"""Append module search paths for third-party packages to sys.path.

****************************************************************

* This module is automatically imported during initialization. *

****************************************************************

In earlier versions of Python (up to 1.5a3), scripts or modules that

needed to use site-specific modules would place ``import site''

somewhere near the top of their code.  Because of the automatic

import, this is no longer necessary (but code that does it still

works).

This will append site-specific paths to the module search path.  On

Unix (including Mac OSX), it starts with sys.prefix and

sys.exec_prefix (if different) and appends

lib/python<version>/site-packages as well as lib/site-python.

On other platforms (such as Windows), it tries each of the

prefixes directly, as well as with lib/site-packages appended.  The

resulting directories, if they exist, are appended to sys.path, and

also inspected for path configuration files.

A path configuration file is a file whose name has the form

<package>.pth; its contents are additional directories (one per line)

to be added to sys.path.  Non-existing directories (or

non-directories) are never added to sys.path; no directory is added to

sys.path more than once.  Blank lines and lines beginning with

'#' are skipped. Lines starting with 'import' are executed.

For example, suppose sys.prefix and sys.exec_prefix are set to

/usr/local and there is a directory /usr/local/lib/python2.5/site-packages

with three subdirectories, foo, bar and spam, and two path

configuration files, foo.pth and bar.pth.  Assume foo.pth contains the

following:

  # foo package configuration

  foo

  bar

  bletch

and bar.pth contains:

  # bar package configuration

  bar

Then the following directories are added to sys.path, in this order:

  /usr/local/lib/python2.5/site-packages/bar

  /usr/local/lib/python2.5/site-packages/foo

Note that bletch is omitted because it doesn't exist; bar precedes foo

because bar.pth comes alphabetically before foo.pth; and spam is

omitted because it is not mentioned in either path configuration file.

After these path manipulations, an attempt is made to import a module

named sitecustomize, which can perform arbitrary additional

site-specific customizations.  If this import fails with an

ImportError exception, it is silently ignored.

"""

import sys

import os

import __builtin__

# Prefixes for site-packages; add additional prefixes like /usr/local here

PREFIXES = [sys.prefix, sys.exec_prefix]

# Enable per user site-packages directory

# set it to False to disable the feature or True to force the feature

ENABLE_USER_SITE = None

# for distutils.commands.install

USER_SITE = None

USER_BASE = None

def makepath(*paths):

    dir = os.path.abspath(os.path.join(*paths))

    return dir, os.path.normcase(dir)

def abs__file__():

    """Set all module' __file__ attribute to an absolute path"""

    for m in sys.modules.values():

        if hasattr(m, '__loader__'):

            continue   # don't mess with a PEP 302-supplied __file__

        try:

            m.__file__ = os.path.abspath(m.__file__)

        except AttributeError:

            continue

def removeduppaths():

    """ Remove duplicate entries from sys.path along with making them

    absolute"""

    # This ensures that the initial path provided by the interpreter contains

    # only absolute pathnames, even if we're running from the build directory.

    L = []

    known_paths = set()

    for dir in sys.path:

        # Filter out duplicate paths (on case-insensitive file systems also

        # if they only differ in case); turn relative paths into absolute

        # paths.

        dir, dircase = makepath(dir)

        if not dircase in known_paths:

            L.append(dir)

            known_paths.add(dircase)

    sys.path[:] = L

    return known_paths

# XXX This should not be part of site.py, since it is needed even when

# using the -S option for Python.  See http://www.python.org/sf/586680

def addbuilddir():

    """Append ./build/lib.<platform> in case we're running in the build dir

    (especially for Guido :-)"""

    from distutils.util import get_platform

    s = "build/lib.%s-%.3s" % (get_platform(), sys.version)

    if hasattr(sys, 'gettotalrefcount'):

        s += '-pydebug'

    s = os.path.join(os.path.dirname(sys.path[-1]), s)

    sys.path.append(s)

def _init_pathinfo():

    """Return a set containing all existing directory entries from sys.path"""

    d = set()

    for dir in sys.path:

        try:

            if os.path.isdir(dir):

                dir, dircase = makepath(dir)

                d.add(dircase)

        except TypeError:

            continue

    return d

def addpackage(sitedir, name, known_paths):

    """Process a .pth file within the site-packages directory:

       For each line in the file, either combine it with sitedir to a path

       and add that to known_paths, or execute it if it starts with 'import '.

