How to use zenity file selection

Solution 1:

In order to save the output of a command in a variable, you must enclose the command in backtics (`command`) or, better, in $() ($(command)). You are using single quotes which means that you are saving the string wc $FILE and not actually running wc:

$ foo='wc /etc/fstab' ## WRONG
$ echo $foo
wc /etc/fstab

$ foo=`wc /etc/fstab`  ## RIGHT
$ echo $foo 
23 96 994 /etc/fstab

$ foo=$(wc /etc/fstab)   ## RIGHT
$ echo $foo 
23 96 994 /etc/fstab

In addition, in order to get only the words and not the number of characters and lines, use the -w option:

$ foo=$(wc -w /etc/fstab)   
$ echo $foo 
96 /etc/fstab

Finally, to get the number alone, with no file name, you can use:

$ foo $(wc -w /etc/fstab | cut -d ' ' -f 1 )
$ echo $foo
96

Solution 2:

I think that the correct code may be this:

#!/bin/bash

function count() {
  word_count=$(wc -w < "$FILE")
  zenity --info --title="Word Counted" --text="Counted words $word_count"
}

function choose() {
  FILE="$(zenity --file-selection --title='Select a File')"
  case $? in
           0)
                  count;;
           1)
                  zenity --question \
                         --title="Word counter" \
                         --text="No file selected. Do you want to select one?" \
                         && choose || exit;;
          -1)
                  echo "An unexpected error has occurred."; exit;;
  esac
}

choose