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5.1 Operating System Utilities

int `Py_FdIsInteractive`(FILE *fp, 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_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 `'<stdin>'` or `'???'`.

long `PyOS_GetLastModificationTime`(char *filename)
  Return the time of last modification of the file filename. The result is encoded in the same way as the timestamp returned by the standard C library function `time()`.

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.

int `PyOS_CheckStack`()
  Return true when the interpreter runs out of stack space. This is a reliable check, but is only available when `USE_STACKCHECK` is defined (currently on Windows using the Microsoft Visual C++ compiler and on the Macintosh). `USE_CHECKSTACK` will be defined automatically; you should never change the definition in your own code.

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_t` is a typedef alias for `void (*)(int)`.

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_t` is a typedef alias for `void (*)(int)`.