logcat cant find tag code example

Example 1: logcat android

Logcat is a command-line tool that dumps a log of system messages, 
including stack traces when the device throws an error and messages 
that you have written from your app with the Log class.

Example 2: android logs for app on terminal

adb logcat | grep -F "`adb shell ps | grep com.asanayoga.asanarebel  | tr -s [:space:] ' ' | cut -d' ' -f2`"