The existence of special characters (particularly
!) can be a pain;
you may often need to type commands that have exclamation points in them,
and occasionally need commands with carets (
These get the C shell
confused unless you "quote" them properly. If you use these special
characters often, you can choose different ones by setting
the histchars variable.
histchars is a two-character string; the first character
replaces the exclamation point (the "history" character), and the
second character replaces the caret (the
ls file*file1 file2 file3 %
@@Repeat previous command (was
!!) ls file* file1 file2 file3 %
#file#data#Edit previous command (was
^file^data^) ls data* data4 data5
An obvious point: you can set histchars to any characters you
like, but it's a good idea to choose characters that you aren't likely
to use often on command lines.
Two good choices might be
# (hash mark) and
 In the C shell,
#is a only in non-interactive shells. Using it as a history character doesn't conflict because history isn't enabled in non-interactive shells.