On Wednesday 03 January 2007 09:00, Gregor Schneider wrote:
> Hi guys,
>
> just a short question:
>
> After installing Edge, I see the common-user-$PS1 as follows:
>
> ${debian_chroot:+($debian_chroot)}\u@\h:\w\$
>
> I understand \u@\h:\w\$, however, what does
>
> ${debian_chroot:+($debian_chroot)}
>
> do?
From the bash manpage under the "Parameter Expansion" section:
${parameter:+word}
Use Alternate Value. If parameter is null or
unset, nothing is substituted, otherwise the
expansion of word is substituted.
Basically, this is to show info about the current chroot you are in. This is
useful for when you have various chroots (say for different debian
versions, etc).
The value gets pulled from the environment, or from /etc/debian_chroot. See
this part of /etc/bash.bashrc:
# set variable identifying the chroot you work in (used in the prompt below)
if [ -z "$debian_chroot" ] && [ -r /etc/debian_chroot ]; then
debian_chroot=$(cat /etc/debian_chroot)
fi
--
Wesley J. Landaker <wjl@icecavern.net> <xmpp:wjl@icecavern.net>
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