Benchmarking various ways to grep recursively

grep_bench.rb

require 'benchmark'

Benchmark.bm(15) do |test|
    test.report('grep-recursive') do
        system('grep -r --include="*.h" -l include /usr/src/linux-headers-2.6.32-30/ > /dev/null')
    end

    test.report('grep-find') do
        system('grep -l include $(find /usr/src/linux-headers-2.6.32-30/ -name "*.h" -print) > /dev/null')
    end

    test.report('find-xargs-grep') do
        system('find /usr/src/linux-headers-2.6.32-30/ -name "*.h" -print0 | xargs -0 grep -l include > /dev/null')
    end

    test.report('ruby-oneliner') do
        system('ruby -e "Dir[\'/usr/src/linux-headers-2.6.32-30/**/*.h\'].each { |f| puts f unless open(f).grep(/include/).empty? }" > /dev/null')
    end

    test.report('find-exec-grep') do
        system('find /usr/src/linux-headers-2.6.32-30/ -name "*.h" -exec grep -l include "{}" \; > /dev/null')
    end
end

# Results
# 
# $ ruby grep_bench.rb 
#                      user     system      total        real
# grep-recursive   0.000000   0.000000   0.140000 (  0.126757)
# grep-find        0.000000   0.000000   0.140000 (  0.120633)
# find-xargs-grep  0.000000   0.000000   0.200000 (  0.119407)
# ruby-oneliner    0.000000   0.000000   0.920000 (  0.906290)
# find-exec-grep   0.000000   0.000000  78.840000 ( 22.173068)