Use of exported variable

Shell Programming and Scripting
1

i have to use the exported variable from one script into another script

ex :
A.ksh

      
            # !/bin/ksh
               chk1=56
               export chk1
 

B.ksh

    
              # !/bin/ksh
               echo $chk1

i have executed the A.ksh then B.ksh but nothing is displayed.
could some one tell the correct procedure to do this export?

thanks

2

source A.ksh inside B.ksh:-

# !/bin/ksh
. ./A.ksh
echo $chk1
3

the target is to use the variable of A.ksh into B.ksh .
because the same variable can be used differently in both the script and
in real time both the script will run pararlly and one script can not call other.

4

Variables defined in a script belong to that script, so when you start a new script it uses a new set of variables. So I don't think if there are any other option other than sourcing. But please don't consider my opinion as final, somebody else in this forum will have a solution.

5

Write variable to file, then read it in other script.

6 
an12:/home/vbe $ echo $VAL   # VAL not set yet...

an12:/home/vbe $ echo $$
14811192                              #Begin SHELL PID
an12:/home/vbe $ ksh             # New SHELL
an12:/home/vbe $ echo $$
22544394                               # New SHELL PID
an12:/home/vbe $ export VAL=2:echo      # Variable VAL set now...
an12:/home/vbe $ echo $VAL
2:echo
an12:/home/vbe $ ksh             # Second New SHELL
an12:/home/vbe $ echo $$
21561462                                       # See PID is different...
an12:/home/vbe $ echo $VAL
2:echo                                   # And yes the variable was exported, so it this here...
an12:/home/vbe $ echo $$
21561462
an12:/home/vbe $ exit
an12:/home/vbe $ echo $$
22544394
an12:/home/vbe $ echo $VAL
2:echo
an12:/home/vbe $ exit
an12:/home/vbe $ echo $VAL    # Back to begin SHELL where has no knowledge of this variable...

an12:/home/vbe $ echo $$
14811192
an12:/home/vbe $
7

There is no need to export a variable if one is only sourcing the other file. Variables are exported so that they work if one script calls another script in a subshell:

A.ksh:

#!/bin/ksh
chk1=56
export chk1
./B.ksh

$ ./A.ksh
56

If the scripts are to be run in parallel then you could use a third script, export the variable there and run both scripts in parallel in the background..
Or you can have a third file, set the variables there, and source the file in either script. You only need to export those variables if those scripts in turn call other scripts in a subshell that need that variable...

--
As a side note. The shebang #! only works if there is no space between the two characters, otherwise it is just a comment.