Add ruby support

shallow_backup/backup.py

@@ -138,13 +138,19 @@ def run_cmd_if_no_dry_run(command, dest, dry_run) -> int:
 	if not dry_run:
 		overwrite_dir_prompt_if_needed(backup_path, skip)
 
-	for mgr in ["brew", "brew cask", "gem"]:
+	for mgr in ["brew", "brew cask"]:
 		# deal with package managers that have spaces in them.
 		print_pkg_mgr_backup(mgr)
 		command = f"{mgr} list"
 		dest = f"{backup_path}/{mgr.replace(' ', '-')}_list.txt"
 		run_cmd_if_no_dry_run(command, dest, dry_run)
 
+	# ruby
+	print_pkg_mgr_backup("gem")
+	command = "gem list | tail -n+1 | sed 's/(/--version /' | sed 's/)//'"
+	dest = f"{backup_path}/gem_list.txt"
+	run_cmd_if_no_dry_run(command, dest, dry_run)
+
 	# cargo
 	print_pkg_mgr_backup("cargo")
 	command = "ls {}".format(home_prefix(".cargo/bin/"))

shallow_backup/reinstall.py

@@ -165,7 +165,9 @@ def run_cmd_if_no_dry_run(command, dry_run) -> int:
 		elif pm == "macports":
 			print_red_bold("WARNING: Macports reinstallation is not supported.")
 		elif pm == "gem":
-			print_red_bold("WARNING: Gem reinstallation is not supported.")
+			print_pkg_mgr_reinstall(pm)
+			cmd = f"cat {packages_path}/gem_list.txt | xargs -L 1 sudo gem install --no-ri --no-rdoc"
+			run_cmd_if_no_dry_run(cmd, dry_run)
 		elif pm == "cargo":
 			print_red_bold("WARNING: Cargo reinstallation is not possible at the moment.\
 						   \n -> https://github.com/rust-lang/cargo/issues/5593")