1. 고급 시스템 프로그래밍 실습 매뉴얼
Lab3 list 명령어

2. lab3 다양한 옵션을 갖는 파일 리스트 명령어 구현 list [-option] {file or directory}*
For each directory, lists contents of directory
For each file that is an ordinary file, list repeats its name and any other information requested
강의노트 listfiles.c를 확장한다.
다음 6개 옵션을 구현한다.

3. OPTIONS
-l Lists in long format, giving mode, ACL indication, number of links,
owner, group, size in bytes, and time of last modification for each file.
list -l (the long list) prints its output as follows:
-rwxrwxrwx+ 1 smith dev May 16 9:42 part2
-a Lists all entries, including those that begin with a dot (.), which are normally not listed.
-F Marks directories with a trailing slash (/), executable files with a
trailing asterisk (*), FIFOs with a trailing vertical bar (|), symbolic links with a trailing 'at' sign and AF_UNIX address family sockets
with a trailing equals sign (=).
-h All sizes are scaled to a human readable format, for example, 14K,
234M, 2.7G, or 3.0T. Scaling is done by repetitively dividing by 1024.
-R Recursively lists subdirectories encountered.
-t Sorts by time stamp (latest first) instead of by name. The default is the
last modification time.