Many people don’t think of their command prompt as a particularly useful thing, or even pay it much attention. To me, this is a bit of a shame, as a useful prompt can change the way you use the command line. Well I’ve scoured the Interwebs looking for the best, most useful, or sometimes most amusing bash prompts. Here, in no particular order, are the ones I’d be most likely to use on my computers.
1. Show Happy face upon successful execution
This prompt is probably the most amusing one on the list, but remains useful. The idea is that as long as your commands execute successfully, your prompt shows a happy face. Any time a command fails, it shows a sad face instead.
PS1="\`if [ \$? = 0 ]; then echo \[\e[33m\]^_^\[\e[0m\]; else echo \[\e[31m\]O_O\[\e[0m\]; fi\`[\u@\h:\w]\\$ "
2.Change color on bad command
Here’s one of my favorites. This prompt has it all. Like above, the prompt changes color if your last command failed to run successfully, but it also shortens long paths and contains the bash history number of each command for easy retrieval.
rest here