Why does root not have /usr/local in path

pathroot

I've noticed that the default path for root on my of my vm's and servers do not include /usr/local/bin

sudo -s  
echo $PATH
/sbin:/bin:/usr/sbin:/usr/bin

Whereas normal users on the server do have /usr/local/bin

/usr/local/bin:/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/sbin:/home/sowen/bin

Why would root not need /usr/local in the path?

Where is the default path for a user defined?

Best Answer

Because it isn't set up in the relevant shell startup files for root.

Traditionally, /usr/local has been used for unofficial, locally installed software (often to override buggy/broken/limited "official" versions; a friend quipped that the first step when a new Sun arrived was GNU > /usr/local). As root is all-powerful, any mistake or misdesign in the programs it runs can be fatal. It stands to reason that running e.g. a local, experimental version of make by root should be treated with caution. Better have it go the extra step of giving an explicit path.

Related Solutions

zsh variable path array – Difference Between $path and $PATH in zsh

That's a feature of zsh inherited from csh/tcsh.

The $path array variable is tied to the $PATH scalar (string) variable. Any modification on one is reflected in the other.

In zsh (contrary to (t)csh), you can tie other variables beside $PATH with typeset -T. It's conventional, but not mandatory, to use an uppercase name for the colon-separated scalar and the same name in lowercase for the array. While colon is the default separator, other separators can be used (for instance newline to tie a multi-line string to an array, or comma to tie a csv row to an array)

In recent versions of zsh, typeset -p PATH or typeset -p path shows the link between the two variables:

% typeset -p path
typeset -aT PATH path=( /home/chazelas/bin /usr/local/bin /usr/bin /bin )

That's useful in that it makes it easier to add remove components or loop over them.

Doing a typeset -U path to make the elements unique also helps keeping the $PATH variable clean (something similar can be achieved in tcsh with set -f).

Best Answer

Related Solutions

zsh variable path array – Difference Between $path and $PATH in zsh

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