    """

    if known_paths is None:

        _init_pathinfo()

        reset = 1

    else:

        reset = 0

    fullname = os.path.join(sitedir, name)

    try:

        f = open(fullname, "rU")

    except IOError:

        return

    with f:

        for line in f:

            if line.startswith("#"):

                continue

            if line.startswith(("import ", "import\t")):

                exec line

                continue

            line = line.rstrip()

            dir, dircase = makepath(sitedir, line)

            if not dircase in known_paths and os.path.exists(dir):

                sys.path.append(dir)

                known_paths.add(dircase)

    if reset:

        known_paths = None

    return known_paths

def addsitedir(sitedir, known_paths=None):

    """Add 'sitedir' argument to sys.path if missing and handle .pth files in

    'sitedir'"""

    if known_paths is None:

        known_paths = _init_pathinfo()

        reset = 1

    else:

        reset = 0

    sitedir, sitedircase = makepath(sitedir)

    if not sitedircase in known_paths:

        sys.path.append(sitedir)        # Add path component

    try:

        names = os.listdir(sitedir)

    except os.error:

        return

    dotpth = os.extsep + "pth"

    names = [name for name in names if name.endswith(dotpth)]

    for name in sorted(names):

        addpackage(sitedir, name, known_paths)

    if reset:

        known_paths = None

    return known_paths

def check_enableusersite():

    """Check if user site directory is safe for inclusion

    The function tests for the command line flag (including environment var),

    process uid/gid equal to effective uid/gid.

    None: Disabled for security reasons

    False: Disabled by user (command line option)

    True: Safe and enabled

    """

    if sys.flags.no_user_site:

        return False

    if hasattr(os, "getuid") and hasattr(os, "geteuid"):

        # check process uid == effective uid

        if os.geteuid() != os.getuid():

            return None

    if hasattr(os, "getgid") and hasattr(os, "getegid"):

        # check process gid == effective gid

        if os.getegid() != os.getgid():

            return None

    return True

def addusersitepackages(known_paths):

    """Add a per user site-package to sys.path

    Each user has its own python directory with site-packages in the

    home directory.

    USER_BASE is the root directory for all Python versions

    USER_SITE is the user specific site-packages directory

    USER_SITE/.. can be used for data.

    """

    global USER_BASE, USER_SITE, ENABLE_USER_SITE

    env_base = os.environ.get("PYTHONUSERBASE", None)

    def joinuser(*args):

        return os.path.expanduser(os.path.join(*args))

    #if sys.platform in ('os2emx', 'riscos'):

    #    # Don't know what to put here

    #    USER_BASE = ''

    #    USER_SITE = ''

    if os.name == "nt":

        base = os.environ.get("APPDATA") or "~"

        USER_BASE = env_base if env_base else joinuser(base, "Python")

        USER_SITE = os.path.join(USER_BASE,

                                 "Python" + sys.version[0] + sys.version[2],

                                 "site-packages")

    else:

        USER_BASE = env_base if env_base else joinuser("~", ".local")

        USER_SITE = os.path.join(USER_BASE, "lib",

                                 "python" + sys.version[:3],

                                 "site-packages")

    if ENABLE_USER_SITE and os.path.isdir(USER_SITE):

        addsitedir(USER_SITE, known_paths)

    return known_paths

def addsitepackages(known_paths):

