UNIX for Dummies Questions & Answers

printf and echo are not substitutes for each other, they work very different ways. echo just prints what you give it, printf can format it in various ways.

If you want to print several newlines, printf is a good bet. You don't get echo -e everywhere, but printf works nearly the same way wherever you go.

If you want to print a string without a newline, printf can do that everywhere too. printf "%s" "mystring"

If you want to format numbers, printf can also do that for you.

Code:

printf "%.3f\n" 10
10.000

In fact it can do quite a few things, more than I have time to mention here. See man printf for details.

okay thank you, if it is not too much to ask may i know how to check if array is empty or not. Is the below approach is correct?

Code:

IF [ ${#ARR[*]} -gt 0 ] 
then
  printf "%s" "Array is not empty"
else
  printf "%s" "Array is empty"
FI

That looks correct.

Is there a way where I can combine the floating point number scale along with the string formatting, something like below

Code:

printf "%.3f %s\n" Difference is 10

Difference is 10.000

Yes, the format string uses one 'thing' per item. So:

Code:

printf "%s %.3f\n", "Difference is" "10"