Arch Linux

oliver

Member

Registered: 2007-12-12

Posts: 448

modifying /etc/passwd to run a script (with logging)

This is not Arch related so feel free to ignore...

The goal is to modify a users /etc/passwd entry so it runs a script instead of a shell.

As a proof of concept, this works:

#!/bin/bash

read -p "Enter your selection: " selection
case "$selection" in
  1) /usr/bin/ssh user@192.168.32.20;;
  *) exit 0;;
esac

If I su to a user with that as their "shell" I see the prompt, I can press 1 and login to the remote box

Then I thought I'd try to add some logging and script became this:

#!/bin/bash

read -p "Enter your selection: " selection
case "$selection" in
  1) /usr/bin/script -c "/usr/bin/ssh user@192.168.32.20";;
  *) exit 0;;
esac

This does work when run directly at the command line but does not work when set as a users shell in /etc/passwd... it's like it executes the script over and over again.  The output is:

Enter your selection: 1
Script started, file is typescript
Enter your selection: 1
Script started, file is typescript

So adding the /usr/bin/script to the mix is causing a problem.

What is the cause?  I'm assuming it's something to do with subshells but I thought the '-c' would resolve that.

How can I make it do as expected (without modifying .profile if possible.)  The end-goal is for users to log in and be presented with a list of servers to connect to

Is there a better way to accomplish this?

Last edited by oliver (2015-01-20 16:38:11)

nomorewindows

Member

Registered: 2010-04-03

Posts: 3,409

Re: modifying /etc/passwd to run a script (with logging)

You might just try bash instead of script, but then again it could probably be done somehow with bashrc.  Usually something like this, you use sh.

Last edited by nomorewindows (2015-01-20 16:40:24)

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oliver

Member

Registered: 2007-12-12

Posts: 448

Re: modifying /etc/passwd to run a script (with logging)

I'm trying to avoid modifying profiles due to the archaic way we handle user accounts at work... it would be one more thing to maintain but it's certainly not impossible.

I think I will switch to /bin/sh anyway - just used bash out of habit

And reading the first post back, I'm not sure it's entirely clear... but it works at the command line and only fails when it's set as a user's shell.  I'm not sure what the difference is

Last edited by oliver (2015-01-20 16:51:48)