To all geeks,

What I want to achieve:
1. Accept two filenames from user and store the filenames in two variables (FILE1 and FILE2)
2. Check if files exisits. If doesn't, then exit
3. If files exist, look for a particular string in both files
4. If the string exists, then change the filenames (FILE1 and FILE2) to the string that was looked up in the #3
5. If string does not exist, then do nothing
6. Build up another filename (FILE3) which is some combination of FILE1 and FILE2

Here's the code that I have written. Everything else works fine EXCEPT for point # 4. The variable substitution just doesn't work. I've tried many modifications, and this is the last one which still doesn't work.

Code:

#!/bin/bash

echo "Enter first filename:"
read FILE1
echo "Enter second filename:"
read FILE2

HOSTN="`grep "system hostname" $FILE1 | awk '{print $3}'`"
echo $HOSTN

if [[ -z "$HOSTN" ]]
  then
    :
  else
    FILE1=$HOSTN
    echo "$FILE1 , $HOSTN "
fi
HOST="`grep "system hostname" $FILE2 | awk '{print $3}'`"
echo $HOST
if [ -n "$HOST" ]
  then
   FILE2=$(grep "system hostname" $FILE2 | awk '{print $3}')
   echo "$FILE2 , $HOST "
fi

echo "Output follows..."


FILE3="${FILE1%%.*}""_""${FILE2%%.*}"
echo "$FILE1, $FILE2, "${FILE1%%.*}", "${FILE2%%.*}", $FILE3"

The outputs:

1. When the string exists in the file:

Code:

deepak@ubuntu:~/Desktop/VF-NL$ ./test.sh 
Enter first filename:
sample.cfg
Enter second filename:
sample1.cfg
IAGG03LDV
 , IAGG03LDV
IAGG03FTC
 , IAGG03FTC
Output follows...
_IAGG03FTCV

2. When the string does not exist in the file:
deepak@ubuntu:~/Desktop/VF-NL$ ./test.sh 
Enter first filename:
RM_CGA_apns.txt
Enter second filename:
UT_CGA_apns.txt


Output follows...
RM_CGA_apns.txt, UT_CGA_apns.txt, RM_CGA_apns, UT_CGA_apns, RM_CGA_apns_UT_CGA_apns
deepak@ubuntu:~/Desktop/VF-NL$

Like I said, I have tried many combinations, but nothing seems to be working right. THe variable substitution works well when I do it outside the if loop. but within the if loop, it just doesn't work.

OS:
deepak@ubuntu:~/Desktop/VF-NL$ uname -a
Linux ubuntu 2.6.38-11-generic #50-Ubuntu SMP Mon Sep 12 21:18:14 UTC 2011 i686 i686 i386 GNU/Linux
deepak@ubuntu:~/Desktop/VF-NL$

---------- Post updated at 08:41 PM ---------- Previous update was at 08:37 PM ----------

Been breaking my head since yesterday on what is going wrong with a simple substitution, but unfortunately can't seem to get it. Help from you geeks will be greatly appreciated.

Regards,
Deepak

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