#!/bin/bash

it=10

bench () {
    echo -n $1:
    time for ((i = 0; i < it; i++)); do
        "$@" /usr/include/{*.h,*/*.h} > /dev/null 2>&1 < /dev/null
    done
    echo
}

bench grep -h "#include.*stdio"
bench awk '/#include.*stdio/ {print}'
bench sed -rn '/#include.*stdio/p'
bench perl -ne 'print if /#include.*stdio/'