Operating System Utilities¶

intPy_FdIsInteractive(FILE *fp, const char *filename)¶

Return true (nonzero) if the standard I/O filefp with namefilename isdeemed interactive. This is the case for files for whichisatty(fileno(fp))is true. If the global flagPy_InteractiveFlag is true, this functionalso returns true if thefilename pointer isNULL or if the name is equal toone of the strings'<stdin>' or'???'.

voidPyOS_AfterFork()¶

Function to update some internal state after a process fork; this should becalled 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 needto be called.

intPyOS_CheckStack()¶

Return true when the interpreter runs out of stack space. This is a reliablecheck, but is only available whenUSE_STACKCHECK is defined (currentlyon Windows using the Microsoft Visual C++ compiler).USE_STACKCHECKwill be defined automatically; you should never change the definition in yourown code.

PyOS_sighandler_tPyOS_getsig(int i)¶

Return the current signal handler for signali. This is a thin wrapper aroundeithersigaction() orsignal(). Do not call those functionsdirectly!PyOS_sighandler_t is a typedef alias forvoid(*)(int).

PyOS_sighandler_tPyOS_setsig(int i, PyOS_sighandler_t h)¶

Set the signal handler for signali to beh; return the old signal handler.This is a thin wrapper around eithersigaction() orsignal(). Donot call those functions directly!PyOS_sighandler_t is a typedefalias forvoid(*)(int).

System Functions¶

These are utility functions that make functionality from thesys moduleaccessible to C code. They all work with the current interpreter thread’ssys module’s dict, which is contained in the internal thread state structure.

PyObject *PySys_GetObject(char *name)¶

Return value: Borrowed reference.

Return the objectname from thesys module orNULL if it doesnot exist, without setting an exception.

FILE *PySys_GetFile(char *name, FILE *def)¶

Return theFILE* associated with the objectname in thesys module, ordef ifname is not in the module or is not associatedwith aFILE*.

intPySys_SetObject(char *name,PyObject *v)¶

Setname in thesys module tov unlessv isNULL, in whichcasename is deleted from the sys module. Returns0 on success,-1on error.

voidPySys_ResetWarnOptions()¶

Resetsys.warnoptions to an empty list.

voidPySys_AddWarnOption(char *s)¶

Appends tosys.warnoptions.

voidPySys_SetPath(char *path)¶

Setsys.path to a list object of paths found inpath which shouldbe a list of paths separated with the platform’s search path delimiter(: on Unix,; on Windows).

voidPySys_WriteStdout(const char *format, ...)¶

Write the output string described byformat tosys.stdout. Noexceptions are raised, even if truncation occurs (see below).

format should limit the total size of the formatted output string to1000 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 “%.<N>s” where <N> is a decimal numbercalculated so that <N> plus the maximum size of other formatted text does notexceed 1000 bytes. Also watch out for “%f”, which can print hundreds ofdigits for very large numbers.

If a problem occurs, orsys.stdout is unset, the formatted messageis written to the real (C level)stdout.

voidPySys_WriteStderr(const char *format, ...)¶

As above, but write tosys.stderr orstderr instead.

Process Control¶

voidPy_FatalError(const char *message)¶

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 wouldmake it dangerous to continue using the Python interpreter; e.g., when theobject administration appears to be corrupted. On Unix, the standard C libraryfunctionabort() is called which will attempt to produce acorefile.

voidPy_Exit(int status)¶

Exit the current process. This callsPy_Finalize() and then calls thestandard C library functionexit(status).

intPy_AtExit(void (*func)())¶

Register a cleanup function to be called byPy_Finalize(). The cleanupfunction will be called with no arguments and should return no value. At most32 cleanup functions can be registered. When the registration is successful,Py_AtExit() returns0; on failure, it returns-1. The cleanupfunction registered last is called first. Each cleanup function will be calledat most once. Since Python’s internal finalization will have completed beforethe cleanup function, no Python APIs should be called byfunc.