Printing to stdout

[Bob Wilson]

Hi folks,

   I recently upgraded to Ledger 3.3.2-20230330, from 3.2.1-20200518.

Previously, running a command like `ledger -f ledger.dat balance ^Assets` would print results directly to the screen and return me to the prompt, but now that same command prints results to some kind of temporary screen that disappears when I hit `q`. It's like the difference between `cat` and `less`. Sorry I don't know the right terminology!

As a workaround, I can pipe the command into cat, and then it prints to the screen. Is there a way to just print to the screen by default?

Thanks!

Bob Wilson

[John Wiegley]

>>>>> "BW" == Bob Wilson <mills...@gmail.com> writes:

BW> Previously, running a command like `ledger -f ledger.dat balance ^ Assets`
BW> would print results directly to the screen and return me to the prompt,
BW> but now that same command prints results to some kind of temporary screen
BW> that disappears when I hit `q`. It's like the difference between `cat` and
BW> `less`. Sorry I don't know the right terminology!

Can you try with the --no-pager option? I’m not sure why the default behavior
would have changed, though…

John

[Bob Wilson]

--no-pager works. Terminology in hand, the guide suggested looking at the LEDGER_PAGER environment variable, which is unset on my platform.

I installed via homebrew (I'm on macos 13.4). Perhaps some detail on how they compiled ledger is relevant?

[John Wiegley]

>>>>> "BW" == Bob Wilson <mills...@gmail.com> writes:

BW> --no-pager works. Terminology in hand, the guide suggested looking at the
BW> LEDGER_PAGER environment variable, which is unset on my platform.

BW> I installed via homebrew (I'm on macos 13.4). Perhaps some detail on how
BW> they compiled ledger is relevant?

It looks like this may have broken in commit
21280a9da3ca6ed70a10f95e1ef0717d5f65ee99:

commit 21280a9da3ca6ed70a10f95e1ef0717d5f65ee99
Author: Martin Michlmayr <t...@cyrius.com>
Date: Tue Jun 16 13:17:53 2020 +0800

Use PAGER when environment variable is set

The code looked for "less" if $PAGER is not set, but it didn't
actually use $PAGER when it it defined.

Fixes #1674

Nothing else since that earlier release date has changed the PAGER logic.

John

[Alexis]

Thanks John for providing support and thanks for raising this issue Bob.
Looking at the code there are few questions that arise for me:

* Should ledger really be looking for and use less if PAGER is unset?
Isn't the absence of PAGER and indicator that the user prefers their
output straight to the terminal?

* When looking for less shouldn't ledger search all directories in PATH
instead of hard-coded locations?
If yes, does anyone know of a UNIX PATH searching function readily
available, e.g. in the Boost Filesystem Library¹ before a custom
one is added?

* Where and how is LEDGER_PAGER used in the source code?
A quick grep for LEDGER_PAGER did not

Is there some generic code that allows any ledger command-line option
to be used as an upper-cased and LEDGER_-prefix environment variable?
If yes, where is it implemented?

* How could this be tested along with other unit tests, so that
once a desired behaviour is defined its implementation is tested.


Alexis

¹ https://www.boost.org/doc/libs/1_82_0/libs/filesystem/doc/index.htm

[John Wiegley]

>>>>> Alexis <surr...@gmail.com> writes:

> * Should ledger really be looking for and use less if PAGER is unset? Isn't
> the absence of PAGER and indicator that the user prefers their output
> straight to the terminal?

I don’t think it should. If PAGER is not set, it shouldn’t use a pager…

> * When looking for less shouldn't ledger search all directories in PATH
> instead of hard-coded locations? If yes, does anyone know of a UNIX PATH
> searching function readily available, e.g. in the Boost Filesystem Library¹
> before a custom one is added?

Yes, searching PATH is The Right Way.

> * Where and how is LEDGER_PAGER used in the source code?
> A quick grep for LEDGER_PAGER did not

> Is there some generic code that allows any ledger command-line option
> to be used as an upper-cased and LEDGER_-prefix environment variable?
> If yes, where is it implemented?

Yes, the code to do so begins here:

https://github.com/ledger/ledger/blob/master/src/global.cc#L394

> * How could this be tested along with other unit tests, so that once a
> desired behaviour is defined its implementation is tested.

You could use a pager that ignores everything and just outputs “I was used”,
and then set the test expectation to that value?

John