./shell.sh: line 6: [: =~: binary operator expected

Question

I'm trying to execute the following shell script, where I'm trying to keep executing a command in an infinite loop and until the output is not equal to a certain substring

checkDeviceStatus=$(adb shell getprop sys.boot_completed 2>&1)

function Check_Status () {

while [ ! "$checkDeviceStatus" =~ "device offline" ] || [ ! "$checkDeviceStatus" =~ "device still authorizing" ]
  do
  if [ ! "$checkDeviceStatus" =~ "device offline" ] || [ ! "$checkDeviceStatus" =~ "device still authorizing" ];
       then
          echo "Device is now up and running!!: '$checkDeviceStatus'"
          break
       else 
            echo "'$checkDeviceStatus'"
       fi;
done

};

Check_Status

but I'm getting the following error

./shell.sh: line 6: [: =~: binary operator expected
./shell.sh: line 8: [: =~: binary operator expected

`shellcheck.net` is your friend. In this case, =~ is only recognised within `[[ ... ]]` brackets. — Paul_Pedant, Jul 19 '21 at 14:48
`[` and `[[` are not the same thing, see e.g. [Why is `[` a shell builtin and `[[` a shell keyword?](https://unix.stackexchange.com/questions/183745/why-is-a-shell-builtin-and-a-shell-keyword) and [What is the difference between the Bash operators [[ vs [ vs ( vs ((?](https://unix.stackexchange.com/q/306111/170373) and http://mywiki.wooledge.org/BashGuide/TestsAndConditionals — ilkkachu, Jul 19 '21 at 14:51
also, before you trip on that, the assignment `checkDeviceStatus=$(adb shell getprop sys.boot_completed 2>&1)` runs the command and saves the output just _once_, it doesn't update every time you access the variable. So having the same condition in the `if` as in the surrounding `while` is a bit redundant, and also the loop condition will never change. You need to do the command substitution and assignment inside the loop to update it — ilkkachu, Jul 19 '21 at 14:54

score 0 · Accepted Answer · answered Jul 19 '21 at 15:28

#!/bin/bash

function Check_Status () {

while [[ "$(adb shell getprop sys.boot_completed 2>&1)" =~ "device offline" ]] || [[ "$(adb shell getprop sys.boot_completed 2>&1)" =~ "device still authorizing" ]] || [[  "$(adb shell getprop sys.boot_completed 2>&1)" =~ "no devices/emulators found" ]];
  do
  sleep 1
  if [[ "$(adb shell getprop sys.boot_completed 2>&1)" == "" ]] || [[ "$(adb shell getprop sys.boot_completed 2>&1)" == 1 ]];
  then 
     echo "Device is now up and running!!: '$(adb shell getprop sys.boot_completed 2>&1)'"
     break      
  else 
     echo "'$(adb shell getprop sys.boot_completed 2>&1)':("
  fi    
done

};

Check_Status

./shell.sh: line 6: [: =~: binary operator expected

1 Answers1