sudo extends ~ to /root

[mitnk]

Hi everyone,

I am write some bash code like this:

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echo ${XYZ:-~/.vimrc}

saved as foo.sh and I run it with:

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sudo ./foo.sh

When I run at Raspbian, I got:

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/root/.vimrc

(What I expected was: /home/pi/.vimrc)

But at other OS (Ubuntu and OS X), I got this (mitnk is my username):

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/home/mitnk/.vimrc

The OS info:

PRETTY_NAME="Raspbian GNU/Linux 8 (jessie)"
NAME="Raspbian GNU/Linux"
VERSION_ID="8"
VERSION="8 (jessie)"

Can anyone explain why it's not `/home/pi/.vimrc`? Thanks.

[disorientedp]

Try ~pi/otherstuff instead of ~/otherstuff.

[disorientedp]

The root home directory (which is what commands are run through with sudo) is different than other home directories.

[QuietZone]

The real answer to this question is that it is, as you've observed, kind of a dark corner.

Like you, I've seen it behave differently on different versions of Unix/different distros of Linux, etc. You just have to accept it.

The exact semantics of "su" have never really been nailed down.

[mitnk]

Thanks @disorientedp and @QuietZone for the tips / informations.

[jojopi]

To preserve ~/ in non-login sessions started via sudo, add to /etc/sudoers using sudo visudo:

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Defaults        env_keep += "HOME"

I personally like this configuration, but some regard it as having security implications. Also it definitely increases the risk that configuration files under /home/pi/ will be created with root ownership, so you should be comfortable with managing permissions before enabling it.