Add ruby support

[tim-coutinho]

This addresses #38.

[alichtman]

The reinstallation fails on my system.

$ gem list | tail -n+1 | sed 's/(/--version /' | sed 's/)//' | xargs -L 1 gem install
ERROR:  While executing gem ... (Gem::Requirement::BadRequirementError)
    Illformed requirement ["default:"]
ERROR:  While executing gem ... (Gem::Requirement::BadRequirementError)
    Illformed requirement ["default:"]
ERROR:  While executing gem ... (Gem::Requirement::BadRequirementError)
    Illformed requirement ["default:"]
Fetching bundler-unload-1.0.2.gem
Successfully installed bundler-unload-1.0.2
Parsing documentation for bundler-unload-1.0.2
Installing ri documentation for bundler-unload-1.0.2
Done installing documentation for bundler-unload after 0 seconds
1 gem installed
ERROR:  While executing gem ... (Gem::Requirement::BadRequirementError)
    Illformed requirement ["default:"]
ERROR:  While executing gem ... (Gem::Requirement::BadRequirementError)
    Illformed requirement ["default:"]
ERROR:  While executing gem ... (Gem::Requirement::BadRequirementError)
    Illformed requirement ["default:"]
ERROR:  While executing gem ... (Gem::Requirement::BadRequirementError)
    Illformed requirement ["default:"]
ERROR:  While executing gem ... (Gem::Requirement::BadRequirementError)
    Illformed requirement ["default:"]
ERROR:  While executing gem ... (Gem::Requirement::BadRequirementError)
    Illformed requirement ["default:"]

$  gem list | tail -n+1 | sed 's/(/--version /' | sed 's/)//' | xargs -L 1 echo
benchmark --version default: 0.1.0
bigdecimal --version default: 2.0.0
bundler --version default: 2.1.2
bundler-unload --version 1.0.2
cgi --version default: 0.1.0
csv --version default: 3.1.2
date --version default: 3.0.0
delegate --version default: 0.1.0
did_you_mean --version default: 1.4.0
etc --version default: 1.1.0
executable-hooks --version 1.6.0
fcntl --version default: 1.0.0
fiddle --version default: 1.0.0
fileutils --version default: 1.4.1
forwardable --version default: 1.3.1
gdbm --version default: 2.1.0
gem-wrappers --version 1.4.0
getoptlong --version default: 0.1.0
io-console --version default: 0.5.3
ipaddr --version default: 1.2.2
irb --version default: 1.2.1
json --version default: 2.3.0
logger --version default: 1.4.2
matrix --version default: 0.2.0
minitest --version 5.13.0
mutex_m --version default: 0.1.0
net-pop --version default: 0.1.0
net-smtp --version default: 0.1.0
net-telnet --version 0.2.0
observer --version default: 0.1.0
open3 --version default: 0.1.0
openssl --version default: 2.1.2
ostruct --version default: 0.2.0
power_assert --version 1.1.5
prime --version default: 0.1.1
pstore --version default: 0.1.0
psych --version default: 3.1.0
racc --version default: 1.4.16
rake --version 13.0.1
rdoc --version default: 6.2.1
readline --version default: 0.0.2
readline-ext --version default: 0.1.0
reline --version default: 0.1.2
rexml --version default: 3.2.3
rss --version default: 0.2.8
rubygems-bundler --version 1.4.5
rvm --version 1.11.3.9
sdbm --version default: 1.0.0
singleton --version default: 0.1.0
stringio --version default: 0.1.0
strscan --version default: 1.0.3
test-unit --version 3.3.4
timeout --version default: 0.1.0
tracer --version default: 0.1.0
uri --version default: 0.10.0
webrick --version default: 1.6.0
xmlrpc --version 0.3.0
yaml --version default: 0.1.0
zlib --version default: 1.1.0

I think there's probably a better format to keep the install list in that would make it easy to reinstall from. Additionally, please send tested PRs, and definitely make a note if it is untested / there are bugs.

[tim-coutinho]

Interesting, it was working earlier when I was testing it on my machine, perhaps there was a recent change in gem list's functionality that added the default: to some version numbers.

[alichtman]

Suggested change

	print_yellow("Package manager not present.")
	print_path_red("An error occurred while running: $", command)

[alichtman]

I think it makes sense to keep the error messages in run_cmd_write_stdout pretty abstract. It's a util function, and we let the calling function know of the error with the error code returned. A more specific error message can be printed from there.

[tim-coutinho]

True, though there won't be an error code to check in this case, as a FileNotFoundError results in a return of None. I can change it to something like Command not found, which is a bit more general and accurate to what a return of None represents.

[alichtman]

Hmm, interesting. I'm using gem 3.1.2. We might need to run a different command to backup / reinstall with gem. I'm not super familiar with gem, though, and don't have time to dig into it at the moment.

[tim-coutinho]

My latest commit fixes the issue, just had to update the backup command.

[alichtman]

@tim-coutinho Sorry for taking so long to get around to this. Rebase off master and then I'll merge this.