From 313c9edfd0aa9399fcb8b0489e79fbc4706a3d38 Mon Sep 17 00:00:00 2001
From: Luka Vandervelden <lukc@upyum.com>
Date: Sun, 17 Nov 2019 19:05:22 +0100
Subject: [PATCH] Improved user and group removal, simpler APIs.

---
 src/passwd.cr | 66 ++++++++++++++++++++++++++++++++-------------------
 1 file changed, 42 insertions(+), 24 deletions(-)

diff --git a/src/passwd.cr b/src/passwd.cr
index 8e5b2e6..1c00c32 100644
--- a/src/passwd.cr
+++ b/src/passwd.cr
@@ -56,9 +56,9 @@ class Passwd
 		false
 	end
 
-	def get_user(uid : Int32) : Passwd::User?
+	def get_user(&block) : Passwd::User?
 		each_user do |user|
-			if user.uid == uid
+			if yield user
 				set_user_groups user
 
 				return user
@@ -66,21 +66,24 @@ class Passwd
 		end
 	end
 
+	def get_user(uid : Int32)
+		get_user &.uid.==(uid)
+	end
+
+	def get_user(login : String)
+		get_user &.login.==(login)
+	end
+
 	##
 	# Will fail if the user is found but the password is invalid.
-	def get_user(login : String, password : String) : Passwd::User?
+	# Use this method if you somehow need to check the password…
+	# Be careful though, your system probably does not use SHA256 hashes as
+	# passwords. You should use this only on your own passwd and group files.
+	def get_user(login : String, password : String)
 		hash = Passwd.hash_password password
 
-		each_user do |user|
-			if user.login == login
-				if user.password_hash == hash
-					set_user_groups user
-
-					return user
-				end
-
-				next
-			end
+		get_user do |user|
+			user.login == login && user.password_hash == hash
 		end
 	end
 
@@ -201,27 +204,26 @@ class Passwd
 		FileUtils.cp tempfile.path, path
 	end
 
-	def remove_user(uid)
-		user = get_user(uid)
-
-		return nil unless user
-
-		user_login = user.login
-
+	def remove_user_from_groups(user)
 		new_group = group_as_array.map do |line|
 			group = Group.new line
 
-			group.users.select! &.!=(user_login)
+			group.users.select! &.!=(user.login)
+			group.users.select! &.!=(user.uid.to_s)
 
 			group.to_csv
 		end
 
 		safe_rewrite @group, new_group.join('\n') + '\n'
+	end
 
+	def remove_user(&block)
 		new_passwd = passwd_as_array.compact_map do |line|
 			user = User.new line
 
-			if uid == user.uid
+			if yield user
+				remove_user_from_groups user
+
 				nil
 			else
 				line.join ':'
@@ -231,11 +233,19 @@ class Passwd
 		safe_rewrite @passwd, new_passwd.join("\n") + "\n"
 	end
 
-	def remove_group(gid)
+	def remove_user(uid : Int32)
+		remove_user &.uid.==(uid)
+	end
+
+	def remove_user(login : String)
+		remove_user &.login.==(login)
+	end
+
+	def remove_group(&block)
 		new_group = group_as_array.compact_map do |line|
 			group = Group.new line
 
-			if gid == group.gid
+			if yield group
 				nil
 			else
 				line.join ':'
@@ -244,5 +254,13 @@ class Passwd
 
 		safe_rewrite @group, new_group.join('\n') + '\n'
 	end
+
+	def remove_group(gid : Int32)
+		remove_group &.gid.==(gid)
+	end
+
+	def remove_group(name : String)
+		remove_group &.name.==(name)
+	end
 end