fish: add envsource function for exporting environment variables

user/fish/default.nix

@@ -35,6 +35,14 @@ in
         set_color normal
 
         bind \cy 'commandline | wl-copy -n'
+
+        function envsource
+          for line in (cat $argv | grep -v '^#' |  grep -v '^\s*$' | sed -e 's/=/ /' -e "s/'//g" -e 's/"//g' )
+            set export (string split ' ' $line)
+            set -gx $export[1] $export[2]
+            echo "Exported key $export[1]"
+          end
+        end
       '';
       shellAliases = {
         rm = "trash";