(fp))`` 13 is true. If the global flag :c:data:`Py_InteractiveFlag` is true, this function 14 also returns true if the *filename* pointer is *NULL* or if the name is equal to 15 one of the strings ``'<stdin>'`` or ``'???'``. 16 17 18 .. c:function:: void PyOS_AfterFork() 19 20 Function to update some internal state after a process fork; this should be 21 called in the new process if the Python interpreter will continue to be used. 22 If a new executable is loaded into the new process, this function does not need 23 to be called. 24 25 26 .. c:function:: int PyOS_CheckStack() 27 28 Return true when the interpreter runs out of stack space. This is a reliable 29 check, but is only available when :const:`USE_STACKCHECK` is defined (currently 30 on Windows using the Microsoft Visual C++ compiler). :const:`USE_STACKCHECK` 31 will be defined automatically; you should never change the definition in your 32 own code. 33 34 35 .. c:function:: PyOS_sighandler_t PyOS_getsig(int i) 36 37 Return the current signal handler for signal *i*. This is a thin wrapper around 38 either :c:func:`sigaction` or :c:func:`signal`. Do not call those functions 39 directly! :c:type:`PyOS_sighandler_t` is a typedef alias for :c:type:`void 40 (\*)(int)`. 41 42 43 .. c:function:: PyOS_sighandler_t PyOS_setsig(int i, PyOS_sighandler_t h) 44 45 Set the signal handler for signal *i* to be *h*; return the old signal handler. 46 This is a thin wrapper around either :c:func:`sigaction` or :c:func:`signal`. Do 47 not call those functions directly! :c:type:`PyOS_sighandler_t` is a typedef 48 alias for :c:type:`void (\*)(int)`. 49 50 .. _systemfunctions: 51 52 System Functions 53 ================ 54 55 These are utility functions that make functionality from the :mod:`sys` module 56 accessible to C code. They all work with the current interpreter thread's 57 :mod:`sys` module's dict, which is contained in the internal thread state structure. 58 59 .. c:function:: PyObject *PySys_GetObject(char *name) 60 61 Return the object *name* from the :mod:`sys` module or *NULL* if it does 62 not exist, without setting an exception. 63 64 .. c:function:: FILE *PySys_GetFile(char *name, FILE *def) 65 66 Return the :c:type:`FILE*` associated with the object *name* in the 67 :mod:`sys` module, or *def* if *name* is not in the module or is not associated 68 with a :c:type:`FILE*`. 69 70 .. c:function:: int PySys_SetObject(char *name, PyObject *v) 71 72 Set *name* in the :mod:`sys` module to *v* unless *v* is *NULL*, in which 73 case *name* is deleted from the sys module. Returns ``0`` on success, ``-1`` 74 on error. 75 76 .. c:function:: void PySys_ResetWarnOptions() 77 78 Reset :data:`sys.warnoptions` to an empty list. 79 80 .. c:function:: void PySys_AddWarnOption(char *s) 81 82 Append *s* to :data:`sys.warnoptions`. 83 84 .. c:function:: void PySys_SetPath(char *path) 85 86 Set :data:`sys.path` to a list object of paths found in *path* which should 87 be a list of paths separated with the platform's search path delimiter 88 (``:`` on Unix, ``;`` on Windows). 89 90 .. c:function:: void PySys_WriteStdout(const char *format, ...) 91 92 Write the output string described by *format* to :data:`sys.stdout`. No 93 exceptions are raised, even if truncation occurs (see below). 94 95 *format* should limit the total size of the formatted output string to 96 1000 bytes or less -- after 1000 bytes, the output string is truncated. 97 In particular, this means that no unrestricted "%s" formats should occur; 98 these should be limited using "%.<N>s" where <N> is a decimal number 99 calculated so that <N> plus the maximum size of other formatted text does not 100 exceed 1000 bytes. Also watch out for "%f", which can print hundreds of 101 digits for very large numbers. 102 103 If a problem occurs, or :data:`sys.stdout` is unset, the formatted message 104 is written to the real (C level) *stdout*. 105 106 .. c:function:: void PySys_WriteStderr(const char *format, ...) 107 108 As above, but write to :data:`sys.stderr` or *stderr* instead. 109 110 111 .. _processcontrol: 112 113 Process Control 114 =============== 115 116 117 .. c:function:: void Py_FatalError(const char *message) 118 119 .. index:: single: abort() 120 121 Print a fatal error message and kill the process. No cleanup is performed. 122 This function should only be invoked when a condition is detected that would 123 make it dangerous to continue using the Python interpreter; e.g., when the 124 object administration appears to be corrupted. On Unix, the standard C library 125 function :c:func:`abort` is called which will attempt to produce a :file:`core` 126 file. 127 128 129 .. c:function:: void Py_Exit(int status) 130 131 .. index:: 132 single: Py_Finalize() 133 single: exit() 134 135 Exit the current process. This calls :c:func:`Py_Finalize` and then calls the 136 standard C library function ``exit(status)``. 137 138 139 .. c:function:: int Py_AtExit(void (*func) ()) 140 141 .. index:: 142 single: Py_Finalize() 143 single: cleanup functions 144 145 Register a cleanup function to be called by :c:func:`Py_Finalize`. The cleanup 146 function will be called with no arguments and should return no value. At most 147 32 cleanup functions can be registered. When the registration is successful, 148 :c:func:`Py_AtExit` returns ``0``; on failure, it returns ``-1``. The cleanup 149 function registered last is called first. Each cleanup function will be called 150 at most once. Since Python's internal finalization will have completed before 151 the cleanup function, no Python APIs should be called by *func*. 152
