list_screens() returns new instances of Screen

[rhatgadkar]

When the user types list_screens(), new instances of already existing Screen instances are returned. This is a problem, because if a user has enabled logs in a screen session, the user will not be able to get the logs from Screen instances returned by list_screens(). Here is an example scenario when the user is trying to disable and delete logs for all current screen sessions:

scr1 = Screen('scr1', True)
[detached]
There is a screen on:
46165.scr1 (Detached)
There is no screen to be detached matching 46165.

list_screens()
[<Screen 'scr1'>]
scr1.enable_logs('scr1.log')
screen_list = list_screens()
screen_list
[<Screen 'scr1'>]
for i in range(0, len(screen_list)):
... screen_list[i].disable_logs(True)
...
Traceback (most recent call last):
File "", line 2, in
File "screenutils/screen.py", line 104, in disable_logs
system('rm ' + self._logfilename)
TypeError: cannot concatenate 'str' and 'NoneType' objects

In the example above, the user created a Screen with name 'scr1' and a log file with name 'scr1.log'. But when using the Screen instance returned from list_screens(), the user is unable to delete the log file, because list_screens() creates new instances of an already existing Screen. This shouldn't be allowed. list_screens() should return references to already existing instances of Screen.

[kingllama]

Yes. list_screens() right now returns a NEW instance for each existing screen. This might not be the best way of handling this, and the documentation certainly doesn't reflect that fact.

I'm not 100% sure if the function should return new instances or existing one. Perhaps it would be better to deprecate the function in favour of a create_for_all, a get_or_create_for_all and a get_all. I personally can't imagine a situation where you'd want >1 instance for existing screen, but thats not to say it wouldn't come up.

The current workaround for the issue you brought up (deleting the logfiles) would be to .disable_logs(False) and then delete the files some other way.

[Christophe31]

hum, I didn't know there was real users of this script ^^, I don't use it since… many years and don't even use screen anymore (tmux switch)… I'm not so motivated to maintain this project but understand your issue…
kingllama, you want to fork?