Ubuntu – How to suppress GtkDialog warnings in zenity and yad using Bash redirection in a script

bashcommand lineredirect

I'm trying to suppress GtkDialog warnings in zenity and yad:

$ zenity --error --text hello
Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged.

Error redirection and filtering works:

$ zenity --error --text hello 2> >(grep -v GtkDialog >&2)

YEAH… Annoying warning message disappears!!

This can be placed in ~/.bashrc for development work as answered here:

and here:

When creating a script for others to use though, you don't want the burden of them changing their ~/.bashrc.

I'm having trouble creating a typing shortcut for: 2> >(grep -v GtkDialog >&2) to be used inside script.

For many reasons variable assignment GTK_SPAM="2> >(grep -v GtkDialog >&2)" followed later by variable usage "$GTK_SPAM" doesn't work.

alias zenity="zenity 2> >(grep -v GtkDialog >&2)" before calling script works but, I can't use this within a script.

Using an array to hold the typing shortcut isn't working:

$ aGtkSpam=(2\> \>\(grep -v GtkDialog \>\&2\))

$ DumpArray "${aGtkSpam[@]}"
Array Elements:
0: 2>
1: >(grep
2: -v
3: GtkDialog
4: >&2)

$ zenity --error --text hello "${aGtkSpam[@]}"
This option is not available. Please see --help for all possible usages.

$ yad --text hello 2> >(grep -v GtkDialog >&2)

$ yad --text hello "${aGtkSpam[@]}"
Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged.

I found many excellent generic answers on word-splitting and parameters which should solve my problem but a specific syntax eludes me.

Any clues?

Best Answer

I don't think syntax alone can help you here - because of the order in which the shell sets up redirections and expands variables. To give a very simple illustration:

$ arr=( ">" "/dev/null" )
$ set -x
$ echo foo "${arr[@]}"
+ echo foo '>' /dev/null
foo > /dev/null

i.e. everything has been expanded "correctly", but > /dev/null has simply become a list of string arguments passed to echo.

You could force evaluation using eval:

$ eval echo foo "${arr[@]}"
+ eval echo foo '>' /dev/null
++ echo foo

but really it would be better to redirect the stream for the duration of your script using exec:

exec 2> >(grep -v GtkDialog >&2)

or, if you want to be able to turn the filter off before the end of the script, then based on After using exec 1>file, how can I stop this redirection of the STDOUT to file and restore the normal operation of STDOUT? it should be possible to do 

exec 3>&2 2> >(grep -v GtkDialog >&2)

and then later

exec 2>&3 3>&-

to recover the duplicated stream.

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