CODEWITHSUNDEEP
bashoutput
Cameron Ball
Cameron Ball

Reputation: 4108

Echo output of linux dialog utlity in bash script

I'm working on a simple bash script menu, and I've followed this guide to get started.

It works fine, but I don't really like how stderr is redirected to a file and then used in the main loop.

In my script I have a few functions that draw different things. I'm trying to modify them to work without having to write to the files. One of the functions to draw a menu looks like th is (simplified):

function render_menu()
{
    dialog --clear --backtitle "$backtitle" --title "Some Title" --menu "My  fancy menu" 50 15 4 "one" "option 1" "two" "option 2"
    echo $?
}

And it is called from the main loop like:

while true; do
    selection="$(render_menu)" 

    case $selection in
            Quit) break;;
            Back) #some logic;;
            *) #some logic;;
    esac
done

But it doesn't work, when I run the script I don't see the menu. I assume because the output of dialog has been redirected?

The way I want it to work is that the dialog is displayed, and the output from it is stored in the variable selection. Is that possible without the need for an external file? If not, why so?

Upvotes: 0

Views: 1500

Answers (1)

pasaba por aqui
pasaba por aqui

Reputation: 3519

Try as:

#!/bin/bash
#

function render_menu()
{
  exec 3>&1
  selection=$(dialog --clear --backtitle "$backtitle" --title "Some Title" --menu "My  fancy menu" 50 15 4 "one" "option 1" "two" "option 2" 2>&1 1>&3)
  exit_code=$?
  exec 3>&-
}

render_menu 
echo $exit_code
echo $selection

*** Addendum 1 ***

If, for some reason, the function must be called as $(render_menu ...) and return result in stdout, this is another possibility:

#!/bin/bash 
#

function render_menu()
{
   selection=$(dialog --clear --backtitle "$backtitle" --title "Some Title" --menu "My  fancy menu" 50 15 4 "one" "option 1" "two" "option 2" 2>&1 1>&3)
  exit_code=$?
   echo $selection
}

exec 3>&1
selection="$(render_menu  2>&1 1>&3)"
exec 3>&-
echo $selection

Upvotes: 1

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