The less command is one I use a lot. It shows you the content stored inside a file, in a nice and interactive UI.

Usage: less <filename>.

Once you are inside a less session, you can quit by pressing q.

You can navigate the file contents using the up and down keys, or using the space bar and b to navigate page by page. You can also jump to the end of the file pressing G and jump back to the start pressing g.

You can search contents inside the file by pressing / and typing a word to search. This searches forward. You can search backwards using the ? symbol and typing a word.

This command just visualises the file’s content. You can directly open an editor by pressing v. It will use the system editor, which in most cases is vim.

Pressing the F key enters follow mode, or watch mode. When the file is changed by someone else, like from another program, you get to see the changes live. By default this is not happening, and you only see the file version at the time you opened it. You need to press ctrl-C to quit this mode. In this case the behaviour is similar to running the tail -f <filename> command.

You can open multiple files, and navigate through them using :n (to go to the next file) and :p (to go to the previous).

This command works on Linux, macOS, WSL, and anywhere you have a UNIX environment