Why is this bash prompt acting strangely/disappearing, and how do I fix it (OS X)?

Question

I admit that I use a somewhat long-winded bash prompt:

--(username)-(Wed April 01|12:00:00)--(~ $

Recently, I got the bright idea to change

Answer 1

It sounds like this should solve your problem.

This seems to work for me*:

export PS1='--(\[\e[$((32-${?}))m\]\u\[\e[0m\])-(\[\e[$((32-${?}))m\]\d\[\e[0m\]|\[\e[$((32-${?}))m\]\T\[\e[0m\])--(\[\e[$((32-${?}))m\]\w\[\e[0m\] \$ '

* well, really export PS1='\u@\h:\w\$ ' works for me

To quote the linked post, the answer lies in adding \[ and \] around all of your color sequences in your PS1 declaration:

Before I had the following value for PS1:

'\e[0;34m\h:\w [!]\$\e[0m '

which gave me a nice blue prompt of the following form

hostname:working-directory [command-number]$

However, I had the same line-wrapping problem you did. The fix was to insert \[ and \] around the ANSI escapes so that the shell knows not to include them in the line wrapping calculation. This results in the following value for PS1:

'\[\e[0;34m\]\h:\w [!]\$\[\e[m\] '

Answer 2

http://mywiki.wooledge.org/BashFAQ/053 -- I have a fancy prompt with colors, and now bash doesn't seem to know how wide my terminal is. Lines wrap around incorrectly.

By the way; for your reference; here's my PS1 which looks like this:
_{(source: lyndir.com)}

\[$reset$bold$green\]\u@\h\[$blue\] \W \[$red\]${?/#0/\[$green\]}\$\[$reset\]

Notice how I put all the color codes in $parameters to make it neater, but more importantly, because you should be using tput to generate them. See:

http://mywiki.wooledge.org/BashFAQ/037 -- How can I print text in various colors?

I declare my color parameters in a utility script that gets sourced by my ~/.bashrc (and any scripts I write) which is called bashlib.

On a final note; put your PS1 definition in ~/.bashrc and don't export it. There's absolutely no reason why you should add your PS1 definition to the environment of any and all processes you spawn from your shell.

Answer 3

You just seem to be missing the start and end brackets around your escapes (before the first '\e' and after the last 'm'):

PS1='--(\[\e[$((32-${?}))m\u\e[0m)-(\e[$((32-${?}))m\d\e[0m|\e[$((32-${?}))m\T\e[0m)--(\e[$((32-${?}))m\w\e[0m\] \$ '

As mentioned, the PS1 var does not need to be exported: only your shell needs to see it.