Allow for setting of file location by env

[dantuck]

Environment var RLEDGER_FILE added as optional to set location of ledger file

• Ledger file location is set by -l first and then if not set uses env var.

[ebcrowder]

Thanks for this!

From reading the code and testing the branch code a bit locally, it seems like the user would still have to pass in an argument of -l $RLEDGER_FILE in order for this to work. Was that the intent? From reading the original ledger docs (https://www.ledger-cli.org/3.0/doc/ledger3.html#Environment-variables), env vars can be used in lieu of arguments altogether, which would make calling the tool much less verbose if they are set.

I wonder if we can do that here, too? For example, if $RLEDGER_FILE was set, a user could simply do rust_ledger accounts for accounts, and so on.

We would probably have to unwind how I parse args in main.rs, but I could see that being useful.

However, this iteration looks good and I'd be happy to approve. Just wanted to run the above by you to see what you think.

[dantuck]

Actually I have implemented to that you can have the env var set and use it as you described. To test in one line you can do the following:

RLEDGER_FILE=~/rledger.yaml cargo run rust_ledger balances

or in your .profile or .zprofile

export RLEDGER_FILE="$HOME/rledger.yaml"

If by chance you have this env set you can always specify a different file with -l and that will ignore the env var and use what you pass in to the command.

[ebcrowder]

ah, I see that now! I was setting my env variable incorrectly 😬

Awesome - thanks again for the contribution.

[dantuck]

Glad to help. More to come.