Your script should work on similar input files. Write a "sed" script which transforms a text file proper C Here is an input file The first three lines should be ignored Don't include them in your output So you'll need to tell 'sed' to ignore them # This is a comment BEGIN HELLO END # so is this! Copy and paste that into a file on your machine, and write a "sed script to turn it into the following: #include int main() printf("hello, world "); You will need to: Delete the first three lines of the input Delete anything after #, leaving no empty lines behind . Convert BEGIN into the "#include" and "main" lines Convert HELLO into the "printf" . Convert END into the trailing ")