Je me souviens jamais des paramètres (pourtant pas si compliqués):

# Server
iperf3 -s

#Client
iperf3 -c <my-ip> test

Reminders about some bash syntaxes I never remember :)

Read a file, line by line

while IFS= read -r line; do echo "$line"; done < file.txt

Curl with headers (in request and response)/

curl -i -X POST "http://example.com" -H "header: value" -H "another-header: value"

Cat some files in a folder (adding carriage return) (in a watch)

Here, every files matching folder-*/subfolder/file-*.txt

watch -n 1 'for file in folder-*/subfolder/file-*.txt; do cat $file; echo; done'