record historical command runtimes for later prediction.

track historical runtimes for this directory and command, predict if there's time for a sandwich on this run

sandwatch

Remember how long commands take, tell me if I have enough time to make a sandwich?

This is inspired by arbtt, the shell built-in time, and the rust utility tally.

The name was suggested by qu1j0t3.

Why?

Rather than telling me how long something has taken, I would like to know roughly how long this task will take, based on historical records.

Sandwatch records the current directory, the command line, and the runtime for a command.

When running a new command that matches the directory and the first two words of the command line, sandwatch reports expected completion time in sandwich units (five minutes?).

How to use it?

It's a wrapper command. sandwatch cabal build or sandwatch make or whatever you like. Perhaps one day this will become a shell builtin written in Rust.

How to install it?

I suggest using ghcup to install the Haskell compiler and then cabal build in your clone of this git repo.

How does it work?

Sandwatch creates a json file holding entries recording the working directory, the command line, and the execution time.

When a command matches in the same directory, execution from previous runs is average together to give you a rough idea as to whether you have time to make a sandwich or not!

Tell me the root problem?

I don't have insight into the progress of a running program. I wish all programs would dump some number of percent complete events. I could use that to estimate completion time from start time.

Ideas

• Is there a good way to turn command line arguments into a set? For example, ls -o -a is the same as ls -a -o but the strings are different. How could they be the same?
• Is there some good way to automatically figure out how much of a command line to compare for equality?
• How could I compare command lines for equality across directories? While make does different things in different directories, apt install is always the same. How do you decide?