diff --git a/README.md b/README.md
index 7d7bc88..aa204e4 100644
--- a/README.md
+++ b/README.md
@@ -57,7 +57,7 @@ This function check if binary file is avaible in the `PATH`.
 required_commands "ls mv git"
 ```
 
-#### conf_process_dirs
+#### link_dirs
 
 Process a directory that contains others directories an symblink them to the
 destination folder :
@@ -68,10 +68,11 @@ destination folder :
  - **return** : no value, exit the funtion if there is an error on path
 
 ```
-conf_process_dirs "${repository}/config" "${HOME}/.config"
+link_dirs "${repository}/config" "${HOME}/.config"
 ```
+Old function `conf_process_dirs` still avaiable for compatibility.
 
-#### conf_process_files
+#### link_files
 
 Process a directory than contains files and symblink them to the destination
 folder :
@@ -82,9 +83,11 @@ folder :
  - **return** : no value, exit the funtion if there is an error on path
 
 ```
-conf_process_dirs "${repository}/zshrc" "${HOME}"
+link_files "${repository}/zshrc" "${HOME}"
 ```
 
+Old function `conf_process_files` still avaiable for compatibility
+
 #### bin_install
 
 Symblink an executable file to the `~/.local/bin` folder.
diff --git a/src/dotinstall b/src/dotinstall
index 138e91c..07d2a8d 100755
--- a/src/dotinstall
+++ b/src/dotinstall
@@ -32,35 +32,51 @@ die ()
     # $1 : error message before quit
     # $2 : exit code - default 99
     # $3 : 1 if print usage 
+    local message
+    local code
+    local usage
 
-    [ -z $2 ] && $2=99
-    printf "\e[31mFATAL : %s\e[0m\n" "$1"
-    [ $3 == 1 ] && usage
-    exit $2
+    message="$1"
+    code="$2"
+    usage="$3"
+
+    [ -z "$code" ] && code=99
+    printf "\e[31mFATAL : %s\e[0m\n" "$message"
+    [ $usage -eq 1 ] && usage
+    exit $code
 }
 
 error ()
 {
     # print error message in red
     # $@ : message
-
-    printf "\e[31m%s\e[0m\n" "$*"
+    
+    local message
+    message="$*"
+    printf "\e[31m%s\e[0m\n" "$message"
 }
 
 private:get_bootstrap_path ()
 {
     # this function return the absolute path of the bootstrap file
     # $* : path of bootstrap file
+    
+    local path
+    path="$*"
 
     # If the path begin with /, this is an absolute part
-    if [[ "$*" =~ ^/[[:graph:]]*$ ]]
+    if [[ "$path" =~ ^/[[:graph:]]*$ ]]
     then
-        repository="$(dirname $*)"
-        return
+        repository="$(dirname "$path")"
+        return 
     fi
 
-    local relative_path="$*"
-    local current_path="$(pwd)"
+    local relative_path
+    local current_path
+
+    current_path="$(pwd)"
+    relative_path="$path"
+
     while [[ $relative_path =~ ^../[[:graph:]]*$ ]]
     do
             printf "We found ..\n"
@@ -74,19 +90,22 @@ private:remove_symblink()
 {
     # Remove a symblink
     # $* source
+    
+    local source
+    source="$*"
 
     printf "  -> Remove symblink %s : " "$symblink"
-    if [ -L "$*" ]
+    if [ -L "$source" ]
     then
         local ret;
         ret=$(rm "$*" 2>&1)
         [ $? -ne 0 ] && { error "can't remove : $ret"; return; }
-    elif [ ! -f "$*" ]
+    elif [ ! -f "$source" ]
     then
-        error "$* not exist"
+        error "$source not exist"
         return
     else
-        error "$* is not a symblink"
+        error "$source is not a symblink"
     fi
     printf "\e[32mdone\e[0m\n"
 }
@@ -97,8 +116,11 @@ private:create_symblink ()
     # $1: source
     # $2: destination
 
-    local source="$1"
-    local dest="$2"
+    local source
+    local dest
+
+    source="$1"
+    dest="$2"
     
