How to tail output from adb logcat and execute a command each new line

Question

I'm trying to do very likely to this post but instead of reading from a file I want to "subscribe" to the output of adb logcat and every time a new line is logged I will run some code on this line.

I tried these codes, but none worked

tail -f $(adb logcat) | while read; do 
    echo $read;
    processLine $read;
done

or

adb logcat >> logcat.txt &
tail -f logcat.txt | while read; do 
    echo $read;
    processLine $read;
done

What is the simples way to do this? Thanks in advance

Answer 1

The following two solutions should work. I generally prefer the second form as the wile loop is run in the current process and so I can use local variables. The first form runs the while loop in a child process.

While loop in child process:

#!/bin/bash

adb logcat |
while read -r line; do
  echo "${line}"
  processLine "${line}"
done

While loop in current process:

#!/bin/bash

while read -r line; do
  echo "${line}"
  processLine "${line}"
done < <(adb logcat)