Chapter 7 / 3 - correct sys_stubs.h.
Chapter 7 / 3 - .gitignore.
Chapter 7 / 3 - correct permissions error.
Chapter 7 / 3 - correct mkstemp()

by undefining __STRICT_ANSI__,
which shouldn't have been defined without -ansi.
Chapter 7 / 5
Chapter 7 / 6
Chapter 7 / 7 - one test not passing.
Chapter 7 / 7 - fix subtle error involving

strlen() vs sizeof() and lack of terminating zero.
Chapter 7 / 7 - RAII idiom

let fd close itself upon destruction.
Chapter 7 / 8
Chapter 7 / 10 - a bit overdone ;-)

Nothing new in Chapter 7 / 9.
Chapter 7 / 11 - not working.
Chapter 7 / 11 - refactored

and working.
Chapter 7 / 11 - refactored

to rid the macro of stuff that should be explicit.
Chapter 7 / 12
Chapter 7 / 12 - attempt at PersistenceTest.cpp.