    """Add site-packages (and possibly site-python) to sys.path"""

    sitedirs = []

    seen = []

    for prefix in PREFIXES:

        if not prefix or prefix in seen:

            continue

        seen.append(prefix)

        if sys.platform in ('os2emx', 'riscos'):

            sitedirs.append(os.path.join(prefix, "Lib", "site-packages"))

        elif os.sep == '/':

            sitedirs.append(os.path.join(prefix, "lib",

                                        "python" + sys.version[:3],

                                        "site-packages"))

            sitedirs.append(os.path.join(prefix, "lib", "site-python"))

        else:

            sitedirs.append(prefix)

            sitedirs.append(os.path.join(prefix, "lib", "site-packages"))

        if sys.platform == "darwin":

            # for framework builds *only* we add the standard Apple

            # locations. Currently only per-user, but /Library and

            # /Network/Library could be added too

            if 'Python.framework' in prefix:

                sitedirs.append(

                    os.path.expanduser(

                        os.path.join("~", "Library", "Python",

                                     sys.version[:3], "site-packages")))

    for sitedir in sitedirs:

        if os.path.isdir(sitedir):

            addsitedir(sitedir, known_paths)

    return known_paths

def setBEGINLIBPATH():

    """The OS/2 EMX port has optional extension modules that do double duty

    as DLLs (and must use the .DLL file extension) for other extensions.

    The library search path needs to be amended so these will be found

    during module import.  Use BEGINLIBPATH so that these are at the start

    of the library search path.

    """

    dllpath = os.path.join(sys.prefix, "Lib", "lib-dynload")

    libpath = os.environ['BEGINLIBPATH'].split(';')

    if libpath[-1]:

        libpath.append(dllpath)

    else:

        libpath[-1] = dllpath

    os.environ['BEGINLIBPATH'] = ';'.join(libpath)

def setquit():

    """Define new built-ins 'quit' and 'exit'.

    These are simply strings that display a hint on how to exit.

    """

    if os.sep == ':':

        eof = 'Cmd-Q'

    elif os.sep == '\\':

        eof = 'Ctrl-Z plus Return'

    else:

        eof = 'Ctrl-D (i.e. EOF)'

    class Quitter(object):

        def __init__(self, name):

            self.name = name

        def __repr__(self):

            return 'Use %s() or %s to exit' % (self.name, eof)

        def __call__(self, code=None):

            # Shells like IDLE catch the SystemExit, but listen when their

            # stdin wrapper is closed.

            try:

                sys.stdin.close()

            except:

                pass

            raise SystemExit(code)

    __builtin__.quit = Quitter('quit')

    __builtin__.exit = Quitter('exit')

class _Printer(object):

    """interactive prompt objects for printing the license text, a list of

    contributors and the copyright notice."""

    MAXLINES = 23

    def __init__(self, name, data, files=(), dirs=()):

        self.__name = name

        self.__data = data

        self.__files = files

        self.__dirs = dirs

        self.__lines = None

    def __setup(self):

        if self.__lines:

            return

        data = None

        for dir in self.__dirs:

            for filename in self.__files:

                filename = os.path.join(dir, filename)

                try:

                    fp = file(filename, "rU")

                    data = fp.read()

                    fp.close()

                    break

                except IOError:

                    pass

            if data:

                break

        if not data:

            data = self.__data

        self.__lines = data.split('\n')

        self.__linecnt = len(self.__lines)

    def __repr__(self):

        self.__setup()

        if len(self.__lines) <= self.MAXLINES:

            return "\n".join(self.__lines)

        else:

            return "Type %s() to see the full %s text" % ((self.__name,)*2)

    def __call__(self):

        self.__setup()

        prompt = 'Hit Return for more, or q (and Return) to quit: '

        lineno = 0

        while 1:

            try:

                for i in range(lineno, lineno + self.MAXLINES):

                    print self.__lines[i]

            except IndexError:

                break

            else:

                lineno += self.MAXLINES

                key = None

                while key is None:

                    key = raw_input(prompt)

                    if key not in ('', 'q'):

                        key = None

                if key == 'q':

                    break

def setcopyright():

    """Set 'copyright' and 'credits' in __builtin__"""

