Question

I wish to show exit code on Bash shell prompt, so that I can easily know whether the previous command run successfully, however, it always show 0. Anything wrong with this? Then is it possible to accomplish the desired result?

 PS1="\t <\w> ERR:$(echo $?) \$ "

— Bash 4.1.10 on openSUSE 11.4

Answer 1

You forgot to escape the $ in order to inhibit expansion when the assignment is executed.

PS1="\t <\w> ERR:$(echo \$?) \$ "

​

22:04:48 <~/Work/tmp> ERR:x $ true
22:05:51 <~/Work/tmp> ERR:0 $ false
22:05:52 <~/Work/tmp> ERR:1 $