Operating System Utilities¶
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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- Py_InteractiveFlagis true, this function also returns true if the filename pointer is NULL or if the name is equal to one of the strings- '<stdin>'or- '???'.
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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. 
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int PyOS_CheckStack()¶
- Return true when the interpreter runs out of stack space. This is a reliable check, but is only available when - USE_STACKCHECKis defined (currently on Windows using the Microsoft Visual C++ compiler).- USE_STACKCHECKwill be defined automatically; you should never change the definition in your own code.
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PyOS_sighandler_t PyOS_getsig(int i)¶
- Return the current signal handler for signal i. This is a thin wrapper around either - sigaction()or- signal(). Do not call those functions directly!- PyOS_sighandler_tis a typedef alias for- void (*)(int).
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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 - sigaction()or- signal(). Do not call those functions directly!- PyOS_sighandler_tis a typedef alias for- void (*)(int).
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wchar_t* Py_DecodeLocale(const char* arg, size_t *size)¶
- Decode a byte string from the locale encoding with the surrogateescape error handler: undecodable bytes are decoded as characters in range U+DC80..U+DCFF. If a byte sequence can be decoded as a surrogate character, escape the bytes using the surrogateescape error handler instead of decoding them. - Return a pointer to a newly allocated wide character string, use - PyMem_RawFree()to free the memory. If size is not- NULL, write the number of wide characters excluding the null character into- *size- Return - NULLon decoding error or memory allocation error. If size is not- NULL,- *sizeis set to- (size_t)-1on memory error or set to- (size_t)-2on decoding error.- Decoding errors should never happen, unless there is a bug in the C library. - Use the - Py_EncodeLocale()function to encode the character string back to a byte string.- See also - The - PyUnicode_DecodeFSDefaultAndSize()and- PyUnicode_DecodeLocaleAndSize()functions.- New in version 3.5. 
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char* Py_EncodeLocale(const wchar_t *text, size_t *error_pos)¶
- Encode a wide character string to the locale encoding with the surrogateescape error handler: surrogate characters in the range U+DC80..U+DCFF are converted to bytes 0x80..0xFF. - Return a pointer to a newly allocated byte string, use - PyMem_Free()to free the memory. Return- NULLon encoding error or memory allocation error- If error_pos is not - NULL,- *error_posis set to the index of the invalid character on encoding error, or set to- (size_t)-1otherwise.- Use the - Py_DecodeLocale()function to decode the bytes string back to a wide character string.- See also - The - PyUnicode_EncodeFSDefault()and- PyUnicode_EncodeLocale()functions.- New in version 3.5. 
System Functions¶
These are utility functions that make functionality from the sys module
accessible to C code.  They all work with the current interpreter thread’s
sys module’s dict, which is contained in the internal thread state structure.
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PyObject *PySys_GetObject(const char *name)¶
- Return value: Borrowed reference.Return the object name from the sysmodule or NULL if it does not exist, without setting an exception.
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int PySys_SetObject(const char *name, PyObject *v)¶
- Set name in the - sysmodule to v unless v is NULL, in which case name is deleted from the sys module. Returns- 0on success,- -1on error.
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void PySys_ResetWarnOptions()¶
- Reset - sys.warnoptionsto an empty list.
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void PySys_AddWarnOption(wchar_t *s)¶
- Append s to - sys.warnoptions.
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void PySys_AddWarnOptionUnicode(PyObject *unicode)¶
- Append unicode to - sys.warnoptions.
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void PySys_SetPath(wchar_t *path)¶
- Set - sys.pathto 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).
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void PySys_WriteStdout(const char *format, ...)¶
- Write the output string described by format to - 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 “%.<N>s” where <N> is a decimal number calculated so that <N> 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 - sys.stdoutis unset, the formatted message is written to the real (C level) stdout.
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void PySys_WriteStderr(const char *format, ...)¶
- As - PySys_WriteStdout(), but write to- sys.stderror stderr instead.
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void PySys_FormatStdout(const char *format, ...)¶
- Function similar to PySys_WriteStdout() but format the message using - PyUnicode_FromFormatV()and don’t truncate the message to an arbitrary length.- New in version 3.2. 
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void PySys_FormatStderr(const char *format, ...)¶
- As - PySys_FormatStdout(), but write to- sys.stderror stderr instead.- New in version 3.2. 
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void PySys_AddXOption(const wchar_t *s)¶
- Parse s as a set of - -Xoptions and add them to the current options mapping as returned by- PySys_GetXOptions().- New in version 3.2. 
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PyObject *PySys_GetXOptions()¶
- Return value: Borrowed reference.Return the current dictionary of -Xoptions, similarly tosys._xoptions. On error, NULL is returned and an exception is set.New in version 3.2. 
Process Control¶
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void Py_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 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 - abort()is called which will attempt to produce a- corefile.
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void Py_Exit(int status)¶
- Exit the current process. This calls - Py_Finalize()and then calls the standard C library function- exit(status).
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int Py_AtExit(void (*func)())¶
- Register a cleanup function to be called by - 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,- 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.
