Bash - simple URL ping tool (URL response time measuring)

In this short article, we would like to show how in Bash, write a simple tool that pings indicated URLs checking response time.

test_requests.sh file:

#!/bin/bash

function test_request()
{
        url="$1"

        t1=$(date +%s%9N)

        curl -k "${url}" &> /dev/null

        t2=$(date +%s%9N)
        dt=$((t2 - t1))

        printf "%16d  %16d  %16d  %16d     %s\n" \
                $dt \
                $(($dt / 1000)) \
                $(($dt / 1000000)) \
                $(($dt / 1000000000)) \
                "$url";
}

echo
echo -n " [in nanoseconds] ";
echo -n "[in microseconds] ";
echo -n "[in milliseconds] ";
echo -n "     [in seconds] ";
echo -n "  [requested url] ";
echo

test_request "https://dirask.com/posts/MySQL-select-last-row-j890a1"
test_request "http://localhost/posts/MySQL-select-last-row-j890a1"

echo

Script running:

./test_requests.sh

# or:

watch -n 1 ./test_requests.sh

Example output:

Every 1.0s: ./test_requests.sh                                                                                                                                                                                                                                                                                                                                                                                     my-server: Sun May 23 13:00:56 2021


 [in nanoseconds] [in microseconds] [in milliseconds]      [in seconds]   [requested url]
       110754854            110754               110                 0     https://dirask.com/posts/MySQL-select-last-row-j890a1
        95801101             95801                95                 0     http://localhost/posts/MySQL-select-last-row-j890a1

Custom Host: header example

In this example, we are able to change Host: header to the proper domain.

That configuration is useful when we have VirtualHosts that redirect traffic depending on a specific domain. 

test_requests.sh file:

#!/bin/bash

function test_request()
{
        url="$1"
        host="$2"

        t1=$(date +%s%9N)

        if [ -n "$host"  ];
        then
                curl -k --header "Host: $host" "$url" &> /dev/null
        else
                curl -k "$url" &> /dev/null
        fi

        t2=$(date +%s%9N)
        dt=$((t2 - t1))

        printf "%16d  %16d  %16d  %16d     %s" \
                $dt \
                $(($dt / 1000)) \
                $(($dt / 1000000)) \
                $(($dt / 1000000000)) \
                "$url";

        [ -n "$host" ] && echo -n "  (Host: $host)";

        echo
}

echo
echo -n " [in nanoseconds] ";
echo -n "[in microseconds] ";
echo -n "[in milliseconds] ";
echo -n "     [in seconds] ";
echo -n "  [requested url] ";
echo

test_request "https://dirask.com/posts/MySQL-select-last-row-j890a1" ""
test_request "https://localhost/posts/MySQL-select-last-row-j890a1" "dirask.com"

echo

Script running:

./test_requests.sh

# or:

watch -n 1 ./test_requests.sh

Example output:

Every 1.0s: ./test_requests.sh                                                                                                                                                                                                                                                                                                                                                                                     my-server: Sun May 23 13:00:56 2021


 [in nanoseconds] [in microseconds] [in milliseconds]      [in seconds]   [requested url]
       110754854            110754               110                 0     https://dirask.com/posts/MySQL-select-last-row-j890a1
        95801101             95801                95                 0     https://localhost/posts/MySQL-select-last-row-j890a1  (Host: dirask.com)