[cgjoker]

How would I go about switching user ids in a script.

Reason for this would be that I have one process that is using one particular id, (say id1), and I would like it to run a script which would switch all following scripts to be run under another id, (say id2).

So, id1 runs a script which would switch to id2 so that all concurrent scripts run under id2.

Any ideas?

I thought this would do it but not quite.

#!/bin/ksh
echo "hello"
pwd
login id1
password1
pwd
touch newfile.dat
exit;

[Squashman]

Hmm, You would have to use the SU command to switch users but I am not sure if you can script the password.

[tsunam]

at least not in a bash shell type script. In others you might be able to but still be tough.

[codejockey]

Hmm, You would have to use the SU command to switch users but I am not sure if you can script the password.

The Squashman has the right idea. The su command (used to become a different user) requires that when you invoke it, you are running from a terminal. Attempting to use a construct such as: echo password | su root will not work, because the su command checks to see if input is coming from a terminal (and input coming from a pipe does not qualify).

You don't say why you have two different IDs involved here (apparently, one ID updates a file used by another ID); the problem might be solved simply by changing the file permissions.

Hope this helps.

[cgjoker]

The idea is that we'd have an external production id which would initially launch a script for us, but we'd want to switch the script process flow to our own production id.

From the sounds of your guys comments, it doesn't sound like it can be done. Ill keep looking into this though.

Thanks.

[Squashman]

I think your only option is to use SUDO and setup the sudo config file to not require a password.

[codejockey]

I believe you could also do this fairly simply in a C program (which also makes me suspect that perl would support this as well).

Hope this helps.

[cgjoker]

I was thinking of trying something like...

su - user -c "/directory/myscript.sh"

[codejockey]

I suspect this would work if you were root when you started the script, since root can su to any ID without authentication (i.e., no prompt for password) -- but I haven't tested that suspicion, since I don't have access to my Linux system at the moment. However, if you were not root when you started the script, the su command will check to see if the process invoking it is associated with a terminal. Since you are running the script in background (most likely), you have dissociated yourself from a terminal (which is why cntl-C, cntl-pipe, etc. have no effect on background processes), and su will stop before you can complete the switch to another ID. Also, how were you expecting su to authenticate the attempt to switch to another user? Your code doesn't seem to provide the password for "user" anywhere ...

You definitely have the right idea, however. Unfortunately, you're running into some of the security inherent in Unix/Linux which is making things difficult.

Finally, I still wonder if some configuration tweaking wouldn't do the job for you. For example, the production ID starts your script and executes until it's time to change to the other id. Assuming permissions were set correctly, you could have the script source the .login (or similar) file for the second ID, thus re-setting the environment. The script could continue to execute without needing to do an su command at all. Is this what you have in mind?

Hope this helps -- additional info appreciated.