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Miscellaneous OS interfaces
===========================

Miscellaneous OS interfaces.

This module provides a more portable way of using operating system (OS)
dependent functionality than importing an OS dependent built-in module
like `posix' or `nt'.

This module searches for an OS dependent built-in module like `mac' or
`posix' and exports the same functions and data as found there.  The
design of all Python's built-in OS dependent modules is such that as
long as the same functionality is available, it uses the same
interface; e.g., the function `os.stat(PATH)' returns stat information
about PATH in the same format (which happens to have originated with the
POSIX interface).

Extensions peculiar to a particular OS are also available through the
`os' module, but using them is of course a threat to portability!

Note that after the first time `os' is imported, there is _no_
performance penalty in using functions from `os' instead of directly
from the OS dependent built-in module, so there should be _no_ reason
not to use `os'!

The `os' module contains many functions and data values.  The items
below and in the following sub-sections are all available directly from
the `os' module.

`error'
     This exception is raised when a function returns a system-related
     error (e.g., not for illegal argument types).  This is also known
     as the built-in exception `OSError'.  The accompanying value is a
     pair containing the numeric error code from `errno' and the
     corresponding string, as would be printed by the C function
     `perror()'.  See the module `errno' , which contains names for the
     error codes defined by the underlying operating system.

     When exceptions are classes, this exception carries two attributes,
     `errno' and `strerror'.  The first holds the value of the C
     `errno' variable, and the latter holds the corresponding error
     message from `strerror()'.  For exceptions that involve a file
     system path (e.g. `chdir()' or `unlink()'), the exception instance
     will contain a third attribute, `filename', which is the file name
     passed to the function.

     When exceptions are strings, the string for the exception is
     `'OSError''.

`name'
     The name of the OS dependent module imported.  The following names
     have currently been registered: `'posix'', `'nt'', `'dos'',
     `'mac'', `'os2'', `'ce'', `'java''.

`path'
     The corresponding OS dependent standard module for pathname
     operations, e.g., `posixpath' or `macpath'.  Thus, given the
     proper imports, `os.path.split(FILE)' is equivalent to but more
     portable than `posixpath.split(FILE)'.  Note that this is also a
     valid module: it may be imported directly as `os.path'.

Process Parameters

File Object Creation

File Descriptor Operations

Files and Directories

Process Management

Miscellaneous System Information