sed -e 's;//.*$;;'

sed -e 's/\/\/.*$//'

#!/usr/bin/sed -nf

# This first case takes care of the following two 
# scenarios:
# 1:  /* a comment spanning an entire line */
# 2:  int code = 1; /* code + comment on same line */
# We are saying search between /* and */, and then
# substitute that for "nothing". So the syntax
# /start/,/end/ searches between start and end.
/\/\*/,/\*\// {
  s/\/\*.*\*\///g
}

# take care of multiline comments
# This deletes any lines inclusive. So if a multiline
# comment started on a line with code also, this would
# break.
/\/\*/,/\*\// {
  d
}

# now for // style comments
# This just says substitute // followed by any number
# of anything, followed by the end of the line, with nothing.
s/\/\/.*$//g

# print the rest
p