UNIX UTILITY PACKAGE

1. UNIX UTILITY PACKAGE • Shell Simulator • Added Shell Commands • File System Explorer ( LNC ) • System Information • Process Tree Viewer

2. What Is Shell ? Shell provides a protective covering for the kernel . A UNIX shell provides a protective outer covering. To protect the user from the complexity of the kernel, and to protect the kernel from the user, a protective shell is built around the kernel. The user makes requests to a shell, which interprets them, and passes them on to the kernel.

3. Shell Comparison Most contemporary versions of UNIX provide all three shells • Bourne Shell • C Shell • Korn Shell

4. Functions Of Shell • Command line interpretation • Program initiation • Input-output redirection • Pipeline connection • Substitution of filenames • Maintenance of variables • Environment control • Shell programming

5. Our Shell Commands

6. help The list of implemented shell commands with a description

7. ls ls - Displays entries in the current working directory -l -Displays the file modes and no of links to the file,owner name, group name, size of the file (in bytes)time stamp and the file name. -a - Displays all entries including hidden files -r - Displays all entries in reverse order -i - Displays all file names with their inodes no -i <path> - Displays the inode no of the file name specified -ss - Displays the file names in sorted order on size types - Displays all file names with their types

8. Shells Display existing shells in the system by reading and printing /etc/shells

9. Mount Display all devices and file systems mounted in the system by opening and reading /etc/mtab We use mntent structure and setmntent( )getmntent( )for reading the file

10. Mount continued FILE *fp; struct mntent *mn; fp=setmntent("/etc/mtab","r"); mn=getmntent(fp); while (mn!= NULL) { printf("%s on %s",mn->mnt_fsname,mn->mnt_dir); printf("type %s (%s)",mn->mnt_type,mn->mnt_opts); mn=getmntent(fp); } endmntent(fp);

11. Sysconfig Long sysconf ( int name ) Get system limits or run time options We pass macros and get integer Macros can be : _SC_ARG_MAX , _SC_CLK_TCK , _SC_OPEN_MAX , _SC_STREAM_MAX ,…

12. Cpu We open the file /proc/cpuinfoand simply print it for geeting info about the cpu

13. sysinfo Using sysinfo structure and Sysinfo system call we get info about processes ,memory ,… int sysinfo(struct sysinfo *info);

14. Sysinfo continued struct sysinfo { long uptime; /* Seconds since boot */ unsigned long loads[3]; /* 1, 5, 15 min load averages */ unsigned long totalram; /* Total usable main memory size */ unsigned long freeram; /* Available memory size */ unsigned long sharedram; /* Amount of shared memory */ unsigned long bufferram; /* Memory used by buffers */ unsigned long totalswap; /* Total swap space size */ unsigned long freeswap; /* swap space still available */ unsigned short procs; /* Number of current processes */ ….. };

15. fsblk We want to get file system block size. The whole thing is : struct stat st;stat("/",&st); /* current fs */printf("%d",st.st_blksize);

16. Am Gives info about you ; with the help of getuid() , getlogin ()

17. Inode<path> Using stat structure and stat system call we get info about inode of the specified file.. struct stat { dev_t st_dev; /* device */ ino_t st_ino; /* inode */ mode_t st_mode; /* protection */ dev_t st_rdev; /* device type (if inode device) */ off_t st_size; /* total size, in bytes */ unsigned long st_blksize; /* blocksize for I/O */ unsigned long st_blocks; /* allocated blocks*/ time_t st_atime; /* time of last access */ time_t st_mtime; /* time of last modification */ time_t st_ctime; /* time of last change */ };

18. filesys Using struct statfs and statfs system call we get info about file system. int statfs(const char *path, struct statfs *buf); int fstatfs(int fd, struct statfs *buf);

