-APUE-:
fig12.4, creating a thread in the detached state.
fig12.8, using a recursive mutex.
-APUE-:
fig12.11, a nonreentrant version of getenv.
fig12.12, a reentrant(thread-safe) version of getenv.
-APUE-:
fig12.13, a thread-safe, compatible version of getenv.