How do I count the number of occurrences of a string in an entire file?

Question

Is there an inbuilt command to do this or has anyone had any luck with a script that does it?

I am looking to count the number of times a certain string (not word) a

Answer 1

You can use basic grep command:

Example: If you want to find the no of occurrence of "hello" word in a file

grep -c "hello" filename

If you want to find the no of occurrence of a pattern then

grep -c -P "Your Pattern"

Pattern example : hell.w, \d+ etc