def test_fsdecode_and_fsencode_are_idempotent(self):
a = b'foo\xb1bar'
b = u'foo\udcb1bar'
assert a == fsencode(fsdecode(a))
assert a == fsencode(fsdecode(b))
assert b == fsdecode(fsencode(a))
assert b == fsdecode(fsencode(b))
def update_path_var(existing_path_var, new_path, pathsep=PATH_ENV_SEP):
"""
Return an updated value for the `existing_path_var` PATH-like environment
variable value by adding `new_path` to the front of that variable if
`new_path` is not already part of this PATH-like variable.
"""
if not new_path:
return existing_path_var
existing_path_var = existing_path_var or EMPTY_STRING
# ensure we use unicode or bytes depending on OSes
# TODO: deal also with Python versions
if on_linux and py2:
# bytes ...
existing_path_var = fsencode(existing_path_var)
new_path = fsencode(new_path)
pathsep = fsencode(pathsep)
else:
# ... and unicode otherwise
existing_path_var = fsdecode(existing_path_var)
new_path = fsdecode(new_path)
pathsep = fsdecode(pathsep)
path_elements = existing_path_var.split(pathsep)
if not path_elements:
updated_path_var = new_path
elif new_path not in path_elements:
# add new path to the front of the PATH env var
path_elements.insert(0, new_path)
updated_path_var = pathsep.join(path_elements)
else:
# new path is already in PATH, change nothing
updated_path_var = existing_path_var
if py2:
# always use bytes for env vars...
if isinstance(updated_path_var, compat.unicode):
updated_path_var = fsencode(updated_path_var)
else:
# ... else use unicode
if not isinstance(updated_path_var, compat.unicode):
updated_path_var = fsdecode(updated_path_var)
# at this stage new_path_env is unicode on all OSes on Py3
# and on Py2 it is bytes on Linux and unicode elsewhere
return updated_path_var
def update_path_environment(new_path, _os_module=_os_module):
"""
Update the PATH environment variable by adding `new_path` to the front
of PATH if `new_path` is not alreday in the PATH.
"""
# note: _os_module is used to facilitate mock testing using an
# object with a sep string attribute and an environ mapping
# attribute
if not new_path:
return
new_path = new_path.strip()
if not new_path:
return
path_env = _os_module.environ.get(b'PATH')
if not path_env:
# this is quite unlikely to ever happen, but here for safety
path_env = ''
# ensure we use unicode or bytes depending on OSes
if on_linux:
new_path = fsencode(new_path)
path_env = fsencode(path_env)
sep = _os_module.pathsep
else:
new_path = fsdecode(new_path)
path_env = fsdecode(path_env)
sep = unicode(_os_module.pathsep)
path_segments = path_env.split(sep)
# add lib path to the front of the PATH env var
# this will use bytes on Linux and unicode elsewhere
if new_path not in path_segments:
if not path_env:
new_path_env = new_path
else:
new_path_env = sep.join([new_path, path_env])
if not on_linux:
# recode to bytes using FS encoding
new_path_env = fsencode(new_path_env)
# ... and set the variable back as bytes
_os_module.environ[b'PATH'] = new_path_env
def get_relative_path(path, len_base_path, base_is_dir):
"""
Return a posix relative path from the posix 'path' relative to a
base path of `len_base_path` length where the base is a directory if
`base_is_dir` True or a file otherwise.
"""
path = fileutils.fsdecode(path)
if base_is_dir:
rel_path = path[len_base_path:]
else:
rel_path = fileutils.file_name(path)
return rel_path.lstrip('/')
def load_shared_library(dll_path, lib_dir):
"""
Return the loaded shared library object from the dll_path and adding
`lib_dir` to the path.
"""
if not path.exists(dll_path):
raise ImportError('Shared library does not exists: %(dll_path)r' %
locals())
if lib_dir and not path.exists(lib_dir):
raise ImportError(
'Shared library "lib_dir" does not exists: %(lib_dir)r' % locals())
if on_linux and py2:
# bytes only there ...
if not isinstance(dll_path, bytes):
dll_path = fsencode(dll_path)
else:
# ... unicode everywhere else
if not isinstance(dll_path, compat.unicode):
dll_path = fsdecode(dll_path)
try:
with pushd(lib_dir):
lib = ctypes.CDLL(dll_path)
except OSError as e:
from pprint import pformat
import traceback
msgs = tuple([
'ctypes.CDLL(dll_path): {}'.format(dll_path),
'lib_dir: {}'.format(lib_dir),
'os.environ:\n{}'.format(pformat(dict(os.environ))),
traceback.format_exc(),
])
e.args = tuple(e.args + msgs)
raise e
if lib and lib._name:
return lib
raise ImportError(
'Failed to load shared library with ctypes: %(dll_path)r and lib_dir: '
'%(lib_dir)r' % locals())
