Shell Programming and Scripting

==
A big apology for the completely generic thread title!!
==

Hi All,

Just wondering if somebody could please give me a hand with a script I'm writing. At the moment it's doing what I want it to do but I there are a couple of things that I would like to add to it and I also feel that it's probably not written quite as well as it could be. I've had a little bit of help and have thrown the rest together (as you can probably tell)

=====
read -p "Enter Filename: " filename;
if [ "$filename" = "" ]
then
echo "You must enter a Filename!"
exit 1
fi
read -p "Enter File System: " filesystem;
if [ "$filesystem" = "" ]
then
echo "You must enter a file system!"
exit 1
else
grep $filename /dir/tmp/filename.xtn | grep $filesystem | awk '{print$18}' | command &
=====

The command after the else is working fine (have changed a couple of things in there just for the sake of this post)

There are two changes that I'd like to make but I'm not having too much luck finding an answer:

1. I'd like to make it mandatory that the Filename MUST contain at least 6 characters (letters and/or numbers) before proceeding to the next step.

2. I'd like the script to prompt the user if they would like to perform this operation on another file with a Yes/No answer at the end.

Nice to do if possible:

1. Force Caps on the Filename variable.

Many thanks, Ben

Sorry for the delay. Don't know why your post missed our attention.

1. Six letters or more:

Code:

if echo $filename | sed -e '/....../' ; then
  # filename is ok
else
  print "Filename must be 6 or more characters in length!"
fi

Using a similar technique you can check for other things, such as spaces, invalid characters, etc.

3. Convert to upper case:

Code:

filename=`echo $filename | tr 'a-z' 'A-Z'`

Note: someone please check me on this: I've not used tr in a long time.

Finally, #2:

Code:

let done=0
while [ $done == 0 ]; do 
  # YOUR CODE ABOVE

  read -p "Are you done yet? (Y/N) " yesno
  if [ "$yesno" == "Y" -o "$yesno" == "y" ]; then
     let done=1
  fi
done

There's no need for an external command:

Code:

if [ ${#filename} < 6 ]; then

Non-standard. All you need is:

Code:

done=0

Non-standard. Use '=' not '=='.

The -p option is non standard.