I'm finally learning how to use sed and I can't find an answer to this but I'm sure it's basic.

I have a file name of student names and their homerooms. The 3rd year students just graduated so I want to change their homeroom status to 'graduated'. This is a sample:

Yuko Myoji 31
Maiko Nanikashira 31
Ema Shiranai 32
Airi Dosuru 33


If I run sed s/31/graduated/g it will change all students in 31 to graduated, but how do I do that for 3x (i.e., students in homerooms 31, 32, 33 and 34?)

I tried sed s/31/graduate/g name.txt >> updatednames.txt, then did the same thing for s/32, s/33 and s/34, but the file repeats the whole list each time, so I know I'm doing something wrong.

In utilities like SED, what you call "wildcards" are part of the syntax of Regular Expressions (AKA Regexes).

In your example, you could use:
For good tutorials on SED, Regexes, and more, go here:
http://www.grymoire.com/Unix/Sed.html

Yeah, I knew I didn't have the lingo quite right. I still tend to think of everything I do at the command line as mere commands with switches and wildcards. I forget that grep, sed,　etc are actually using expressions. Thanks for that and for the code! Big help!

Actually, even the bash 'wildcards' are in fact expressions; there's more to them than you think..

You're right, I need to stop being so myopic. Bash is really like a mini-programming environment, anyway, right?

BASH is a very capable scripting language, although possibly not the easiest to learn...