diff --git a/scripts/_common.sh b/scripts/_common.sh
index 3e8cc87..2106b79 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -6,7 +6,7 @@ readonly time_zone="$(cat /etc/timezone)"
 readonly python_version="$(python3 -V | cut -d' ' -f2 | cut -d. -f1-2)"
 
 # Create special path with / at the end
-if [[ $path == '/' ]]
+if [[ "$path" == '/' ]]
 then
     readonly path2="$path"
 else
@@ -33,20 +33,20 @@ install_pkg_conf() {
 
 install_dependance() {
     # Clean venv is it was on python3 with old version in case major upgrade of debian
-    if [ ! -e $install_dir/venv/bin/python3 ] || [ ! -e $install_dir/venv/lib/python$python_version ]; then
-        ynh_secure_remove --file=$install_dir/venv/bin
-        ynh_secure_remove --file=$install_dir/venv/lib
-        ynh_secure_remove --file=$install_dir/venv/lib64
-        ynh_secure_remove --file=$install_dir/venv/include
-        ynh_secure_remove --file=$install_dir/venv/share
-        ynh_secure_remove --file=$install_dir/venv/pyvenv.cfg
+    if [ ! -e "$install_dir"/venv/bin/python3 ] || [ ! -e "$install_dir/venv/lib/python$python_version" ]; then
+        ynh_secure_remove --file="$install_dir"/venv/bin
+        ynh_secure_remove --file="$install_dir"/venv/lib
+        ynh_secure_remove --file="$install_dir"/venv/lib64
+        ynh_secure_remove --file="$install_dir"/venv/include
+        ynh_secure_remove --file="$install_dir"/venv/share
+        ynh_secure_remove --file="$install_dir"/venv/pyvenv.cfg
     fi
 
     # Create venv if it don't exist
-    test -e $install_dir/venv/bin/python3 || python3 -m venv $install_dir/venv
+    test -e "$install_dir"/venv/bin/python3 || python3 -m venv "$install_dir"/venv
 
     py_dependancy="django==4.2.* future==0.18.* mysqlclient==2.1.* pymysql pillow==10.2.* pylibmc captcha==0.5.* markupsafe==2.0.1 jinja2 sqlalchemy==2.0.18 psd-tools django-pylibmc django_simple_captcha==0.6.* djangosaml2==1.5.* pysaml2==7.2.* pycryptodome==3.16.* cffi==1.15.1 lxml python-ldap==3.4.3"
-    $install_dir/venv/bin/pip3 install --upgrade --timeout=3600 $py_dependancy
+    "$install_dir"/venv/bin/pip3 install --upgrade --timeout=3600 $py_dependancy
 
     # Create symbolic link to venv package on seahub
     ls "$install_dir/venv/lib/python$python_version/site-packages" | while read -r f; do
@@ -69,10 +69,10 @@ set_permission() {
     setfacl -m user:www-data:rX "$install_dir"
     setfacl -m user:www-data:rX "$install_dir/seafile-server-$seafile_version"
     # At install time theses directory are not available
-    test -e $install_dir/seafile-server-$seafile_version/seahub && setfacl -m user:www-data:rX $install_dir/seafile-server-$seafile_version/seahub
-    test -e $install_dir/seafile-server-$seafile_version/seahub/media && setfacl -R -m user:www-data:rX $install_dir/seafile-server-$seafile_version/seahub/media
-    test -e $install_dir/seahub-data && setfacl -m user:www-data:rX $data_dir
-    test -e $install_dir/seahub-data && setfacl -R -m user:www-data:rX $data_dir/seahub-data
+    test -e "$install_dir/seafile-server-$seafile_version/seahub" && setfacl -m user:www-data:rX "$install_dir/seafile-server-$seafile_version/seahub"
+    test -e "$install_dir/seafile-server-$seafile_version/seahub/media" && setfacl -R -m user:www-data:rX "$install_dir/seafile-server-$seafile_version/seahub/media"
+    test -e "$install_dir"/seahub-data && setfacl -m user:www-data:rX "$data_dir"
+    test -e "$install_dir"/seahub-data && setfacl -R -m user:www-data:rX "$data_dir"/seahub-data
 
     find "$data_dir" \(   \! -perm -o= \
                      -o \! -user "$app" \
diff --git a/scripts/change_url b/scripts/change_url
index febbf5e..545ed6d 100644
--- a/scripts/change_url
+++ b/scripts/change_url
@@ -11,14 +11,14 @@ source ./_common.sh
 # Source YunoHost helpers
 source /usr/share/yunohost/helpers
 
