These features are largely the same as we have in pcb-rnd.

Important: until the first beta release the file format is UNSTABLE, which 
means I can introduce breaking change (without version bumping) in the 
file format any time, so you can't expect a file saved earlier will work 
with a later version. This flux will end with our Beta release (deadline: 
October). So please use load/save for testing, but don't yet attempt to 
use sch-rnd in anything remotely production.


1. save as

Either from the File menu or using {f a}. Will always ask for a file name.
Saves in our native lihata sheet format (no file format documentation 
available yet).


2. save

If the current sheet has a file name (was originally loaded or was new but 
already saved with an user assigned file name), do a silent save (no 
dialog box, no questions). If there's no file name assigned to the sheet, 
typicially first save of a new sheet, do the same as "save as" does.

Hotkey is {f s}

We do not yet have the persistent save pcb-rnd has, so all saves are 
always done in canonical format (indentation, numerical format, etc).


3. load

File menu load, or {f o}. Brings up a file selection dialog, where you can 
select the sheet to load.

At the moment sch-rnd is like pcb-rnd and can edit only one sheet at a 
time. Later on, before the beta, I will change this, and we will handle 
multi-sheet nicely, but that feature is at the end of my list because of 
dependencues.


4. revert

Simply reloads the file from disk, just like in pcb-rnd. I included this 
feature just to match pcb-rnd features.


5. emergency save

Just like in pcb-rnd we have emergency saves: if sch-rnd thinks something 
bad happened and you likely would lose some of your work, it spends its 
last CPU cycles on a best effort emergency save.

The file name is configured in conf node rc/emergency_name, the default is 
SCH.number-number.save. If you set this to empty, no emergency save is 
done.

Easiest way to test: open a sheet file, edit it, the quit without saving 
-> an SCH.*.save will appear in cwd. Another way to test it is sending a 
SIGTERM to the sch-rnd process after load and edit.

Unlike in pcb-rnd, there is no file format config: we always do the 
emergency save in native format.


6. timed backups

Just like in pcb-rnd, independently of the emergency save, we also have 
timed backups, configured using rc/backup_name and rc/backup_interval. If 
backup interval is 0, no timed backup is made. 

This one saves your sheet every interval seconds if it has change. 
Especially useful while we are in alpha or beta state and we expect 
sch-rnd to crash often or just ruin data in various ways.

Interval is set to 60 sec by default.

Unlike in pcb-rnd, there is no file format config: we always do the
backup save in native format.



7. "file changed on disk" infobar


Another feature that may be familiar from pcb-rnd: open a sheet, then in 
another terminal touch or edit the sheet file. sch-rnd checks all open 
sheet file's modification date every few seconds and pops up an infobar if 
the file-on-disk changed. Interval is configured in 
rc/file_changed_interval (you can disable this feature by setting this to 
0).