krb command not working in ksh script

Question

On a RedHat 7, when I run the following command to get a Kerberos ticket:

krb my_user

It sends back :

Ticket for 'my_user' is valid until 08:36 (28/01)

Now I need to run this command from a script. Without changing directory, I create a ksh script with the following content:

#!/bin/ksh
krb my_user

When I execute the script, I have the following error:

./script.ksh[2]: krb: not found [No such file or directory]

I don't understand where this krb command is found when I execute it directly from command line.

The krb command is not in the aliases when I list them.

If I run a locate krb it doesn't return anything just called krb.

If I run which krb it says

/usr/bin/which: no krb in (/usr/java/default/bin:/bin:/usr/bin:/usr/local/bin:/bin)

What should I do to make this krb command work from my script?

What’s the result of type krb? Odds are it’s an alias or a function. — bxm
– bxm, Commented Jan 27, 2020 at 23:41
type krb returns krb is a function krb () { .... So this is a function. Now I have to find out what a function is in Linux context. Thx @bxm. — Nanorex
– Nanorex, Commented Jan 28, 2020 at 9:01

bxm · Accepted Answer · 2020-01-29 08:58:42Z

0

A shell function that is available at the shell prompt is not automatically available to a script called from that shell.

There are two high level ways to get access.

Source the script that sets up the function. Before you do this you would want to have a really good idea of what else this script is doing; without some local knowledge I can't recommend this as a safe option.
Export the function.

In simplest terms, you could achieve the latter option like so:

$ export -f krb
$ yourscript.sh

You would be better off adding the export command to your shell profile, such that it will be executed at login.

answered Jan 28, 2020 at 11:44

bxm

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