-seafile_version=$(ynh_app_upstream_version)
+seafile_version="$(ynh_app_upstream_version)"
 
 # Create special path with / at the end
 if [[ $path == '/' ]]
 then
-    path2=$path
+    path2="$path"
 else
-    path2=$path"/"
+    path2="$path/"
 fi
 
 #=================================================
@@ -46,14 +46,14 @@ pkill -f seahub || true
 ynh_script_progression --message="Updating seafile configuration..."
 
 # Update Seafile Config
-ynh_add_config --template=seahub_settings.py --destination=$install_dir/conf/seahub_settings.py
-ynh_add_config --template=ccnet.conf --destination=$install_dir/conf/ccnet.conf
-ynh_add_config --template=gunicorn.conf.py --destination=$install_dir/conf/gunicorn.conf.py
-ynh_add_config --template=seafdav.conf --destination=$install_dir/conf/seafdav.conf
+ynh_add_config --template=seahub_settings.py --destination="$install_dir"/conf/seahub_settings.py
+ynh_add_config --template=ccnet.conf --destination="$install_dir"/conf/ccnet.conf
+ynh_add_config --template=gunicorn.conf.py --destination="$install_dir"/conf/gunicorn.conf.py
+ynh_add_config --template=seafdav.conf --destination="$install_dir"/conf/seafdav.conf
 
 # Update permissions
-ynh_permission_url --permission=file_server --url=$domain/seafhttp
-ynh_permission_url --permission=webdav --url=$domain/seafdav
+ynh_permission_url --permission=file_server --url="$domain"/seafhttp
+ynh_permission_url --permission=webdav --url="$domain"/seafdav
 
 # Clean url in config in DB
 clean_url_in_db_config
diff --git a/scripts/install b/scripts/install
index 3a23c56..ad3425f 100644
--- a/scripts/install
+++ b/scripts/install
@@ -103,7 +103,7 @@ ln -s "$data_dir"/seahub-data "$install_dir"/seahub-data
 ln -s /var/log/"$app" "$install_dir"/logs
 
 # Fix local warning
-ynh_replace_string --match_string=en_US.UTF-8 --replace_string=${LANG:-'en_US.UTF-8'} --target_file="$install_dir/seafile-server-$seafile_version/seahub.sh"
+ynh_replace_string --match_string=en_US.UTF-8 --replace_string="${LANG:-'en_US.UTF-8'}" --target_file="$install_dir/seafile-server-$seafile_version/seahub.sh"
 
 # Add Seafile Server to startup
 ynh_script_progression --message="Configuring a systemd service..."
diff --git a/scripts/remove b/scripts/remove
index 8da5613..3614395 100644
--- a/scripts/remove
+++ b/scripts/remove
@@ -11,7 +11,7 @@ source ./_common.sh
 # Source YunoHost helpers
 source /usr/share/yunohost/helpers
 
-seafile_version=$(ynh_app_upstream_version)
+seafile_version="$(ynh_app_upstream_version)"
 
 #=================================================
 # STANDARD REMOVE
@@ -34,8 +34,8 @@ if [ "$YNH_APP_PURGE" -eq 1 ]; then
     ynh_secure_remove --file=/var/log/"$app"
 fi
 ynh_script_progression --message="Removing code..."
-ynh_secure_remove --file=/var/www/$app
-ynh_secure_remove --file=/opt/yunohost/$app
+ynh_secure_remove --file=/var/www/"$app"
+ynh_secure_remove --file=/opt/yunohost/"$app"
 
 # Remove databases
 ynh_script_progression --message="Removing databases..."
diff --git a/scripts/restore b/scripts/restore
index 0d03a58..830de29 100644
--- a/scripts/restore
+++ b/scripts/restore
@@ -11,13 +11,10 @@ source ../settings/scripts/_common.sh
 # Source YunoHost helpers
 source /usr/share/yunohost/helpers
 
-seafile_version=$(ynh_app_upstream_version)
+seafile_version="$(ynh_app_upstream_version)"
 
 ynh_script_progression --message="Loading settings..."
 
