Searching for a particular string using Regex in Bash/Shell Scripting - linux

Question

I am trying to echo out the the average round trip time for 4 ICMP echo/echo rely packets (in ms) for a website like google. This is my code as of now.
echo "$(ping -c 4 google.com | grep '??????')"
Pinging the website works but I have no idea how to echo out only the average round trip time. I have only used Regex for validation on web forms, but I haven't used it in awhile. I assume I can use Regex to find only what I am searching for, but if there is a better way of doing this, that would also be great. I am writing this using shell scripting for linux ubuntu
This is an example of the output. The only part of this I need is the part at the bottom where it says rtt min/avg/max/mdev = 14.556/14.579/14.614/0.088 ms.
PING google.com (142.250.74.238) 56(84) bytes of data.
64 bytes from par10s40-in-f14.1e100.net (142.250.74.238): icmp_seq=1 ttl=108 tim e=14.5 ms
64 bytes from par10s40-in-f14.1e100.net (142.250.74.238): icmp_seq=2 ttl=108 tim e=14.5 ms
64 bytes from par10s40-in-f14.1e100.net (142.250.74.238): icmp_seq=3 ttl=108 time=14.5 ms
64 bytes from par10s40-in-f14.1e100.net (142.250.74.238): icmp_seq=4 ttl=108 time=14.6 ms
--- google.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3003ms
rtt min/avg/max/mdev = 14.556/14.579/14.614/0.088 ms

Answer 1

Assuming the ping output looks like the following:
$ ping -c 4 google.com
PING google.com (172.217.14.238): 56 data bytes
64 bytes from 172.217.14.238: icmp_seq=0 ttl=118 time=78.019 ms
64 bytes from 172.217.14.238: icmp_seq=1 ttl=118 time=62.416 ms
64 bytes from 172.217.14.238: icmp_seq=2 ttl=118 time=63.019 ms
64 bytes from 172.217.14.238: icmp_seq=3 ttl=118 time=62.415 ms
--- google.com ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max/stddev = 62.415/66.467/78.019/6.674 ms
In this scenario the average time is 66.467 (ms)
One awk solution:
awk '/avg/ {split($0,arr,"/"); print arr[5]}'
Where:
/avg/ - look for line with the string avg
split($0,arr,"/") - split the line using a forward slash (/) as the delimiter, place the segments in the arr[] array
print arr[5] - print the 5th element of the arr[] array
Combining with the ping:
ping -c 4 google.com | awk '/avg/ {split($0,arr,"/"); print arr[5]}'
66.467
And if we need to include the measurement of time (ms in this case), we can also print the last field of the line that contains the string avg, eg:
ping -c 4 google.com | awk '/avg/ {split($0,arr,"/"); print arr[5],$NF}'
66.467 ms
NOTES:
OP may need to tweak the awk command if their ping output is in a different format
obviously (?) each time the ping is run we're likely to get a slightly different value.
if OP wants to be 100% certain of the value then the ping command output should be saved to a file (or variable) and then run the awk command against said file (or variable)