Re: Bash and the PS1 environment variable [was: grep: show matching line from pattern file]
On Thu, Jun 02, 2022 at 06:01:11PM -0700, David Christensen wrote:
> This is my PS1. '\u' does not work on all of Debian, FreeBSD, Cygwin, and
> macOS, so the expansion of ${USER} is inserted between two string literals
> when .profile runs and sets PS1:
>
> 2022-06-02 17:39:09 dpchrist@laalaa ~
> $ grep PS1 .profile
> export PS1='\n\D{%Y-%m-%d %H:%M:%S} '${USER}'@\h \w\n\$ '
Variable expansions *are* performed when PS1 is evaluated. So, you
could simply do:
PS1='stuff $USER more stuff'
That will delay the expansion of USER (which by the way is a BSD-ism)
until the prompt is drawn. The way you've written it, $USER is
expanded at the time PS1 is assigned. Which is not wrong, so long as
the value of USER cannot change in the middle of a shell session...
but it's not how most of the experienced people would do it, I think.
I'm rather curious how you managed to find a system + bash version
where \u doesn't work. That sounds like something you'd want to report
to the bug-bash mailing list... or, possibly, a user error. \u should
work on any Unix-like system.
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