remove perl dependency for bash

[rickywu]

refer to #1931

juse use builtin histtory and sort by reverse order, and use sed and tr to replace perl

[junegunn]

Please make sure that the existing tests all pass. (make docker-test)
Hmm, I don't think there's a good way to handle multi-line commands with sed as we do now.

[rickywu]

OK, both sed and awk can do this

fc -lr -2147483648 | sed -r -e 's/^([0-9]+\t) +/\1/g;' | sed -z -r -e 's/\n([0-9]+\t)/\x00/g;'

or

fc -lr -2147483648 | awk 'BEGIN{RS="\n[0-9]+\t ";ORS="\x00";OFS=""}NR==1{$0=gensub(/^([0-9]+\t) +/,"\\1","g",$0)}{print num,$0}{num=gensub(/\n([0-9]+\t) +/,"\\1","g",RT)}'
Here are the two options test result:

docker run -it fzf-arch
[exited]
Run options: --seed 37568

Running:

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

Finished in 68.682246s, 2.0384 runs/s, 1.7181 assertions/s.

140 runs, 118 assertions, 0 failures, 0 errors, 0 skips

One problem is sed -z option is only available version 4.2.2+ which released at Sat, 22 Dec 2012

New option -z (--null-data) to separate lines by ASCII NUL characters.

[junegunn]

One problem is sed -z option is only available version 4.2.2+ which released at Sat, 22 Dec 2012

Then we can't use it, macOS Catalina ships with old BSD sed (2005).

$ sed -z
sed: illegal option -- z

[junegunn]

This is unrelated.

[rickywu]

gensub is not available for BSD awk on mac os, just hold on, I'll find a better solution

[junegunn]

Yeah, thanks. Is there a reason you want to remove perl dependency? Perl is available on virtually every Unixy system nowadays.

[rickywu]

I‘ve tested awk with sub function works well on mac OS and passed docker-test, you can review now.

The reason is I want to use fzf in docker container and
most of bash distribution include sed and awk but except perl, such as alpine Linux distribution

[junegunn]

works well on mac OS

While it works with GNU awk, which can be installed using Homebrew (brew install gawk -> /usr/local/bin/awk), it doesn't work with the default awk from macOS (/usr/bin/awk). Can you check again? Thanks.

[rickywu]

Yes, you are right.
I've checked, for compatible BSD bash, the only option is use perl.
So I changed check if gnu awk available, otherwise use perl, is this solution acceptable?

[junegunn]

Thanks, but I'm not a fan of this code branch. (FYI, we rely on Perl even more since 18261fe)

Minimizing dependency is nice, but I'd just use Perl in this case as I don't want to increase code complexity and I don't think it's too much to require Perl on interactive command-line environments.

The reason is I want to use fzf in docker container and
most of bash distribution include sed and awk but except perl, such as alpine Linux distribution

That's a valid point but such Docker images are mainly for building lightweight containers rather than interactive command-line environments. So I think it's forgivable that interactive fzf scripts don't work in those images out of the box without additional installation steps. Perl on Alpine is quite small, so I suggest that you just install Perl when you build your Docker containers.