def expandvars(path: AnyStr) -> AnyStr:
"""Expand shell variables of form $var and ${var}. Unknown variables
are left unchanged."""
global _varprog, _varprogb
if isinstance(path, bytes):
if b'$' not in path:
return path
if not _varprogb:
import re
_varprogb = re.compile(br'\$(\w+|\{[^}]*\})', re.ASCII)
search = _varprogb.search
start = b'{'
end = b'}'
else:
if '$' not in path:
return path
if not _varprog:
import re
_varprog = re.compile(r'\$(\w+|\{[^}]*\})', re.ASCII)
search = _varprog.search
start = '{'
end = '}'
i = 0
while True:
m = search(path, i)
if not m:
break
i, j = m.span(0)
name = Undefined(Union[str, bytes])
name = m.group(1)
if name.startswith(start) and name.endswith(end):
name = name[1:-1]
if isinstance(name, bytes):
name = str(name, 'ASCII')
if name in os.environ:
tail = path[j:]
value = Undefined(Union[str, bytes])
value = os.environ[name]
if isinstance(path, bytes):
value = value.encode('ASCII')
path = path[:i] + value
i = len(path)
path += tail
else:
i = j
return path
def expandvars(path: AnyStr) -> AnyStr:
"""Expand shell variables of form $var and ${var}. Unknown variables
are left unchanged."""
global _varprog, _varprogb
if isinstance(path, bytes):
if b'$' not in path:
return path
if not _varprogb:
import re
_varprogb = re.compile(br'\$(\w+|\{[^}]*\})', re.ASCII)
search = _varprogb.search
start = b'{'
end = b'}'
else:
if '$' not in path:
return path
if not _varprog:
import re
_varprog = re.compile(r'\$(\w+|\{[^}]*\})', re.ASCII)
search = _varprog.search
start = '{'
end = '}'
i = 0
while True:
m = search(path, i)
if not m:
break
i, j = m.span(0)
name = Undefined(Union[str, bytes])
name = m.group(1)
if name.startswith(start) and name.endswith(end):
name = name[1:-1]
if isinstance(name, bytes):
name = str(name, 'ASCII')
if name in os.environ:
tail = path[j:]
value = Undefined(Union[str, bytes])
value = os.environ[name]
if isinstance(path, bytes):
value = value.encode('ASCII')
path = path[:i] + value
i = len(path)
path += tail
else:
i = j
return path
