sed/awk | single digits to two digits (zero) after a second slash

Question

maybe someone can help me briefly... for example in file.txt...

nw-3001-e0z-4581a/2/5
sed 's/\<[0-9]\>/0&/' file.txt ...
nw-3001-e0z-4581a/02/5

but I want the filled zero only after the second slash, the first number should remain a single digit

thanks in advance! greetz

Answer 1

Could you please try following, written and tested with shown samples. Simply setting field separator and output field separator as / for awk program and then simply adding 0 before 3rd column(if there is only single digit present in it) and print the line.

echo "nw-3001-e0z-4581a/2/5" | awk 'BEGIN{FS=OFS="/"} {$3=sprintf("%02d",$3)} 1'

Answer 2

You can use

awk 'BEGIN{FS=OFS="/"} $NF ~ /^[0-9]$/ {$NF="0"$NF}1' file.txt

Details :

• BEGIN{FS=OFS="/"} - sets input/output field separator to /
• $NF ~ /^[0-9]$/ - if last field is a single digit
• {$NF="0"$NF} - prepend last field with 0
• 1 - print tjhe result.

Answer 3

Using sed:

sed -rn 's@(^.*/)(.*/)([[:digit:]]{1}$)@\1\20\3@p' <<< "nw-3001-e0z-4581a/2/5"

Split the string into 3 sections using regular expressions (-r). Ensure that the last section has one digit only with [[:digit:]]{1} and substitute the line for the first and second sections, followed by "0" and the third section, printing the result.

Answer 4

$ sed 's:/:&0:2' file
nw-3001-e0z-4581a/2/05

If that's not all you need then edit your question to show more truly representative sample input/output including cases that doesn't work for.