Use functions for everything

Original message: https://t.me/TelegramDesktopTalk/95813

tg-setup

@@ -1,31 +1,71 @@
 #!/bin/sh
 
-permerr(){
+# Check whether script is executed by root
+f_perm_err(){
 	printf "This script has been executed as the root user.\n"
 	printf "Please run it as a regular user instead.\n"
 	exit 1
 }
 
-[ $(id -u) == "0" ] && permerr
-
-# Environment variables
-user_id=$(id -u)
-user_name=$(whoami)
-tmp="/tmp/tg-setup"
-data="/home/${user_name}/.local/share/TelegramDesktop"
-
-# Establish the tmpfs for Telegram
-mkdir $tmp
-cp -rv $data/* $tmp
-sudo mount -t tmpfs -o size=256M,mode=1777 telegram $data
-cp -rv $tmp/* $data/
-telegram
-
-read -p "Do you want to remove the cached application data? (y/n) " remove_app_data
-
-f_remove_app_data(){
-	sudo umount telegram
-	rm -r $tmp
+f_mount_storage(){
+	printf "Mounting $1 storage...\n"
+	[ ! -d $2 ] && mkdir $2
+	sudo mount -t tmpfs -o size=256M,mode=1777 tg-$1 $2
 }
 
-[ "$remove_app_data" != "n" ] && f_remove_app_data
+f_remove_cache(){
+	printf "Removing unnecessary data from $1 storage...\n"
+	rm -r "$2/tdata/user_data/cache/"* 2>/dev/null
+	rm -r "$2/tdata/user_data/media_cache/"* 2>/dev/null
+	rm -r "$2/tdata/user_data#?/cache/"* 2>/dev/null
+	rm -r "$2/tdata/user_data#?/media_cache/"* 2>/dev/null
+	rm -r "$2/tdata/emoji/cache"* 2>/dev/null
+	rm -r "$2/DebugLogs/"* 2>/dev/null
+}
+
+f_copy_data(){
+	printf "Copying data from $1 to $2 storage...\n"
+	cp -r $3/* $4
+}
+
+f_rsync_data(){
+	printf "Copying data from $1 to $2 storage...\n"
+	rsync -a --delete $3/ $4
+}
+
+f_umount_storage(){
+	printf "Removing $1 storage...\n"
+	sudo umount tg-$1
+	[ ! -z $2 ] && \
+		printf "Deleting directory...\n" && \
+		rm -r $2
+}
+
+[ $(id -u) == "0" ] && f_perm_err
+
+# Environment variables
+tmp="/tmp/tg-temporary"
+data="/home/$USER/.local/share/TelegramDesktop"
+
+# Reduce permissions for written files
+umask 0077
+
+# Establish the tmpfs for Telegram
+f_remove_cache internal $data
+f_mount_storage transitory $tmp
+f_copy_data internal transitory $data $tmp
+f_mount_storage temporary $data
+f_copy_data transitory temporary $tmp $data
+f_umount_storage transitory $tmp
+
+# Launch Telegram application
+printf "Launching Telegram...\n"
+telegram 2>/dev/null
+
+# Tear down the tmpfs for Telegram
+f_remove_cache temporary $data
+f_mount_storage transitory $tmp
+f_copy_data temporary transitory $data $tmp
+f_umount_storage temporary
+f_rsync_data transitory internal $tmp $data
+f_umount_storage transitory $tmp