How to identify the calling script?

Shell Programming and Scripting
1

Hi,

I have two scripts ( /tmp/k1.sh and /tmp/k2.sh ).
k1.sh calls the k2.sh .
For security reasons, I must be sure that the k2.sh is being called by the k1.sh .
Is it possible for the k2.sh identify that it's been called by the k1.sh?
I mean, identify the complete path of the k1.sh ( /tmp/k1.sh ).

Thanks for any help,

Cremm.

2

Interesting.

Couple of ways.

  1. Why dont you embed k2.sh in k1.sh ? After all k2 serves k1 alone.

  2. Just before you call k2.sh, export a unique variable from k1.sh. When you start k2.sh, check for that new export. If not there, then act accordingly.

  3. Use the features from ps. You can list the ps output in a tree format. From k2.sh get your own pid and your parents pid ($PPID), traverse up the list 1 step to get your parent's PID and CMD. Compare that CMD with the complete path of k1.sh or compare just the pid value. If it matches, proceed. This works well if the path to k1.sh remains the same throughout.

There may be other ways as well... nothing strikes me now.

But none of these solutions stand (except for sol1) if someone writes their own k1.sh.

3

Try the following

ps -ef | grep $PPID  | grep -v grep | grep -v awk | awk '{ print $7 }'
4

Vino,

I can't use the solutions 1 and 2 for security reasons, but the third solution sounds to be great.

I did this:

The code:

#!/bin/ksh
var1=`echo $$`
echo "k2.sh pid => " $var1 ## Just for checking. Will be erased...
echo "Listing processes with the k2.sh pid" ## Just for checking. Will be erased...
ps -ef | grep $var1 ## Just for checking. Will be erased...
v=`ps -ef | grep $var1 | sort +1 -2 | cut -d" " -f4 | head -1`
echo "k2.sh parent process => "$v ## Just for checking. Will be erased...
echo "Listing processes with the k2.sh parent process" ## Just for checking. Will be erased...
ps -ef | grep $v ## Just for checking. Will be erased...
echo "The parent process..." ## Just for checking. Will be erased...
ps -ef | grep $v | sort | head -1 | cut -d" " -f13

The result:

server01:/var/tmp$ /var/tmp/k1.sh
k2.sh pid => 29483
Listing processes with the k2.sh pid
user01 29484 29483 1 12:43:59 pts/38 0:00 ps -ef
user01 29483 29482 0 12:43:59 pts/38 0:00 /bin/ksh /var/tmp/k2.sh
k2.sh parent process => 29482
Listing processes with the k2.sh parent process
user01 29482 28411 0 12:43:59 pts/38 0:00 /bin/ksh /var/tmp/k1.sh
user01 29483 29482 0 12:43:59 pts/38 0:00 /bin/ksh /var/tmp/k2.sh
The parent process...
/var/tmp/k1.sh

Can you see any security hole in it?

Thanks a lot for your help!!

Cremm.

5

fpmurphy,

your solution didn't work for me. Check it out.....

server01:/var/tmp$ /var/tmp/k1.sh
pts/27
0:00
0:00
pts/101
?
?
?
pts/15
pts/15
pts/27

Thanks anyway for your help,

Cremm.

6

Making it simpler, after reading Vino's answer slowly....

v=$PPID
ps -ef | grep $v | sort | head -1 | cut -d" " -f14

[]s,

Cremm.

7

Making it....

ps -ef | grep $PPID | sort | head -1 | awk '{ print $NF }'

server01:/var/tmp$ /var/tmp/k1.sh
/var/tmp/k1.sh

s,

Cremm.