UNIX for Dummies Questions & Answers

Hi,

If a script A(Parent) is running and script B(child) is run from script A, will the variables in script A be past to script B?
Will the variables exist only for the duration of running the script?

Thank you

When a process (in this case a script) is running, it runs with a certain environment. This environment is passed on to any children that the process may spawn. So any variables that are required to be available to the child process must be present in the parent process' environment.

You can make a variable part of a shell's environment using the export command in sh/ksh/bash or the setenv command in csh/tcsh.

Depends on the way you invoke the script B from A.

See this

Code:

[/tmp]$ cat a.sh
#! /bin/sh
a=10
export b=15
echo "Calling as ./b.sh"
./b.sh
echo "Calling as . ./b.sh"
. ./b.sh
[/tmp]$ cat b.sh
#! /bin/sh

echo "a=[$a]"
echo "b=[$b]"
[/tmp]$ ./a.sh 
Calling as ./b.sh
a=[]
b=[15]
Calling as . ./b.sh
a=[10]
b=[15]
[/tmp]$