If you're using BSD UNIX, the ls command gives you some help; it
will convert all non-printing characters to a question mark (
you some idea that something funny is there.
 The -q option is the default only when ls's standard output is a terminal. If you pipe the output or redirect it to a file, remember to add -q.
This shows that there are two non-printing characters between
cd. To delete (or rename) this file, you can use a wildcard
pattern like ab??cd.
NOTE: BE CAREFUL. When I was new to UNIX, I once accidentally generated a lot of weird filenames. ls told me that they all began with ????, so I naively typed
rm ????*. That's when my troubles began. See article 23.2 for the rest of the gruesome story. (I spent the next day and night trying to undo the damage.) THE MORAL IS: It's always a good idea to use echo to test filenames with wildcards in them.
If you're using System V UNIX, you have a different set of problems. System V's ls doesn't convert the non-printing characters to question marks. In fact, it doesn't do anything at all - it just spits these weird characters at your terminal, which can respond in any number of strange and hostile ways. Most of the non-printing characters have special meanings - ranging from "don't take any more input" to "clear the screen."
 On BSD, pipe the ls -q output throughto see what the non-printing characters are.
This shows that the non-printing characters have octal values 13 and 14, respectively. If you look up these values in an, you will see that they correspond to CTRL-k and CTRL-l. And - if you think about what's happening - you'll realize that CTRL-l is a formfeed character, which tells many terminals to clear the screen. That's why the regular ls command behaved so strangely.
Once you know what you're dealing with, you can use a wildcard pattern to delete or rename the file.