ACK vs. GREP

Setup

I used my Macbook Pro for these benchmarks.

• Processor: 2.33GHz Intel Core 2 Duo
• Memory: 3GB
• HD: 160GB 5400 RPM

There are three tests, I ran: searching a particular file, searching throught a piped input, and searching through a rails project with many subdirectories to find a particular word.

I generated a log with 100000 lines of random text using irb:


pids=['12345','54321','55555','65432','88888']
chars='abcdefghjkmnpqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ123456789 '
File.open('blog_log.txt', 'w') do |f|
100000.times {f.write("#{Time.now.to_s} rails[#{pids[rand(pids.size)]}] "); 500.times{f.write("#{chars[rand(chars.size)].chr}")}; f.write("\n") }
end


Then, I ran sed, awk, grep, and ack on the log file searching for ‘rails[12345]‘. I also did tail the log and piped it to those tools, because sometimes I might want the tail end of a log.

I also had a project with about 29900 files. I ran grep and ack on it to find any references to ‘app_helper’ in my files.

I ran each command 3 times with time command and averaged the real times, while outputting to /dev/null to not have any output.

Results

Test 1
Commands:

time grep 'rails\[12345\]' blog_log.txt > /dev/null
time awk '/rails\[12345\]/' blog_log.txt > /dev/null
time ack 'rails\[12345\]' blog_log.txt > /dev/null
time sed -n "/rails\[12345\]/ p" blog_log.txt > /dev/null


Test 2
Commands:

time tail -n 50000 blog_log.txt | grep 'rails\[12345\]' > /dev/null
time tail -n 50000 blog_log.txt | awk '/rails\[12345\]/' > /dev/null
time tail -n 50000 blog_log.txt | ack 'rails\[12345\]' > /dev/null
time tail -n 50000 blog_log.txt | sed -n "/rails\[12345\]/ p" > /dev/null


Test 3
Commands:


time grep -r app_helper . > /dev/null
time ack app_helper > /dev/null