     printf "  -> Create a symblink from %s : " "$source"
 
@@ -116,11 +138,11 @@ private:create_symblink ()
                 error "can't overwrite destination"
                 return
             else
-                rm -rf $dest
+                rm -rf "$dest"
             fi
-        elif [ -e $dest ]
+        elif [ -e "$dest" ]
         then
-            error "destination exist but is not a directory"
+            error "destin ation exist but is not a directory"
             return
         fi
 
@@ -153,9 +175,15 @@ private:clone_repository ()
     # $1 url
     # $2 local repository
     # return : local directory
-
+    
+    local url
+    local repo
     local ret
-    ret=$(git clone -q "$1" "${2}" 2>&1)
+
+    url="$1"
+    repo="$2"
+
+    ret=$(git clone -q "$url" "$repo" 2>&1)
     [[ $? -ne 0 ]] && die "Can't clone_repository : $ret" 20 0
 }
 
@@ -164,15 +192,53 @@ private:update_repository ()
     # Update a git repository
     # $1 : local repository
     
-    [ ! -d "$1" ] && die "Git update : directory $1 does not exist" 25 0
-    local current_dir=$(pwd)
+    local repo
+    repo="$1"
+
+    [ ! -d "$repo" ] && die "Git update : directory $1 does not exist" 25 0
+    
+    local current_dir
     local ret
-    cd "$1"
+    
+    current_dir=$(pwd)
+
+    cd "$repo" || die "Can't go to directory ${repo}"
     ret=$(git pull 2>&1)
     [[ $? -ne 0 ]] && die "Can't update repository : $ret" 24 0
+    
+    cd "$current_dir" || die "Can't return to directory $current_dir"
 }
 
-process_dirs () {
+link_directory () {
+   
+   # Create a symblink to directory inside an other directory
+   #
+   # $1: source directory
+   # $2: destination directory
+
+    local source
+    source="$1"
+    local dest
+    dest="$2"
+    printf "\nProcess directory %s\n" "$source"
+    if [[ ! $source =~ ^$repository ]]
+    then
+	    echo "Add repo before source"
+	    source="${repository}/$source"
+    fi
+    [ ! -d "$source" ] && { error "  -> source is not a directory"; return; }
+    [ ! -d "$dest" ] && { error "  -> destination is not a directory"; return; }
+    
+    if [ $install -eq 1 ]
+    then
+        private:create_symblink "$source" "${dest}/$(basename "$d")"
+    else
+        local symblink="${dest}/$(basename "$d")"
+        private:remove_symblink "$symblink"
+    fi
+}
+
+link_directories () {
 
     # Process a directory than contains subdir, create symblink from each subdir
     # to the destination.
@@ -180,53 +246,60 @@ process_dirs () {
     # $1: source directory
     # $2: destination directory
 
-    local source="${repository}/$1"
-    local dest="$2"
+    local source
+    source="$1"
+    local dest
+    dest="$2"
     printf "\nProcess directory %s\n" "$source"
 
-    [ ! -d "$source" ] && { error "  -> source is not a directory"; return; }
-    [ ! -d "$dest" ] && { error "  -> destination is not a directory"; return; }
-
-    while read d
+    while read -r d
     do
-        if [ $install -eq 1 ]
-        then
-            private:create_symblink "$d" "${dest}/$(basename "$d")"
-        else
-            local symblink="${dest}/$(basename ${d})"
-            private:remove_symblink "$symblink"
-        fi
-
-    done < <(ls -d -1 "${source}"/*/)
+        link_directory "$d" "${dest}"
+    done < <(ls -d -1 "${repository}/${source}"/*/)
 }
 
-process_files () {
+process_dirs () {
+
+    printf "This function is deprecated, use link_directories instead.\n"
+    link_directories $@
+}
+
+link_files () {
 
