My quest for the ultimate Bash prompt

On my new laptop (a Lenovo T61) I was still using the default Gentoo prompt in Bash. This was kind of a shame since my last Gentoo installation (on what is now my sister’s Ubuntu machine) had a beautifully customized prompt. It was time to dig up the old escape codes.

The old

To recover my old prompt I didn’t even need to go rummaging through old files. All I had to do was to find an old forum post on the Gentoo forums. But, I noticed immediately that I didn’t like this old prompt so much anymore. It had too much stuff and it didn’t have very strong root warning signals.

My old Bash prompt

My old Bash prompt as root

The new

My new Bash prompt

For my new prompt I used the PROMPT_COMMAND environment variable. The command in this environment variable is always run before the prompt is displayed. This means that, if you set the PS1 environment variable from this command, you can change your prompt depending on circumstances.

I pushed the dollar (or hash)-sign all the way to the left because I often type in very long commands. A little more space is used if there are background jobs, but only if there are background jobs.

My new Bash prompt with background jobs

You should never be root for too long, so I made being root very noticeable (and even slightly annoying):

My new Bash prompt as root (and with background jobs)

The following is the code I use to create the prompt. Stick it wherever you want it (e.g. in your user’s bashrc or in the system-wide bashrc) and adjust it to look nice and play nice with the rest of your environment. The code isn’t pretty, but it does what it has to. 😉

prompt_command {
  XTERM_TITLE="\e]2;\u@\H:\w\a"
 
  BGJOBS_COLOR="\[\e[1;30m\]"
  BGJOBS=""
  [ "$(jobs | head -c1)" ]; BGJOBS=" $BGJOBS_COLOR(bg:\j)";
 
  DOLLAR_COLOR="\[\e[1;32m\]"
  [[ ${EUID} == 0 ]] ; DOLLAR_COLOR="\[\e[1;31m\]";
  DOLLAR="$DOLLAR_COLOR\\\$"
 
  USER_COLOR="\[\e[1;32m\]"
  [[ ${EUID} == 0 ]]; USER_COLOR="\[\e[41;1;32m\]";
 
  PS1="$XTERM_TITLE$USER_COLOR\u\[\e[1;32m\]@\H:\[\e[m\] \[\e[1;34m\]\w\[\e[m\]\n\
$DOLLAR$BGJOBS \[\e[m\]"
} PROMPT_COMMAND=prompt_command

More info

If you want to learn more about customizing your prompt, there’s an article up at IBM’s website. From it, I stole this nice color table:

Console color codes table

Another tip: you can type man console_codes for everything about … console codes.