From 17c14c004e821291effa243ae1690d974a768cea Mon Sep 17 00:00:00 2001
From: Rafi59 <rafi59_dev@srvmaison.fr.nf>
Date: Mon, 3 Jul 2017 09:26:31 +0200
Subject: [PATCH] [enh] Add helper

---
 scripts/_common.sh | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/scripts/_common.sh b/scripts/_common.sh
index 02dd131..e82e1cc 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -191,6 +191,41 @@ ynh_remove_logrotate () {
 		sudo rm "/etc/logrotate.d/$app"
 	fi
 }
+# Verify the checksum and backup the file if it's different
+# This helper is primarily meant to allow to easily backup personalised/manually 
+# modified config files.
+#
+# $app should be defined when calling this helper
+#
+# usage: ynh_backup_if_checksum_is_different file [compress]
+# | arg: file - The file on which the checksum test will be perfomed.
+# | arg: compress - 1 to compress the backup instead of a simple copy
+# A compression is needed for a file which will be analyzed even if its name is different.
+#
+# | ret: Return the name a the backup file, or nothing
+ynh_backup_if_checksum_is_different () {
+	local file=$1
+	local compress_backup=${2:-0}	# If $2 is empty, compress_backup will set at 0
+	local checksum_setting_name=checksum_${file//[\/ ]/_}	# Replace all '/' and ' ' by '_'
+	local checksum_value=$(ynh_app_setting_get $app $checksum_setting_name)
+	if [ -n "$checksum_value" ]
+	then	# Proceed only if a value was stored into the app settings
+		if ! echo "$checksum_value $file" | sudo md5sum -c --status
+		then	# If the checksum is now different
+			backup_file="$file.backup.$(date '+%d.%m.%y_%Hh%M,%Ss')"
+			if [ $compress_backup -eq 1 ]
+			then
+				sudo tar --create --gzip --file "$backup_file.tar.gz" "$file"	# Backup the current file and compress
+				backup_file="$backup_file.tar.gz"
+			else
+				sudo cp -a "$file" "$backup_file"	# Backup the current file
+			fi
+			echo "File $file has been manually modified since the installation or last upgrade. So it has been duplicated in $backup_file" >&2
+			echo "$backup_file"	# Return the name of the backup file
+		fi
+	fi
+}
+
 
 # Create a dedicated php-fpm config
 final_path=$DESTDIR