     # Process a directory than contains config files, create symblink from each
     # files to the destination.
     # $1: source directory
     # $2: destination directory
     
-    local source="${repository}/$1"
-    local dest="$2"
-    printf "Process files from directory %s:\n" "$source"
+    local source
+    local dest
+
+    dest="$2"
+    source="${repository}/$1" 
+
+    printf "\nProcess files from directory %s:\n" "$source"
     
     [ ! -d "$source" ] && { error "  -> source is not a directory"; return; }
     [ ! -d "$dest" ] && { error "  -> destination is not a directory"; return; }
 
-    while read d
+    while read -r d
     do
         if [ $install -eq 1 ]
         then
             private:create_symblink "${source}/$d" "${dest}/$(basename "$d")"
         else
-            local symblink="${2}/$(basename ${d})"
+            local  symblink
+            symblink="${dest}/$(basename ${d})"
             private:remove_symblink "$symblink"
         fi
 
     done < <(ls -A -1 "$source")
 }
 
+process_files () {
+    printf "process_files is deprecated, use link_files instead\n"
+    link_files $@
+}
 
 install_service ()
 {
@@ -234,32 +307,43 @@ install_service ()
     # $1 file
     # $2 1 to Activate the service
 
-    local source="${repository}/$1"
+    local source
+    local activate
+    source="${repository}/$1"
+    activate=$2
+
+    [ -z "$activate" ] && activate=0
+
     local ret
     [ ! -f "$source" ] && { error "$1 not found"; return; }
-    local basename=$(basename "$source") 
+    
+    local basename
+    basename=$(basename "$source") 
+    
     if [ $install -eq 1 ]
     then
         printf "\nInstall service %s :\n" "$source"
         private:create_symblink "$source" "${SYD_DIRECTORY}/${basename}"
 
         # activate service
-        if [ $2 ]
+        if [ $activate -eq 1 ]
         then
-            printf "  -> Activate $basename : "
-            ret=$(systemctl --user enable ${basename} 2>&1)
-            [[ $? -ne 0 || ! $(systemctl --user is-enabled $basename) ]] && { error "$ret"; return; }
+            printf "  -> Activate %s :" "$basename"
+            ret=$(systemctl --user enable "${basename}" 2>&1)
+            [[ $? -ne 0 || ! $(systemctl --user is-enabled "$basename") ]] && { error "$ret"; return; }
             printf "\e[32mdone\e[0m\n"
         fi
     else
         printf "\nUninstall service %s :\n" "$source"
         #Deactivate service
-        if [ $1 ]
+        if [ $activate -eq 1 ]
         then
-            printf "    -> Deactivate $basename : "
-            ret=$(systemctl --user disable ${basename} 2>&1)
+            printf "   -> Deactivate %s : " "$basename"
+            ret=$(systemctl --user disable "${basename}" 2>&1)
             [[ $? -ne 0 ]] && { error "$ret"; return; }
             printf "\e[32mdone\e[0m\n"
+        else
+            private:remove_symblink "${SYD_DIRECTORY}/${basename}"
         fi
     fi
 
@@ -269,14 +353,17 @@ required_commands ()
 {
     # Check if an executable exist
     # $1 executables separated with spaces
+    
+    local bins
+    bins="$*"
 
