UNIX for Dummies Questions & Answers

ahhh thanks for that spot.

Could I use the same general idea to do the same but have the user input an age and check against characters?

For that you can leave out the exclamation mark.

Code:

"${NAME//[0-9]}"

That's great thanks so much.


if [ "$NAME" = "" ] || [ "${NAME//[!0-9]}" != "" ];
just so I understand what's going on here -

I'm going to guess that // indicate "contain" and [!0-9] means can't contain a number?

// means replace every instance and [!0-9] means any character but a digit.
So, if $NAME with every non-digit removed is not empty.

ahhh i get it. Thanks so much for that. This whole learning a new language thing is pretty tough.

Can you have a look at this and let me know what's wrong?
This is my last step for this script.

Code:

if [ "grep -i "$NAME" details.txt" ];
then
echo "User already inputted."

else
echo "$NAME" >> details.txt
echo "$AGE" >> details.txt
echo "$NUM" >> details.txt

fi

What's happening is that it's just looping the entire script even if it is a new $NAME input.

Just found the test command - would this be something I would use to accomplish this?

Hi, something like this should work

Code:

if grep -qi "$NAME" details.txt
then
  echo "User already present."
else
  echo "$NAME" >> details.txt
  echo "$AGE" >> details.txt
  echo "$NUM" >> details.txt
fi

Here the return code of the grep command gets used for the if then else evaluation.

that got it.

your help has been much appreciated. I'm hoping I can get this stuff down so that I'll be able to re-pay the help down the road to people.