Here is an example of a check if a file exists on the remote server and takes action locally, inside a shell script.
if [ $(ssh codetryout [[ -f /etc/passwd ]];echo $?) -eq 0 ]; then echo "Remote file exists" fi
Script explanation, line by line:
The remote testing section is:
ssh codetryout [[ -f /etc/passwd ]]
This command will ssh to the host (server) “codetryout” and test if the file “/etc/passwd” exists
This will echo the return status of ssh command file check, will return 0 if it was a success, 1 if the file was not existing. To learn more about bash return codes (error codes) please check this page: codetryout.com/bash-last-command-return-code/