19. Filesys continued struct statfs { long f_type;/* type of fs */ long f_bsize; /* opt transfer block size */ long f_blocks; /* total data blocks in fs */ long f_bfree; /* free blocks in fs */ long f_bavail; /* free blocks avail to non-superuser */ long f_files; /* total file nodes in fs */ long f_ffree; /* free file nodes in fs */ fsid_t f_fsid; /* file system id */ long f_namelen; /* maxlength of filenames */ long f_spare[6]; /* spare for later */ };

20. Who , Who -a Using /etc/passwd and /var/run/utmp and structures utmp and passwd we get logged in users or all users. struct utmp { short ut_type; /* type of login */ pid_t ut_pid; /* pid of login process */ char ut_line[UT_LINESIZE]; /* device name of tty - "/dev/" */ char ut_user[UT_NAMESIZE]; /* user name */ char ut_host[UT_HOSTSIZE]; /* hostname for remote login */ struct timeval ut_tv; /* time entry was made. */ int32_t ut_addr_v6[4]; /* IP address of remote host. */ ….. };

21. Who –a continued struct passwd { char *pw_name; /* user name */ char *pw_passwd; /* user password */ uid_t pw_uid; /* user id */ gid_t pw_gid; /* group id */ char *pw_gecos; /* real name */ char *pw_dir; /* home directory */ char *pw_shell; /* shell program */ };

22. Time We get useful info by using tm structure and localtime() , time() system calls struct tm { int tm_sec; /* seconds */ int tm_min; /* minutes */ int tm_hour; /* hours */ int tm_mday; /* day of the month */ int tm_mon; /* month */ int tm_year; /* year */ int tm_wday; /* day of the week */ int tm_yday; /* day in the year */ int tm_isdst; /* daylight saving time */ };

23. Cd .. Cd\ cd <path> OBVIOUSLY with chdir( ) !

24. Help,Time,Cd,Shells • Help: About all shell commands that we have implemented • Time : Using tm structure we get time , date , day of week and day in year • Cd : File system traversal. It can handle cd \ and cd .. and cd < path > • Shells : Using /etc/shells , we list existing shells in system

25. Who , Who –a , mount , inode • Who: Using /var/run/utmp we list logged on users • Who –a: Using /etc/passwd we list all who have account • Mount: Using /etc/mtab we list all mounted filesystems in mount table • Inode < path >: Inode table of file as in stat structure

26. Filesys , sysinfo , Sysconf , Fsblk • Filesys: Using statfs structure and system call we get info about file system • Sysinfo: Using sysinfo structure and system call we get info about system • Sysconf: Using sysconf() system call we get information about system configuration • Fsblk: File system block size

27. Ls , types , lnc , cpu , am • Lnc: Is a file systtem explorer • Ls: Has been implemented with –i , -a , -ss , -r , -l flags • Types: All file with their types • Cpu: CPU information • Am : Current user information

28. Late Night Commander (LNC) • GUI for file system exploration • Ability to operation of files like copy , delete , remove ,… • Uses Curses • Gives information about files and file system • It can have shell capabilities

29. Curses The curses package is a subroutine library for terminal-independent screen-painting and input-event handling which presents a high-level screen model to the programmer, hiding differences between terminal types and doing automatic optimization of output to change one screen-full of text into another.

30. Curses In 10 Lines !! WINDOW *windir; initscr(); start_color(); init_pair(1,COLOR_WHITE,COLOR_BLUE); windir=newwin(26,70,3,0); box(windir,ACS_VLINE,ACS_HLINE); wattrset(windir,COLOR_PAIR(1)); mvwprintw(windir,1,1," BE BRIEF “); wrefresh(windir); endwin();

31. Advantages Of The Project ! 1. Portability 2. Low requirements 3. User friendly 4. All advantages of shells applies here ! 5. All advantages of a file system explorer applies to LNC ! 6. Our added shell commands

32. Limitataions • Not a complete shell • LNC and big directories • LNC not complete • Colors are not that properly implemented • Dependence on the underlaying shell • Bugs !

33. THANK YOU !