Clarify when/how default args are added to less

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Ethan P. 2024-02-07 21:18:12 -08:00
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@ -602,7 +602,8 @@ set, `less` is used by default. If you want to use a different pager, you can ei
`PAGER` variable or set the `BAT_PAGER` environment variable to override what is specified in
`PAGER`.
**Note**: If `PAGER` is `more` or `most`, `bat` will silently use `less` instead to ensure support for colors.
>[!NOTE]
> If `PAGER` is `more` or `most`, `bat` will silently use `less` instead to ensure support for colors.
If you want to pass command-line arguments to the pager, you can also set them via the
`PAGER`/`BAT_PAGER` variables:
@ -613,20 +614,37 @@ export BAT_PAGER="less -RF"
Instead of using environment variables, you can also use `bat`s [configuration file](https://github.com/sharkdp/bat#configuration-file) to configure the pager (`--pager` option).
**Note**: By default, if the pager is set to `less` (and no command-line options are specified),
`bat` will pass the following command line options to the pager: `-R`/`--RAW-CONTROL-CHARS`,
`-F`/`--quit-if-one-screen` and `-X`/`--no-init`. The last option (`-X`) is only used for `less`
versions older than 530.
The `-R` option is needed to interpret ANSI colors correctly. The second option (`-F`) instructs
less to exit immediately if the output size is smaller than the vertical size of the terminal.
This is convenient for small files because you do not have to press `q` to quit the pager. The
third option (`-X`) is needed to fix a bug with the `--quit-if-one-screen` feature in old versions
of `less`. Unfortunately, it also breaks mouse-wheel support in `less`.
### Using `less` as a pager
If you want to enable mouse-wheel scrolling on older versions of `less`, you can pass just `-R` (as
in the example above, this will disable the quit-if-one-screen feature). For less 530 or newer,
it should work out of the box.
When using `less` as a pager, `bat` will automatically pass extra options along to `less`
to improve the experience. Specifically, `-R`/`--RAW-CONTROL-CHARS`, `-F`/`--quit-if-one-screen`,
and under certain conditions, `-X`/`--no-init` and/or `-S`/`--chop-long-lines`.
>[!IMPORTANT]
> These options will not be added if:
> - The pager is not named `less`.
> - The `--pager` argument contains any command-line arguments (e.g. `--pager="less -R"`).
> - The `BAT_PAGER` environment variable contains any command-line arguments (e.g. `export BAT_PAGER="less -R"`)
>
> The `--quit-if-one-screen` option will not be added when:
> - The `--paging=always` argument is used.
> - The `BAT_PAGING` environment is set to `always`.
The `-R` option is needed to interpret ANSI colors correctly.
The `-F` option instructs `less` to exit immediately if the output size is smaller than
the vertical size of the terminal. This is convenient for small files because you do not
have to press `q` to quit the pager.
The `-X` option is needed to fix a bug with the `--quit-if-one-screen` feature in versions
of `less` older than version 530. Unfortunately, it also breaks mouse-wheel support in `less`.
If you want to enable mouse-wheel scrolling on older versions of `less` and do not mind losing
the quit-if-one-screen feature, you can set the pager (via `--pager` or `BAT_PAGER`) to `less -R`.
For `less` 530 or newer, it should work out of the box.
The `-S` option is added when `bat`'s `-S`/`--chop-long-lines` option is used. This tells `less`
to truncate any lines larger than the terminal width.
### Indentation