How can I "page down" in the terminal?
In addition to VxJasonxV’s answer (which is correct), if you want to modify your terminal behavior so using up or down does a pageup/pagedown in vim (and others), you can go to:
Terminal -> Preferences -> Click on the Settings Toolbar, then the Keyboard Tab.
Add a new keys like this: (showing one example below)
Here’s an example with the “Cursor up”:
Now you can press Up/Down and it will do the pageup/down. I suggest you add a modifier (like Control). Sadly, you can’t use the “Fn” key as a modifier.
Note: By default, Control + Cursor Left is delete until the end of the line and control+cursor right is insert (in vim at least), so you can use another modifier if you don’t want to change those.
There are two answers to this question.
The first is globally useable. I'll assume you're on a narrow/laptop keyboard. In those instances, Fn+Down ▼ acts as Page Down, and just to expand that thought out entirely:
This will not work properly in some applications. Those that come to mind are things like
The second half of the answer is one that I can't answer without more detail.
If I haven't answered your question, you will need to elaborate on it, heavily.
In order to send a page up/down keystroke to the application, as opposed to scrolling Terminal's window, hold down the shift key while pressing your page up/down keys (or fn-arrows as appropriate for your keyboard).