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Diffstat (limited to 'Doc/library/posix.rst')
| -rw-r--r-- | Doc/library/posix.rst | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/Doc/library/posix.rst b/Doc/library/posix.rst index c33d9e5..07db2b2 100644 --- a/Doc/library/posix.rst +++ b/Doc/library/posix.rst @@ -38,13 +38,13 @@ Large File Support Several operating systems (including AIX, HP-UX, Irix and Solaris) provide support for files that are larger than 2 GB from a C programming model where -:ctype:`int` and :ctype:`long` are 32-bit values. This is typically accomplished +:c:type:`int` and :c:type:`long` are 32-bit values. This is typically accomplished by defining the relevant size and offset types as 64-bit values. Such files are sometimes referred to as :dfn:`large files`. -Large file support is enabled in Python when the size of an :ctype:`off_t` is -larger than a :ctype:`long` and the :ctype:`long long` type is available and is -at least as large as an :ctype:`off_t`. +Large file support is enabled in Python when the size of an :c:type:`off_t` is +larger than a :c:type:`long` and the :c:type:`long long` type is available and is +at least as large as an :c:type:`off_t`. It may be necessary to configure and compile Python with certain compiler flags to enable this mode. For example, it is enabled by default with recent versions of Irix, but with Solaris 2.6 and 2.7 you need to do something like:: @@ -69,17 +69,22 @@ In addition to many functions described in the :mod:`os` module documentation, .. data:: environ A dictionary representing the string environment at the time the interpreter - was started. For example, ``environ['HOME']`` is the pathname of your home - directory, equivalent to ``getenv("HOME")`` in C. + was started. Keys and values are bytes on Unix and str on Windows. For + example, ``environ[b'HOME']`` (``environ['HOME']`` on Windows) is the + pathname of your home directory, equivalent to ``getenv("HOME")`` in C. Modifying this dictionary does not affect the string environment passed on by :func:`execv`, :func:`popen` or :func:`system`; if you need to change the environment, pass ``environ`` to :func:`execve` or add variable assignments and export statements to the command string for :func:`system` or :func:`popen`. + .. versionchanged:: 3.2 + On Unix, keys and values are bytes. + .. note:: - The :mod:`os` module provides an alternate implementation of ``environ`` which - updates the environment on modification. Note also that updating ``os.environ`` - will render this dictionary obsolete. Use of the :mod:`os` module version of - this is recommended over direct access to the :mod:`posix` module. + The :mod:`os` module provides an alternate implementation of ``environ`` + which updates the environment on modification. Note also that updating + :data:`os.environ` will render this dictionary obsolete. Use of the + :mod:`os` module version of this is recommended over direct access to the + :mod:`posix` module. |