0

Let's say I have the following export in my ~/.bashrc

export MODE=vanilla
export PATH=/opt/bin/:/usr/bin/

And two scripts in my home

cat ~/setup_foo.sh
export MODE=foo
export PI_NUMBER=4
export PATH=/opt/bin/tool_foo/:$PATH

cat ~/setup_boo.sh
export MODE=boo
export PI_NUMBER=3
export PATH=/opt/bin/tool_boo:$PATH

The functionality I want to have:

$ echo $MODE
vanilla
echo $PATH
/opt/bin/:/usr/bin/

$ <<activate_foo>>
echo $MODE
foo
echo $PATH
/opt/bin/tool_foo/:/opt/bin/:/usr/bin/


$ <<activate_boo>>
echo $MODE
boo
echo $PATH
/opt/bin/tool_boo:/opt/bin/:/usr/bin/        --- NOTE, NO FOO HERE PRESERVED!


$ <<back_to_normal>>
echo $MODE
vanialla
echo $PATH
/opt/bin/:/usr/bin/    --- NO FOO AND BOO HERE!

What sort of tools, packages, bash should I use intsead of << pseudo commands >> ?

If I just call ~/.setup_foo.sh it will overwrite variable, but do not clean up PATH

Konstantin Vinogradov
  • 1

2 Answers2

1

Probably the simplest thing is to start a new bash shell and source the setup file, then exit from the shell to get back to your previous environment. Ex.:

$ printenv grep '[bf]oo'

$ bash --rcfile setup_foo.sh
$ printenv | grep '[bf]oo'
MODE=foo
PATH=/opt/bin/tool_foo/:/home/steeldriver/bin:/home/steeldriver/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin


$ exit
exit
$ printenv grep '[bf]oo'


$ bash --rcfile setup_boo.sh
$ printenv | grep '[bf]oo'
MODE=boo
PATH=/opt/bin/tool_boo:/home/steeldriver/bin:/home/steeldriver/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin


$ exit
exit
$ printenv grep '[bf]oo'
steeldriver
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  • you could also combine/concat files --rcfile <(cat ~/.profile setup.sh) –  Oct 13 '20 at 14:25
0

By deleting old entries first, you can prevent them from appearing multiple times.

#!/bin/bash

NEW_PATH=/opt/bin
PATH=$NEW_PATH:${PATH//$NEW_PATH:/}
echo $PATH


And to remove your entry completely.


PATH=${PATH//$NEW_PATH:/}
echo $PATH

Another example using extglob list to handle multiple paths at once.

#!/bin/bash

shopt -s extglob


FOO_PATH=/opt/foo
BAR_PATH=/opt/bar


PATH=$FOO_PATH:$BAR_PATH:${PATH//@($FOO_PATH|$BAR_PATH):/}