Save output of bash command for use with pipe command (|)

Question

Say I have the following problem

• Count the files in the folder which have an "a" in the filename
• Repeat for "e", "i" and all the other vowels

One solution is:

FilesWithA=$(ls | grep a | wc -l)
FilesWithE=$(ls | grep e | wc -l)
FilesWithI=$(ls | grep i | wc -l)
FilesWithO=$(ls | grep o | wc -l)
FilesWithU=$(ls | grep u | wc -l)

This works fine, but the folder contains many thousands of files. I'm looking to speed this up by capturing the output of ls in a variable, then sending the output to grep and wc , but the syntax is defeating me.

lsCaptured=$(ls)
FilesWithA=$($lsCaptured | grep a | wc -l) #not working!

Answer 1

Use this :

#!/bin/bash

captured="$(printf '%s\n' *)"
filesWithA=$(grep -c a <<< "$captured")

Notes :

• <<< is a here-string
• please, thanks to not parsing ls output