Commonly, we can use test to check the conditions based around files. For example, to test whether a file is present or not, we can use the -e option. The following command will test the existence of the /etc/hosts file:
test -e /etc/hosts
We can run this test again, but this time check that the file not only exists but is a regular file as opposed to having some special purpose. Specific file types can be directories, pipes, and links, among others. The option for a regular file is -f:
$ test -f /etc/hosts
