csh and single quotes

In csh, using quotes in a quoted string can be tricky, especially if the string contains both single and double quotes. If you use single quotes to quote the string, use ‘\’’ (a single quote, a backslash followed by two single quotes) where you want to insert a single quote:

% echo 'testing'
testing
% echo 'test'ing'
Unmatched '.
% echo 'test\'ing'
Unmatched '.
% echo 'test\\'ing'
Unmatched '.
% echo 'test''ing'
testing
% echo 'test'\''ing'
test'ing