because osx doesn’t have one.

[visnup@Octal ~]$ cat /usr/local/bin/pgrep 
#!/usr/bin/env ruby

list = `ps -Ao pid,command`.split "\n"
matches = list.select do |l|
  pid, command = l.split nil, 2
  command.downcase.include? ARGV.first.downcase and pid.to_i != Process.pid
end

puts matches