Merge pull request #162 from scottcpeterson/patch-14

?.txt instead of *.txt for loop example

Author: jmjamison

_episodes/04-loops.md

@@ -45,7 +45,7 @@ We can apply this to our example like this:
 
 
 ~~~
-$ for filename in *.txt
+$ for filename in ?.txt
 > do
 >    echo "$filename"
 >    cp "$filename" backup_"$filename"