On Tue, Nov 15, 2016 at 3:33 PM, Paul Eggert <egg...@cs.ucla.edu> wrote: > On 11/15/2016 03:13 PM, Jim Meyering wrote: >> >> We should retain the optimization when reading from stdin that is >> neither a pipe nor a tty. > > I am toying with the idea of retaining the optimization only if lseek-to-EOF > succeeds, a heuristic that is a bit more restrictive. This arguably would > conform better to the POSIX requirement that when grep exits "the file > offset in the open file description is properly positioned just past the > last byte processed by the utility." See the INPUT FILES section of > <http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap01.html#tag_17_04>.
I like it. That would make the offset in the input file predictable in those cases.
