I tried
Code:
$ sed 's/gratefull/grate\055full/' file1 > file2
$ sed 's/gratefull/grate\o055full/' file1 > file2
$ sed 's/gratefull/grate\0x2dfull/' file1 > file2
and many other permutations. They don't work. OpenBSD's sed doesn't seem to allow the programmatic insertion of an abitrary hex character. Not even '\t' or '\n', etc. like GNU sed does. Kind of a bummer. Maybe there's a binary sed available?