     # if uninstall, we don't need to process required commands.
     [ $install -eq 0 ] && return
     printf "Checking required programs :\n"
-    for p in $1
+    for bin in $bins
     do
-        printf "  -> %s:" "$p"
-        command -v $p >/dev/null 2>&1 || die "not found" 128
+        printf "  -> %s:" "$bin"
+        command -v "$bin" >/dev/null 2>&1 || die "not found" 128
         printf " \e[32mfound\e[0m\n"
     done
 }
@@ -287,8 +374,10 @@ install_bin ()
     # Via a symbolic link
     # $1 : path to script
 
-    local source="${repository}/${1}"
-    local dest="${BIN_DIRECTORY}/$(basename $1)"
+    local source
+    source="${repository}/${1}"
+    local dest
+    dest="${BIN_DIRECTORY}/$(basename "$1")"
     
     printf "\nProcess executable :\n"
     [ ! -f "$source" ] && { error "$source is not a file"; return; }
@@ -308,21 +397,27 @@ define_env ()
     # on uninstall mode
     # $1 variable name
     # $2 value
+    local name
+    local value
+
+    name="$1"
+    value="$2"
+
+    [ -z "$name" ] && { error "You must define a name"; return; }
+    [ ! -f "$ENV_FILE" ] && touch "$ENV_FILE"
 
-    [ -z $1 ] && { error "You must define a name"; return; }
-    [ ! -f $ENV_FILE ] && touch $ENV_FILE
     if [ $install -eq 1 ]
     then
-        printf "\nCreate an environment variable %s : " "$1"
-        [ $(grep -c -m 1 $1 $ENV_FILE) -eq 1 ] && { error "already exist"; return; }
+        printf "\nCreate an environment variable %s : " "$name"
+        [ $(grep -c -m 1 "$name" "$ENV_FILE") -eq 1 ] && { error "already exist"; return; }
         local line
-        line="export ${1}=\"${2}\""
-        echo "$line" >> $ENV_FILE
+        line="export ${name}=\"${value}\""
+        echo "$line" >> "$ENV_FILE"
         printf "\e[32mdone\e[0m\n"
     else
-        printf "\nRemove an environment variable %s : " "$1"
-        [ $(grep -c -m 1 $1 $ENV_FILE) -eq 0 ] && { error "not exist"; return; }
-        sed -i "/^export $1=*/d" $ENV_FILE
+        printf "\nRemove an environ ment variable %s : " "$1"
+        [ $(grep -c -m 1 "$1" "$ENV_FILE") -eq 0 ] && { error "not exist"; return; }
+        sed -i "/^export $1=*/d" "$ENV_FILE"
         printf "\e[32mdone\e[0m\n"
 
     fi
@@ -351,10 +446,10 @@ esac
 
 if [[ $* =~ ^https://.*\.git$ || $* =~ ^ssh://.*\.git$ ]]
 then
-    check_bin "git"
+    required_commands "git"
     
     # Check
-    localrepo="${DOTREPO}/$(basename $* .git)"
+    localrepo="${DOTREPO}/$(basename "$*" .git)"
     if [ $update -eq 1 ]
     then
         private:update_repository "$localrepo"
@@ -362,7 +457,7 @@ then
         if [ $install -eq 1 ]
         then
             private:clone_repository "$*" "$localrepo"
-        fi
+        fi 
     fi
     bootstrap_file="${localrepo}/bootstrap"
 else
@@ -372,23 +467,22 @@ fi
 [ ! -f "$bootstrap_file" ] && die "$bootstrap_file does not exist" 2 1
 
 private:get_bootstrap_path "$bootstrap_file"
-cache_file="${CACHE_DIR}/$(echo $repository | tr '/' '_')"
+cache_file="${CACHE_DIR}/$(echo "$repository" | tr '/' '_')"
 
 if [ $update -eq 1 ]
 then
     # Update mode
-    if [ -f "$cache_file" ]
+    if [ -f "$cache_file" ] 
     then
-        if [ $(diff "$bootstrap_file" "$cache_file" > /dev/null; echo $?;) -eq 0 ]
+        if [ $(diff "$bootst rap_file" "$cache_file" > /dev/null; echo $?;) -eq 0 ]
         then
-            printf "There is no difference between cached copy and the bootstrap file\n";
+            printf "There is  no difference between cached copy and the bootstrap file\n";
             exit 0
         else
             # for updating the dotfile repo, we need to uninstall it then 
             # install it. We need the cached copy for unistall.
-            install=0
+            install=0 
             source "$cache_file"
-            rm "$cache_file"
             install=1
         fi
     else
@@ -405,8 +499,7 @@ source "$bootstrap_file"
 if [ $install -eq 0 ]
 then
     printf "\nRemove files for complete uninstall\n"
-    rm $cache_file
-    rm -rf $repository
+    rm "$cache_file"
 fi
 
 exit 0