CHA2
....\1
....\.\demo.c
....\.\demo.h
....\.\test1.c
....\.\test2.c
....\2
....\.\demo.c
....\.\demo.h
....\.\read.c
....\.\write.c
....\3
....\.\demo.c
....\.\demo.h
....\4
....\.\demo.c
....\.\demo.h
....\5
....\.\demo.c
....\6
....\.\demo.c