I want to read line n1->n2 from file foo.c into the current buffer.
I tried: 147,227r /path/to/foo/foo.c
But I get: \"E16: Invalid range\", though I
You can do it in pure Vimscript, without having to use an external tool like sed:
:put =readfile('/path/to/foo/foo.c')[146:226]
Note that we must decrement one from the line numbers because arrays start from 0 while line numbers start from 1.
Disadvantages: This solution is 7 characters longer than the accepted answer. It will temporarily read the entire file into memory, which could be a concern if that file is huge.