2.9BSD/usr/lib/learn/files/L5.1c

#print
The "?" may appear anywhere in the name.
For example you can type
  a?bc
to match the list of names
  axbc, aybc, a3bc
and so forth.
But the number of characters must always agree.
How many of the following file names
are matched by "x?xx"?
  x1xx, y1xx, x1xxa, xxx
Type "answer N" where N is the number of matching names.
You can experiment in the current directory to
check your answer before typing it.
#create x1xx
#create x1xxa
#create y1xx
#create xxx
#copyin
#user
#uncopyin
#match 1
#log
#next
5.1d 0
5.1e 5