awk padding column

Shell Programming and Scripting
1

Hello, i am trying to pad a column

A1
A2
A10
B2
B8
B12

to look like

A01
A02
A10
B02
B08
B12

using awk

 awk '{sprintf ("%c" $1 "%03d",int (0))}' file.txt

getting
awk: (FILENAME=file.txt FNR=1) fatal: not enough arguments to satisfy format string

2 
nawk '$1=sprintf("%s%02d",substr($1,1,1),substr($1,2))' file.txt
3

nawk is not an option for me :frowning:

4 
$ echo A1 | awk '{printf ("%1c%02d",substr($1,1,1),substr($1,2,2))}'
A01

$ echo A12 | awk '{printf ("%1c%02d",substr($1,1,1),substr($1,2,2))}'
A12
5

is 'awk' an option then?

6

Yes the awk method worked. Thank you very much.
I am getting more in depth with awk at my job, any good study guides to suggest. currently only finding targeted related scenarios in my searches.

7

See

I have a couple of these books on a shelf behind my desk, for handy reference.