rvinterf: begin change to backslash escape output format Right now throughout the rvinterf suite, any time we emit output that is expected to be ASCII, but may contain non-printable garbage, we use 'cat -v' form of garbage character representation. Unfortunately, this transformation is lossy (can't be reversed 100% reliably in the user's wetware), hence we would like to migrate to C-style backslash escapes, including doubling of any already-present backslashes - this escape mechanism is lossless. Begin this change by converting the output of RV and L1 traces in rvinterf and rvtdump.

This host side library contains common modules for tools like fc-tmsh and
g23sh which operate asynchronously.  This code has been factored out of
fc-tmsh.