When writing any kind of log files you can of course show them on the console by opening them in any kind of editor be it
less or just a simple
cat. But you need to run the command every single time you run a process that writes something into the file.
A better way is to use
tail with the
-f option. With it you jump into the file and stay there. Any changes into the file will be shown immediately:
$ tail -f /tmp/error.log