-# Retrieve arguments
-seafile_version=$(ynh_app_upstream_version)
-
 #=================================================
 # STANDARD RESTORATION STEPS
 #=================================================
diff --git a/scripts/upgrade b/scripts/upgrade
index 0df166d..fd2b9bd 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -11,8 +11,8 @@ source ./_common.sh
 # Source YunoHost helpers
 source /usr/share/yunohost/helpers
 
-seafile_version=$(ynh_app_upstream_version)
-installed_version=${YNH_APP_CURRENT_VERSION/~ynh*/}
+seafile_version="$(ynh_app_upstream_version)"
+installed_version="${YNH_APP_CURRENT_VERSION/~ynh*/}"
 
 ensure_vars_set
 
@@ -47,7 +47,7 @@ fi
 
 # Set missing settings
 if [ -z "${seahub_secret_key:-}" ]; then
-    seahub_secret_key=$(grep -P 'SECRET_KEY\s*=\s*".+"' "$install_dir"/conf/seahub_settings.py | cut -d'"' -f2)
+    seahub_secret_key="$(grep -P 'SECRET_KEY\s*=\s*".+"' "$install_dir"/conf/seahub_settings.py | cut -d'"' -f2)"
     ynh_app_setting_set --app="$app" --key=seahub_secret_key --value="$seahub_secret_key"
 fi
 
@@ -113,7 +113,7 @@ ynh_script_progression --message="Configuring application..."
 set_permission
 
 # do the upgrade    ( the ";&" syntax mean when it go in the first case which is true it do all the next case)
-case $installed_version in
+case "$installed_version" in
 "4."* )
 	# Update seafile by script
 	ynh_die "Upgrade form the version 4.x was removed. Upgrade from this version won't be supported any more."
@@ -168,11 +168,11 @@ sudo -u "$app" bash "$install_dir/seafile-server-$seafile_version/upgrade/minor-
 clean_url_in_db_config
 
 # Update seafile config files
-ynh_add_jinja_config --template=seahub_settings.py --destination=$install_dir/conf/seahub_settings.py
-ynh_add_config --template=seafile.conf --destination=$install_dir/conf/seafile.conf
-ynh_add_config --template=ccnet.conf --destination=$install_dir/conf/ccnet.conf
-ynh_add_config --template=gunicorn.conf.py --destination=$install_dir/conf/gunicorn.conf.py
-ynh_add_config --template=seafdav.conf --destination=$install_dir/conf/seafdav.conf
+ynh_add_jinja_config --template=seahub_settings.py --destination="$install_dir"/conf/seahub_settings.py
+ynh_add_config --template=seafile.conf --destination="$install_dir"/conf/seafile.conf
+ynh_add_config --template=ccnet.conf --destination="$install_dir"/conf/ccnet.conf
+ynh_add_config --template=gunicorn.conf.py --destination="$install_dir"/conf/gunicorn.conf.py
+ynh_add_config --template=seafdav.conf --destination="$install_dir"/conf/seafdav.conf
 ynh_add_config --template=seafevents.conf --destination="$install_dir"/conf/seafevents.conf
 
 # Fix local warning
@@ -223,10 +223,10 @@ sleep 2
 
 # remove old version files
 ynh_script_progression --message="Cleaning system and updating settings..."
-ls "$install_dir" | grep "seafile-server-" | grep -E -v "(${seafile_version//./\\.})|(latest)" | \
-while read -r f
-do
-    ynh_secure_remove --file="$install_dir/$f"
+for f in "$install_dir"/seafile-server-*;do
+    if [[ ! "$f" =~ ${seafile_version//./\\.}|latest ]]; then
+        ynh_secure_remove --file="$f"
+    fi
 done
 
 ynh_script_progression --message="Upgrade of $app completed" --last