Shell Programming and Scripting

echo "In Main_shell_script.sh"
FILENAME="original.txt"         # LINE 1

DST_FILENAME=$FILENAME   # LINE 2
echo "FILENAME = {$FILENAME}"
echo "DST_FILENAME = {$DST_FILENAME}"

. /home/shell_script_A.sh      # Calling to execute in the same address space.

DST_FILENAME=$FILENAME   #LINE 3
echo "In Main_shell_script.sh"
echo "FILENAME = {$FILENAME}"        # prints blank
echo "DST_FILENAME = {$DST_FILENAME}"    # prints blank

echo "In shell_script_A.sh"

FILENAME=""                        # clearing the FILENAME
echo "FILENAME = {$FILENAME}

. /home/shell_script_B.sh

echo "In shell_script_B.sh"
FILENAME="sample.txt"        # reassigning the FILENAME
echo "FILENAME = {$FILENAME}"

In Main_shell_script.sh
FILENAME = {original.txt}
DST_FILENAME = {original.txt}

In shell_script_A.sh
FILENAME = {}

In shell_script_B.sh
FILENAME = {sample.txt}

In Main_shell_script.sh
FILENAME = {}
DST_FILENAME = {}

FILENAME=""                        # clearing the FILENAME
echo "FILENAME = {$FILENAME}"

[otto@centosgeek ~]$ ./Main_shell_script.sh
In Main_shell_script.sh
FILENAME = {original.txt}
DST_FILENAME = {original.txt}
In shell_script_A.sh
FILENAME = {}
In shell_script_B.sh
FILENAME = {sample.txt}
In Main_shell_script.sh
FILENAME = {sample.txt}
DST_FILENAME = {sample.txt}
[otto@centosgeek ~]$

#!/bin/bash
clear
echo "Starting execution of main script..."
i=1
while [ $i -le 5 ]
do
        echo $i
            (( i++ ))
            done
export i
echo "Execution of main script OK. Now calling script_a.sh..."
./script_a.sh $i

#!/bin/bash
echo "This is script_a.sh..."
echo $1

Starting execution of main script...
1
2
3
4
5
Execution of main script OK. Now calling script_a.sh...
This is script_a.sh...
6
gacanepa@debian:~/scripts/bash/tests$