grep Word Count Command

How do I count words using grep command under Linux / Unix like operating systems?

You can pass the -c option to grep command to suppress normal output and display a count of matching lines for each input file. The syntax is follows:
grep -c "string" file
In this example, search for a word called ‘var’ and display a count of matching lines:

grep -c 'var' /etc/passwd

You can pass the -v option to count non-matching lines:

grep -v 'var' /etc/passwd
However, this will not count words. To count exact matched words, enter:

grep -o -w 'word' /path/to/file/ | wc -w
The grep -o command will only display matched words and the wc -c command will display the word counts.