...hell session, on a system with glibc 2.10, shows some examples of what we would see: $ cc ftm.c $ ./a.out _POSIX_SOURCE defined _POSIX_C_SOURCE defined: 200809L _BSD_SOURCE defi…...hell session, on a system with glibc 2.10, shows some examples of what we would see: $ cc ftm.c $ ./a.out _POSIX_SOURCE defined _POSIX_C_SOURCE defined: 200809L _BSD_SOURCE defi…...r errors with features like compiler warnings, static analyzers, and _FORTIFY_SOURCE (see ftm (7)). Keeping the code simple helps these overflow-detection features be more preci…