Updating an object file using BFD interface，andmodify the contents of the.text section of a.o file

Question

Now I need to modify the contents of the.text section of a.o file. When I open the abfd with bfd_openr and get the contents of the text section through bfd_get_section_contents and modify it, I assign the modified value to the contents of the text segment but when I bfd_close(abfd) is not modified, what should I do?

Save the result in the original file