- added helper method to look up wether a command exists

- avoid calling flatpak or notify-send if not installed

home_external/.bash_aliases

@@ -40,6 +40,11 @@ alias dirsizes='du -kh --apparent-size --max-depth=1 | sort -hr'
 alias start_x11_vnc="x11vnc -many -display :0 -no6 -rfbport 5900 -auth /var/run/lightdm/root/:0 -rfbauth $HOME/.vnc/passwd"
 
 
+commandExists() {
+   type $1 2 >& 1 > /dev/null
+}
+
+
 rsyncLink() {
    source=$1;
    linkSource="$(realpath $source)";
@@ -63,6 +68,9 @@ doUpdateSystem() {
 
 
 updateFlatpak() {
+   if [[ ! $(commandExists flatpak) ]]; then
+      return 1;
+   fi
    noconfirm=
    if [[ $1 == "-y" ]]; then
       noconfirm="--assumeyes";
@@ -119,11 +127,19 @@ finds () {
 
 # sends a desktop-notification with an icon signalling an error
 notifyError () {
+   if [[ ! $(commandExists notify-send) ]]; then
+      echo "ERROR: $1";
+   else
       notify-send "$1" --icon=data-warning;
+   fi
 }
 
 
 # sends a desktop-notification with an icon signalling a simple information
 notifyInfo () {
+   if [[ ! $(commandExists notify-send) ]]; then
+      echo "INFO: $1";
+   else
       notify-send "$1" --icon=preferences-desktop-notification;
+   fi
 }