def METHOD_NAME(cmds,inp_file,outp_file):
    if (os.path.exists(inp_file)):
        with xopen(outp_file,"w") as out_file:
            with xopen(inp_file) as in_file:
                for line in in_file:
                    if line.startswith("<!-- PLACEHOLDER -->"):
                        out_file.write(cmds)
                    else:
                        out_file.write(line)