This is an ext2 file system simulator that works on memory created by NCLAB21st.
$ make
$ ./shell
NCLAB21 : [/]# format
NCLAB21 : [/]# mount
NCLAB21 : [/]# ~~(command)
NCLAB21 : [/]# format
NCLAB21 : [/]# mount
NCLAB21 : [/]# fill [file name] [size] [option]
option : -c, -a
NCLAB21 : [/]# touch [file name]
NCLAB21 : [/]# rm [file name]
NCLAB21 : [/]# ls
NCLAB21 : [/]# cat [file name]
NCLAB21 : [/]# mkdir [file name]
NCLAB21 : [/]# rmdir [file name]
NCLAB21 : [/]# df