bash - How to count number of words from String using shell

Question

I want to count number of words from a String using Shell.

Suppose the String is:

input="Count from this String"

Here the delimiter is space ' ' and expected output is 4. There can also be trailing space characters in the input string like "Count from this String ".

If there are trailing space in the String, it should produce the same output, that is 4. How can I do this?

Answer 1

echo "$input" | wc -w

Use wc -w to count the number of words.

Or as per dogbane's suggestion, the echo can be got rid of as well:

wc -w <<< "$input"

If <<< is not supported by your shell you can try this variant:

wc -w << END_OF_INPUT
$input
END_OF_INPUT