shell - Why zenity color selection piping to sed breaks the code? -

i trying use sed convert 12 digit hex code returned zenity's --color-selection dialogue 6 digit hex code. example: #dfe251a951a9 #df5151. use sed in following code breaks whole script, , when select "select" or "cancel" buttons dont respective echo! what's problem?

before using sed: works nice 12 digit hex code.

#!/bin/bash color=$(zenity --color-selection) if [[ $? == 0 ]]      echo "you selected $color." else [[ $? == 1 ]]     echo "no color selected." fi 

after using sed: when hit select button 6 digit hex code when hit cancel dont "no color selected", echoes "you selected ."

#!/bin/bash color=$(zenity --color-selection | sed 's/\(#\?..\)../\1/g') if [[ $? == 0 ]]      echo "you selected $color." else [[ $? == 1 ]]     echo "no color selected." fi 

after

color=$(zenity --color-selection | sed 's/\(#\?..\)../\1/g') 

$? exit status of sed (not zenity)¹, 0. use

#!/bin/bash color=$(zenity --color-selection)  # $? exit status of zenity if [[ $? == 0 ]]     # process sed if necessary.     color=$(echo "$color" | sed 's/\(#\?..\)../\1/g')     echo "you selected $color" else     echo "no color selected." fi 

note, way, version of zenity (3.16.2) not return hexadecimal code of form rgb(12,34,56). have not investigated when or why change happened, may not wise rely on particular format.

¹ more precisely: it's exit status of subshell spawned $(), forwards exit status of last command ran: sed call.