The programs in this directory are introduced in Chapter 2 in the 
order given below.  
get_libc_version_demo.c
gettid_demo.c
perror_demo.c
printargs1.c
printargs2.c
printargs3.c
environ_demo.c
getenv_demo.c
risky_getenv.c
usagecheck_demo.c
progname_demo.c
basename_demo.c
gethostname_demo.c
getopt_demo.c
strtol_demo.c
str2int.c
strerror_demo.c

You can use the following two programs for testing the get_int() and
get_long() functions in the libspl.a library.
test_get_int.c
test_get_long.c
