Replicate a string names x times and ascribe replication number - awk

Question

I would like to replicate key names x number of times and have a separate column to indicate the replication number, e.g. let's say I have three key names as follows:
101
102
103
So, I would like each of the above numbers (names) replicated 3 times and to have a separate identifier number equal to 4 characters. It would therefore look like this:
101 0001
101 0002
101 0003
102 0001
102 0002
102 0003
103 0001
103 0002
103 0003
I guess this could be genered with a relatively straight forward awk script? *Edit: I would like to not specify the names to replicate in the script - it should be "replicate all names in this text file", as there are a lot of them (~400) and all with variable name types.
Thank you in advance!

Answer 1

In bash
echo {101,102,103}" "{01,02,03}
101 01 101 02 101 03 102 01 102 02 102 03 103 01 103 02 103 03
Following Fedorqui's advice for newlines
printf "%s\n" {101,102,103}" "{01,02,03}
101 01
101 02
101 03
102 01
102 02
102 03
103 01
103 02
103 03

Answer 2

Using the awk -v flag to pass a variable number which is the number of repeats for each line, and sprint to format the number into 2 decimal places with zero padding:
awk -v number_repeats=3 '{
for(i=0; i<number_repeats; i++) {
print $0, sprintf("%02d", i+1)
}
}'

Answer 3

If you don't mind GNU Parallel
parallel -k 'printf "%02d %02d\n"' ::: {6..12} ::: 1 2 3
06 01
06 02
06 03
07 01
07 02
07 03
08 01
08 02
08 03
09 01
09 02
09 03
10 01
10 02
10 03
11 01
11 02
11 03
12 01
12 02
12 03
Or, if your keys are in a file, called keys like this
32
45
78
You can read the file
parallel -k 'printf "%02d %02d\n" {1} {2}' :::: keys ::: 1 2 3
32 01
32 02
32 03
45 01
45 02
45 03
78 01
78 02
78 03