CODEWITHSUNDEEP
bashenvironment-variables
Andrea Spadaccini
Andrea Spadaccini

Reputation: 12651

Getting external PS1 value inside bash script

I need to get the value of the PS1 variable inside a bash script.

I know that running the script with a dot before makes bash pass env variables to the script, but I need to get PS1 regardless of how it is invoked, since I don't trust who will run the script.

How do I get it?

Update: the variable has been exported in /etc/profile, but I cannot get it:

[ Test ] root@myhost:~# export | grep PS1
declare -x PS1="[ Test ] \\u@\\h:\\w\\\$ "
[ Test ] root@myhost:~# cat test.sh 
echo $PS1
[ Test ] root@myhost:~# bash test.sh

I get no output from the last command.

Upvotes: 2

Views: 3768

Answers (3)

user5765317
user5765317

Reputation: 39

5 years later....because i used the following solution after finding this question.

If you want you can use the -i flag in the header and it seems to keep the environment during the script without having to run it in a special manner. I.e.

#!/bin/bash -i
echo "$PS1"

I don't know if this has any other weird behaviors, but it worked for what I needed.

Upvotes: 3

Mark
Mark

Reputation: 562

Start your test script with 'bash -i'; this makes it behave like a login shell and (amongst other things) sets PS1.

If your script will be run as an executable (.e.g ./test.sh) then you can also provide -i on the initial line, like this:

#!/bin/bash -i

Update: This only works if your script is executed directly, e.g.

$ ./test.sh

and not as:

$ bash test.sh

as that runs it in a non-interactive shell again. If you want to use bash from the command line, then do it like this:

$ bash -i test.sh

Upvotes: 9

user332325
user332325

Reputation:

This variable is somehow treated in a special way in bash (but eg in AIX or HPUX sh that i know you can access it even while non-interactive). It's being used only in interactive shell, so there's no possibility to get access to its value in non-interactive invocation.

Sorry, it's no answer, but that's how it is...

Upvotes: 2

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