Specifying PS4 when using the -x flag can be even more helpful while debugging. The variable PS4 denotes the value is the prompt printed before the command lin

Specifying PS4 when using the -x flag can be even more helpful while debugging. The variable PS4 denotes the value is the prompt printed before the command line is echoed when the -x option is set and defaults to : followed by space. A number of useful debugging tips are listed at <https://wiki.bash-hackers.org/scripting/debuggingtips https://wiki.bash-hackers.org/scripting/debuggingtips>.