Hello all. Is there a command to copy the contents of one file into another file as the first line?
Welcome to the forum.
Your request is unclear. Please become accustomed to provide decent context info of your problem.
It is always helpful to carefully and detailedly phrase a request, and to support it with system info like OS and shell, related environment (variables, options), preferred tools, adequate (representative) sample input and desired output data and the logics connecting the two including your own attempts at a solution, and, if existent, system (error) messages verbatim, to avoid ambiguities and keep people from guessing.