def open_file_or_device(number, name, mode='I', access='R', lock='', reclen=128, defext=''):
""" Open a file or device specified by name. """
if (not name) or (number < 0) or (number > max_files):
# bad file number; also for name='', for some reason
raise error.RunError(52)
if number in state.io_state.files:
# file already open
raise error.RunError(55)
name, mode = str(name), mode.upper()
inst = None
split_colon = name.upper().split(':')
if len(split_colon) > 1: # : found
dev_name = split_colon[0] + ':'
dev_param = split_colon[1]
try:
inst = device_open(dev_name, number, mode, access, lock, reclen, dev_param)
except KeyError:
if len(dev_name) > 2:
# devname could be A:, B:, C:, etc.. but anything longer is an error (bad file number, for some reason).
raise error.RunError(52)
if not inst:
# translate the file name to something DOS-ish if necessary
if mode in ('O', 'A'):
# don't open output or append files more than once
check_file_not_open(name)
if mode in ('I', 'L'):
name = oslayer.native_path(name, defext)
else:
# random files: try to open matching file
# if it doesn't exist, create an all-caps 8.3 file name
name = oslayer.native_path(name, defext, make_new=True)
# obtain a lock
request_lock(name, lock, access)
# open the file
fhandle = oslayer.open_file(name, mode, access)
# apply the BASIC file wrapper
if mode in ('S', 'L'): # save, load
inst = BaseFile(fhandle, name, number, mode, access, lock)
elif mode in ('I', 'O', 'A'):
inst = TextFile(fhandle, name, number, mode, access, lock)
else:
inst = RandomFile(fhandle, name, number, mode, access, lock, reclen)
return inst
def check_file_not_open(path):
""" Raise an error if the file is open. """
for f in state.io_state.files:
if oslayer.native_path(path) == state.io_state.files[f].name:
raise error.RunError(55)
