Bash Script to Ping Multiple Hosts with Output

Use a Bash script with a loop like for host in host1 host2; do ping -c 1 -W 1 $host && echo "$host is reachable" || echo "$host is unreachable"; done to ping multiple hosts and show their status.

Examples

Inputhosts="google.com github.com"

Outputgoogle.com is reachable github.com is reachable

Inputhosts="192.168.1.1 10.255.255.1"

Output192.168.1.1 is reachable 10.255.255.1 is unreachable

Inputhosts="localhost invalid.host"

Outputlocalhost is reachable invalid.host is unreachable

How to Think About It

To ping multiple hosts, list their names or IPs, then loop over each one. For each host, run the ping command once and check if it succeeds. Print a message saying if the host is reachable or not.

Algorithm

1

Get the list of hosts to ping

2

For each host in the list, do:

3

Run ping command once to check connectivity

4

If ping succeeds, print host is reachable

5

Otherwise, print host is unreachable

Code

bash

#!/bin/bash
hosts="google.com github.com invalid.host"

for host in $hosts; do
  if ping -c 1 -W 1 $host > /dev/null 2>&1; then
    echo "$host is reachable"
  else
    echo "$host is unreachable"
  fi
done

Output

google.com is reachable
github.com is reachable
invalid.host is unreachable

Dry Run

Let's trace pinging 'google.com' and 'invalid.host' through the script

1

Set hosts variable

hosts="google.com invalid.host"

2

Start loop with host=google.com

ping -c 1 -W 1 google.com runs and succeeds

3

Print result for google.com

Output: google.com is reachable

4

Next loop with host=invalid.host

ping -c 1 -W 1 invalid.host runs and fails

5

Print result for invalid.host

Output: invalid.host is unreachable

Host	Ping Result	Output
google.com	Success	google.com is reachable
invalid.host	Fail	invalid.host is unreachable

Why This Works

Step 1: Loop over hosts

The script uses a for loop to go through each host in the list one by one.

Step 2: Ping each host once

It runs ping -c 1 -W 1 to send one ping and wait 1 second for a reply, checking if the host is reachable.

Step 3: Check ping success

If ping returns success, the script prints the host is reachable; otherwise, it prints unreachable.

Alternative Approaches

Using a file with hosts

bash

#!/bin/bash
while read -r host; do
  if ping -c 1 -W 1 "$host" > /dev/null 2>&1; then
    echo "$host is reachable"
  else
    echo "$host is unreachable"
  fi
done < hosts.txt

Reads hosts from a file line by line, useful for many hosts but requires a file.

Parallel ping with background jobs

bash

#!/bin/bash
hosts="google.com github.com invalid.host"
for host in $hosts; do
  (ping -c 1 -W 1 $host > /dev/null 2>&1 && echo "$host is reachable" || echo "$host is unreachable") &
done
wait

Pings hosts in parallel to speed up, but output order may vary.

Using fping tool

bash

fping -c1 -t300 google.com github.com invalid.host

fping is a specialized tool for pinging multiple hosts efficiently but may need installation.

Complexity: O(n) time, O(1) space

Time Complexity

The script pings each host once, so time grows linearly with the number of hosts.

Space Complexity

The script uses constant extra memory regardless of the number of hosts.

Which Approach is Fastest?

Parallel pinging runs faster but is more complex; sequential pinging is simpler and easier to understand.

Approach	Time	Space	Best For
Sequential ping loop	O(n)	O(1)	Simple scripts with few hosts
Parallel ping with background jobs	O(1) to O(n) depending on system	O(n)	Speeding up many hosts
fping tool	O(n)	O(1)	Efficient multi-host pinging with external tool