* Add support for BusyBox less as pager
* Run tests/syntax-tests/update.sh to update tests
* Address reviewer's concerns with pull request
* Revert all changes in `test` directory
* Minimize overall diff size
* Detect busybox from separate helper function
* Pass equivalent options to BusyBox from same code by changing from long to
short options
* Remove redundant `if` statement from previous commit
Add test for invalid utf-8
Add `parse_less_version_busybox` to test for invalid program
Add commenting around short options
We can't use #[from] on Error::Msg(String) because String does not implement Error.
(Which it shouldn't; see e.g. https://internals.rust-lang.org/t/impl-error-for-string/8881.)
So we implement From manually for Error::Msg, since our current code was written
in that way for error-chain.
This fixes a bug on Windows where `Command::new` would also run
executables from the current working directory, possibly resulting in
accidental runs of programs called `less`.
As mentioned on #1334 `bat` should not be used as a value for `pager`,
this change checks both the balue of `bat` provided as a parameter or
as an environment variable.
Prevent less from wrapping lines by setting the proper flag when `--wrap=never`.
If the user set a custom value for `--pager`, no additional flag is set.
## [why]
For 'windows' platforms, directly spawning a process (eg, called PATHNAME) bypasses the
usual windows shell machinery for determining which process to execute. Specifically,
the extensions in PATHEXT will not be used to determine the final executable. So,
`PATHNAME.bat`, `PATHNAME.cmd`, ... will *not* be executed even if on they exist on the
PATH; and this is counter to the usual expectation of a Windows user. Additionally,
built-in commands, such as `echo` and `dir`, will never be accessible as they do not
have a PATH to execute and, so, will never be found.
To use the usual machinery, giving access to PATHNAME.bat and `echo`, execute the PATHNAME
using the windows shell, eg `cmd /d/c PATHNAME`. Note this may expose the constructed
command line to the windows shell quoting vagaries (sadly, that may be part of the price).
Following Windows standards, the ComSpec environment variable is used to determine which
shell to use, with a fallback to the "modern", built-in `cmd` shell.
We used to call `less` with
``` bash
less --RAW-CONTROL-CHARS --quit-if-one-screen --no-init
```
We only passed `--no-init` because there was a bug with previous versions
of `less` which required the use of `--no-init` in combination with
`--quit-if-one-screen` to prevent this "no output" issue from happening.
Since bat 0.13, [we omit the `--no-init` option](0ecc94956b/src/output.rs (L85-L97))
if we can detect that the version of `less` is higher than or equal to 530. We
did that because `--no-init` breaks mouse support and because [less 530 fixed
the above-mentioned bug](http://www.greenwoodsoftware.com/less/news.530.html).
However, it seems that this bug was *not* fixed on Windows!
According to @gwsw, the issue should be fixed with less 559 on Windows.
closes#887
When using `less` version 551 or newer, `bat` will now pass the `--mouse` argument, allowing
for (better) mouse scrolling support in some terminals.
closes#904
