11.16 Instead of Changing History Characters

If you need to use ! (or your current history character) for a command (most often, a uucp or mail ( 1.33 ) command), you can type a backslash ( \ ) before each history character. You can also drop into the Bourne shell quickly (assuming that you aren't on a system that has replaced the real Bourne shell with bash ). Either of these are probably easier than changing histchars . For example:

% 

mail ora\!ishtar\!sally < file1


Quote the !s
 % 

sh   


Start the Bourne shell
 $ 

mail ora!ishtar!sally < file1


! not special here
 $ 

exit   


Quit the Bourne shell
 %   
And back to the C shell

The original Bourne shell doesn't have any kind of history substitution, so ! doesn't mean anything special; it's just a regular character.

By the way, if you have a window system, you can probably copy and paste the command line instead of using shell history.