Printing array elements without white space using printf

Question

I can print my array elemets using echo in a loop, but the output format is really bad . there I tried injecting tab but there is just a lot of spaces between the elements ssince each element length is different. I have no idea how to use printf ? I tried , but it just not working properly. is there a way to format my printf or echo so I have equal number of spaces between each element? This is driving me mad.

while [[ $counter -lt $nai ]];
do
#echo ${slist[$counter]} $'\t' ${sstate[$counter]} $'\t' $'\t' ${scached[$counter]}
printf ${slist[$counter]} $'\t' ${sstate[$counter]} $'\t' $'\t' ${scached[$counter]}
counter=$(( $counter + 1 ))
done

IN short I just want to print my elements in a format with equal number of spaces between the elements like this

  abc  cdf  efg

What i'm getting is

  abc       cdf            efg

Thanks

Answer 1

If you want to print elements with N spaces between them, you can use printf:

a="foo"
b="somestring"
c="bar"

# Print each argument with three spaces between them
printf "%s   " "$a" "$b" "$c"
# Print a line feed afterwards
printf "\n"

This results in:

foo   somestring   bar
otherdata   foo   bar

You can also use the format %-12s to pad each element to 12 character:

# Pad each field to 12 characters
printf "%-12s" "$a" "$b" "$c"
printf "\n"

Resulting in:

foo         somestring  bar         
otherdata   foo         bar

Answer 2

Try using a format string with printf

printf "%s  %s  %s\n" ${slist[$counter]} ${sstate[$counter]} ${scached[$counter]}

If the fields don't have whitespace, use column -t:

{
echo my dog has fleas
echo some random words here
} | column -t

my    dog     has    fleas
some  random  words  here

Or, in your case: while ...; do ...; done | column -t