History features

[gavinfernandes2012]

List of history features you (@GarryMorrison) want me to keep/add:

• save history sdb shell command
• Save on exit
• -- start here -- mark in the history file
• Save dates in the history file
• Shell start date
• history sdb shell command
• i sdb shell command

Since our new, GNU Readline implementation (#26) does make most of these features obsolete, tell me which ones you want me to keep. Don't forget that you can press ctrl + r for a reverse search of any command in your loaded history.

[GarryMorrison]

Pretty much want to keep all of them :)
Not sure what you meant by "shell start date"

comments:

1. if you have a long session, and are about to start something that may need to be killed before finishing, it is useful to run 'save history' first
2. as long as config file says save, then yeah, save history on exit
3. currently think it is useful to have start here mark
4. dates are important.
5. ...
6. it is nice to see all recent history all at once
7. again, you get to see all history and then pick and choose

[gavinfernandes2012]

By shell start dates, I meant putting a date in the -- start here -- mark corresponding to the day the shell was started. Don't know how useful it would be because I don't think shell sessions will run for many days at a time, but it is wholly possible.

[GarryMorrison]

It's probably fine without it.

[gavinfernandes2012]

Comments:

1. With prompt_toolkit, the history is saved every time enter is pressed, is that fine?
2. Sure.
3. prompt_toolkit has dates and times, hopefully that should cover this base?
4. "
5. Yeah I leave this be, no need for it any more
6. You could use tail .sdb-history
7. You could use nano .sdb-history, emacs .sdb-history or vi .sdb-history?
   Ctrl + _, Ctrl + v To jump to the bottom in nano
   Esc + > For emacs
   G for vi or something along those lines

I'd rather reduce bloat here and not reimplement code that's implemented elsewhere, it'll be a headache for us and any collaborators in the future.

[GarryMorrison]

1. I guess.
2. ok
3. yup.
4. yup
5. yup
6. nope. I still like seeing the history in the shell
7. nope. I like my i command, I use it a lot.

[gavinfernandes2012]

@GarryMorrison If we intend to move ahead with prompt_toolkit, we won't be able to specify separate options for loading and saving in the config file, we either load and save, or don't do either. We can overwrite the history before starting the input loop as an alternative to saving without loading, but that's just about it really.
Let me know on how you want me to proceed.

[GarryMorrison]

OK. I guess we need to change:

save-shell-history = False
load-shell-history = True

to:

use-shell-history = False

The problem with this is that if we set this to true, and the shell history location is '.' then we dump a copy everywhere we run the shell. That's not ideal. Hence I guess set it to default of False.

[gavinfernandes2012]

Or we can change . to ~/.sdb or something similar.

We could also do what flake8 and yapf do. Hell even git does it in a way.
Suppose we have a project in a directory called someproj.

If the project needs to follow a different flake8 or yapf config from the rest of the system, we put a .flake8 or .yapf config file in it (or something along those lines). And yapf and flake first refer to the config in ~, and then in .yapf in the current directory, so any changes in the current directories dot file, override the ones in ~.

We could specify a .sdb_config file (I'm open to name suggestions), that performs a similar purpose, and that could have a use-shell-history and shell-history-location parameter as well, so when you're in your someproj directory, you have a local history enabled, but when you're in another directory, you use the settings in ~/.sdb/config.

Do tell me if you think this would suit our project or not.

[GarryMorrison]

I guess yeah, maybe set shell-history-location to default to ~/.sdb.
I prefer . but it is a matter of choosing the best values for default, and I can change as needed.

Yeah, I guess we could go with the ~ then .sdb_config idea.

[gavinfernandes2012]

@GarryMorrison History length isn't configurable either Source (Using prompt_toolkit), unless we try adding it to the History base class and working from there. If we really want to we could try adding it and then create a pull request to the prompt_toolkit github repo.