Paste, join and expand text

A few new commands for manipulating text that I never knew about:

• paste
  • allows one to “paste” two files side by side. First row’s contents of fileB.txt will be to the left of the first row’s contents of fileA.txt, and on down the line.
• join
  • Imagine mysql or something, this “joins” two (or maybe more) files together on a common field in whitespace-separated lines. It ignores unique values (at least by default)
• expand
  • I don’t know what I’d ever use this for, but it will convert tabs into spaces. Makes a file fixed-width, rather than tabbed. For whatever one needs that for.

• text manipulation