replace perl with bash in the bash history widget

[step-]

While awk is POSIX, perl isn't pre-installed on all *nix flavors. This commit replaces perl with a bash script to eliminate dependency on perl.

This commit passed the current test suite with zero errors :

• make error => all test sections 'ok'
• make docker-test => Finished in 52.150847s, 4.1227 runs/s, 36.0684 assertions/s. 215 runs, 1881 assertions, 0 failures, 0 errors, 0 skips

See also: #3295 (same idea replacing awk for perl).

I manually tested this commit on macOS Catalina with bash 3.2, and Linux with bash 3.2 and 4.4. While testing on Linux I reported issue #3309.

Note: This commit needs bash support for associative arrays, available since bash 4, to filter out duplicate history items. On macOS, where 3.2 is the default bash version, fzf will not de-duplicate items unless a newer bash version is installed.

[step-]

I have just played the failing ruby test manually but can't get an error. The test script sends

echo 1st<enter>
echo 2nd<enter>
echo 3d<enter>
echo 3rd<enter>
echo 3rd<enter>
echo 3rd<enter>
echo 4th<enter>
<c-r>
e3d
<c-r>
<enter>
<enter>

and expects fzf to match exactly two lines with " echo 3d" selected.

Then, after the second <c-r> with " echo 3rd" selected.

Then, after the next <enter> with "echo 3rd" in the input buffer. Finally, after the last <enter> with "3rd" in the output buffer.

What's failing? Perhaps it's a white space issue? I noticed that the test expects a single space character before the selected line. My code lines 69 and 77 delete a space that builtin fc introduces. Maybe that?

What baffles me is that I have also run make docker-test again here and it doesn't report an error:

Run options: --seed 64802

# Running:

.......................................................................................................................................................................................................................

Finished in 52.049617s, 4.1307 runs/s, 36.1578 assertions/s.

215 runs, 1882 assertions, 0 failures, 0 errors, 0 skips

[step-]

The integration test action is still failing on the same ruby test. I noticed another difference in the test setup: the action runs ruby tests with LC_ALL=C, unlike the DockerFile.

[junegunn]

Thanks for working on this. But I don't think this is going to make it. I liked your previous awk version because the required code change was minimal, but that is clearly not true here; I don't want to maintain these extra code lines just for a fairly small number of users.

The real deal breaker is the performance. I have 170K+ entries in my command history, and with the original Perl version, the processing is instantaneous, but with this version, it takes longer than a minute to fully process the list, which is unacceptable.

[step-]

Thanks for working on this. But I don't think this is going to make it.
The real deal breaker is the performance.

I would do the same in your place.

I liked your previous awk version because the required code change was minimal.

I liked it too better than this version but the deal breaker with macOS awk is that I know no way to ascertain the last character read in streaming mode. If I had that in my pocket the awk script could work in macOS too with minimal changes. I will keep thinking of a way to do it with awk, which is a favorite tool of mine.

I have 170K+ entries in my command history.

Wow. Good to know to raise to the challenge!

[step-]

@glensc, TLDR; #3313 (comment)