Poor mans apache bench

cb.sh

#! /bin/bash
#
# CurlBench. Dont want to install apache bench?
#
# Runs "curl" concurrently using arguments.
#
# Example: Make 100 requests to some domain (concurrency = 10)
# $ curl.sh http://some.domain.com 100 10
#
set -B 
url=${1:-http://some.domain.com}
count=${2:-1}
concurrency=${3:-1}
iterations=$((count/concurrency))
for i in $(seq 1 $iterations); do
  echo '';
  echo "$i ------------------------";
  echo "GET $url"
  echo '';
  seq 1 $concurrency | xargs -I $ -n1 -P$concurrency curl -D - "$url";
  echo '';
done