Add arguments from PAGER/BAT_PAGER

[Foxboron]

I'm a bit unsure of Rust error handling. Probably also missing a test, but lets just ack the code change first maybe.

Solves #352

Signed-off-by: Morten Linderud morten@linderud.pw

[sharkdp]

Thank you very much for your contribution!

In general, the code-change looks good. It would be great if we could add tests, yes. It's a little bit tricky, because we don't want to rely on the existance of less. Also, we probably don't want to handle any interactive CLI programs in our test suite.

One option could be to write a integration test in the style of

#[test]
fn pager() {
    bat()
        .env("BAT_PAGER", "echo pager-output")
        .arg("test.txt")
        .arg("--paging=always")
        .assert()
        .stdout("pager-output\n")
        .success();
}

There are a few things that we have to test (at least manually):

• If PAGER=less or BAT_PAGER=less, we need to make sure that the default arguments (--RAW-CONTROL-CHARS, ..) are still passed to less (see is_less logic in the code).
• The above should also work if we have PAGER=/usr/bin/less, for example.
• If PAGER="less -X" (or any other arguments), we want to check that the default arguments are not passed to less in addition.
• Setting PAGER="" should disable the pager.

Concerning the error-handling, I could add that in when the other things are done, if that's okay for you.

[Foxboron]

Fixed up on the is_less logic and how it append args. Verified that this gives the desired behavior as described above. Also did a quick swap so the code calling the binary depends on pagerflags. Thus we don't pass /usr/bin/less --flag as the executable when dealing with flags.

[sharkdp]

split will fail if there is a parse error, for example:

split("less --option='foo")   # closing quote is missing

I don't think that unwrap_or would help in such a case?

[sharkdp]

Fixed

[sharkdp]

What happens if we pass BAT_PAGER=""? Does this panic?

Previously, setting BAT_PAGER="" would disable the pager. I'd like to keep this behavior.

[sharkdp]

Yes, it does.

[sharkdp]

Fixed.

[sharkdp]

Same here. We should make sure that this does not panic.

[sharkdp]

Fixed.

[Foxboron]

Ah, yes. That's a lot neater then the improvements i sat with locally.

[sharkdp]

Thank you for your work!