CODEWITHSUNDEEP
bash
ptkvsk
ptkvsk

Reputation: 2222

Run script in a clean environment

Let's say I have a script install.sh. I want to put a command at the beginning of this script that will clean the environment for me, keeping only $PATH and $HOME of a parent shell.

I know about env -i but it requires a second script which will do "env -i install.sh". I want a single install.sh script which users will run directly ("sh install.sh" or "./install.sh").

Upvotes: 0

Views: 618

Answers (2)

Toby Speight
Toby Speight

Reputation: 30841

One way to do this is to use compgen -v to give a list of variable names, and unset each in turn:

for i in $(compgen -v)
do
    case "$i" in
      HOME|PATH)
        ;;
      *)
        unset "$i"
        ;;
    esac
done
unset i

Note that there are some Bash variables which can't be unset:

  • BASHOPTS
  • BASH_ARGC
  • BASH_ARGV
  • BASH_LINENO
  • BASH_SOURCE
  • BASH_VERSINFO
  • EUID
  • PIPESTATUS
  • PPID
  • SHELLOPTS
  • UID
  • _

Upvotes: 1

muru
muru

Reputation: 4897

You can re-exec the script from within it:

[ -z "$CLEANED" ] && exec env -i CLEANED=1 "PATH=$PATH" "HOME=$HOME" bash "$0" "$@"
unset CLEANED

Where CLEANED is a marker variable to tell your script that the environment has been cleaned.

Upvotes: 3

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