    __builtin__.copyright = _Printer("copyright", sys.copyright)

    if sys.platform[:4] == 'java':

        __builtin__.credits = _Printer(

            "credits",

            "Jython is maintained by the Jython developers (www.jython.org).")

    else:

        __builtin__.credits = _Printer("credits", """\

    Thanks to CWI, CNRI, BeOpen.com, Zope Corporation and a cast of thousands

    for supporting Python development.  See www.python.org for more information.""")

    here = os.path.dirname(os.__file__)

    __builtin__.license = _Printer(

        "license", "See http://www.python.org/%.3s/license.html" % sys.version,

        ["LICENSE.txt", "LICENSE"],

        [os.path.join(here, os.pardir), here, os.curdir])

class _Helper(object):

    """Define the built-in 'help'.

    This is a wrapper around pydoc.help (with a twist).

    """

    def __repr__(self):

        return "Type help() for interactive help, " \

               "or help(object) for help about object."

    def __call__(self, *args, **kwds):

        import pydoc

        return pydoc.help(*args, **kwds)

def sethelper():

    __builtin__.help = _Helper()

def aliasmbcs():

    """On Windows, some default encodings are not provided by Python,

    while they are always available as "mbcs" in each locale. Make

    them usable by aliasing to "mbcs" in such a case."""

    if sys.platform == 'win32':

        import locale, codecs

        enc = locale.getdefaultlocale()[1]

        if enc.startswith('cp'):            # "cp***" ?

            try:

                codecs.lookup(enc)

            except LookupError:

                import encodings

                encodings._cache[enc] = encodings._unknown

                encodings.aliases.aliases[enc] = 'mbcs'

def setencoding():

    """Set the string encoding used by the Unicode implementation.  The

    default is 'ascii', but if you're willing to experiment, you can

    change this."""

    encoding = "ascii" # Default value set by _PyUnicode_Init()

    if 0:

        # Enable to support locale aware default string encodings.

        import locale

        loc = locale.getdefaultlocale()

        if loc[1]:

            encoding = loc[1]

    if 0:

        # Enable to switch off string to Unicode coercion and implicit

        # Unicode to string conversion.

        encoding = "undefined"

    if encoding != "ascii":

        # On Non-Unicode builds this will raise an AttributeError...

        sys.setdefaultencoding(encoding) # Needs Python Unicode build !

def execsitecustomize():

    """Run custom site specific code, if available."""

    try:

        import sitecustomize

    except ImportError:

        pass

def execusercustomize():

    """Run custom user specific code, if available."""

    try:

        import usercustomize

    except ImportError:

        pass

def main():

    global ENABLE_USER_SITE

    abs__file__()

    known_paths = removeduppaths()

    if (os.name == "posix" and sys.path and

        os.path.basename(sys.path[-1]) == "Modules"):

        addbuilddir()

    if ENABLE_USER_SITE is None:

        ENABLE_USER_SITE = check_enableusersite()

    known_paths = addusersitepackages(known_paths)

    known_paths = addsitepackages(known_paths)

    if sys.platform == 'os2emx':

        setBEGINLIBPATH()

    setquit()

    setcopyright()

    sethelper()

    aliasmbcs()

    setencoding()

    execsitecustomize()

    if ENABLE_USER_SITE:

        execusercustomize()

    # Remove sys.setdefaultencoding() so that users cannot change the

    # encoding after initialization.  The test for presence is needed when

    # this module is run as a script, because this code is executed twice.

    if hasattr(sys, "setdefaultencoding"):

        del sys.setdefaultencoding

main()

def _script():

    help = """\

    %s [--user-base] [--user-site]

    Without arguments print some useful information

    With arguments print the value of USER_BASE and/or USER_SITE separated

    by '%s'.

    Exit codes with --user-base or --user-site:

      0 - user site directory is enabled

      1 - user site directory is disabled by user

      2 - uses site directory is disabled by super user

          or for security reasons

     >2 - unknown error

    """