Listing Hidden Files and Folders
The "ls" command has many options that, when passed, affect the output. For example, the "-a" option will show all files and folders, including hidden ones.
Let's try it by typing "ls -a Downloads"
This time, we see a few more items in the list. The "." and ".." items simply represent the current directory and one level up respectively. I'll talk more about that in the next section.
We also see a few files that start with a ".". These are hidden files, and are not included in the "ls" command by default. You'll also notice that they are not shown in Finder by default. The ".DS_Store" file is a metadata file that the Mac operating system creates in each directory and contains information about that directory and its contents. (Windows machines also have a similar file.) The ".hiddenfile" file is actually just a dummy file that I created.
There are other options that can be passed to the "ls" command, and if you're interested, I'd encourage you to Google them, or take a look at this Wikipedia article but I'm just going to show you one more, because I almost never use the -a option without it.
It's the "-l" option, and if I type "ls -l Downloads" you can see it in action.
The "-l" option shows the list in "long format" which includes the permissions, number of hard links, owner, group, size, last-modified date and the filename.
Now, I mentioned that I use these commands together, so I'll show you how to do that. You could enter each option separately like this "ls -a -l Downloads", but you can actually combine options, which means you can simply type "ls -al Downloads", so that's what I'll do.
Now we see the long format of all files in this directory, including hidden files. In general, when I need to list hidden files, this is the command I use.