UNIX for Advanced & Expert Users

Ok, I'm trying to understand something. I've done some searches, but couldn't find anything definitive.
Now, I have come across a few things around the web cautioning against "eval", so that's duly noted, and any advice to alternative methods is greatly appreciated

So, easiest thing is probably a simple example:
I have the following 3 scripts setup:

Code:

::::::::::::::
func.lib
::::::::::::::
## my functions

function f_echo {
   echo `date +%Y%m%d_%H%M%S`": $*"
}

::::::::::::::
main.ksh
::::::::::::::
#!/bin/ksh

v_RUN_JOB=$1

# setup functions
. ./func.lib

# prove it works
f_echo  hello world

eval ${v_RUN_JOB}

::::::::::::::
test.ksh
::::::::::::::
#!/bin/ksh

# does this work??
f_echo  quick brown fox

a quick chmod to make sure they are executable ...

Code:

chmod +x main.ksh
chmod +x test.ksh

Then I call main:

Code:

./main.ksh  ./test.ksh

Output is:

Code:

20140312_131301: hello world
./test.ksh[4]: f_echo:  not found

So, main can see the function, however, the called script cannot?
Can anyone suggest a way to do this?

In case it's not obvious, I am passing a script to another (wrapper) script (ie think framework).
So the "main" script will handle some common setup/logs/etc., then run the passed script.
This isn't designed for interactive users, it's for a backend batch framework.

Should I be using the "eval" in this manner? or is there another command/option to ensure the functions can be handled?
So far, variables have worked just fine, but I only hit this with the function declarations.

Thanks!

(I'm on Sun Unix 5.10, however, any (mostly?) generic method of doing this would be appreciated)

Your first shell script is defining a function and after that it knows about that function. But other shell scripts do not. Each shell script must define its own functions.

I was wondering about that.

so need to add:

Code:

. ./func.lib

to each script?
I can live with that

I was just hoping there was a "better" way ...

You could source the second script with the . command. Then the 2nd script runs in the first process. However the second script is really just some commands (like your .profile file is). It is not really a script.

Oh that's a thought - hadn't even thought about doing that.

However, as you say, "it's not really a script" ... so if that second script IS intended as a full script - that's not a good way of doing that, though, is it?

I believe that a script should stand on its own two feet. It should not require helper script to preset an environment for it. If it needs functions, it should seek them out and install them. It should set the PATH variable if it needs anything special. And the same with any other environment variable. We get a a lot of threads about a script that works from the command line but fails as a cron job. That never happens with a first class script.

Yeah, I understand. I've hit that in previous places I worked. So with this, that's kind of what I'm trying to avoid Trying to make sure everything's set up front.
Function list wasn't a must have, so I'll handle it more traditional.

Thanks for the advice!