sv.h Scalar value header
t/README Instructions for regression tests
t/TEST The regression tester
+t/TestInit.pm Preamble library for core tests
t/base/commonsense.t See if configuration meets basic needs
t/base/cond.t See if conditionals work
t/base/if.t See if if works
t/pragma/warn/utf8 Tests for utf8.c for warnings.t
t/pragma/warn/util Tests for util.c for warnings.t
t/pragma/warnings.t See if warning controls work
+t/run/runenv.t Test if perl honors its environment variables.
taint.c Tainting code
thrdvar.h Per-thread variables
thread.h Threading header