[SOLVED] zero-padding and sorting - Linux Shell Scripting

zero-padding and sorting - Linux Shell Scripting

I am trying to do some text file manipulation in Linux.

I have a file, called names.txt that looks like this:

A1
X12
B4
Y5
C10
Z23
B8
C3
Z6

And I need it to look like this:

A01
B04
B08
C03
C10
X12
Y05
Z06
Z23

GOAL: I need to zero-pad the single digits and then alphabetize the results, and save to file sorted_names.txt

I'm thinking I need to count the number of characters per line first, and if the number of characters is less than 2, then add a zero. Lastly I would need to sort alphabetically.

For starters, I think I do this to count the number of characters per line:

cat names.txt | while read line
do

  count=$(echo $line | wc -c)
  echo $line $count

done

Then my thought was to loop through count:

for COUNT in $count
if [( $COUNT = "3" )];
then
    echo doZeroPadHere
fi

Solution

Is it important to you to do it using only built-in Bash features? Because it seems easier to use sed and sort:

<names.txt sed 's/^\([A-Z]\)\([0-9]\)$/\10\2/' | sort >sorted_names.txt