How to use linux commands to count the frequency of occurrence of a word in a text

How to use linux commands to count the frequency of occurrence of a word in a text

Use this command to find out that words in the text appear frequently in descending order.

Cat words.txt | tr-cs "[a-z] [A-Z]" [\ 012 *] "| tr A-Z a-z | sort | uniq-c | sort-k1nr- k2 | head-10

But sometimes we want to find out the frequency of a word, then we can use the following commands
File Name: file search word name: word
Operation Command:
(1) more file | grep-o word | wc-l


(2) cat file | grep-o word | wc-l


(3) grep-o test word | wc-l
If the requirements still cannot be met, you can only write a linux script for implementation. You can use awk.