I want to delete anything that follows a
% to the end of the line. Using
cat /tmp/foo.txt | sed 's/%.*$//'
works great with one exception: I want to ignore any escaped percent signs
\%. So with the following file saved as
abcd %123 xyz \%xyz xyz \%xyz %123
the output I want is
abcd xyz \%xyz xyz \%xyz
What is the appropriate regular exception handling to do this?