Unix: File System and Utilities

Tom Kelliher, CS23

Feb. 12, 1996

To correct the telnet ``deficiencies'' in the Math/CS Lab:

• Click: Setup, Transports, Edit..., then choose the radio button so that the emulator sends CRLF

The Filesystem and Files

Part of the filesystem hierarchy on keystone:

1. Navigating: cd
   • The current directory: .
   • The parent directory: ..
   • Absolute paths
   • Relative paths
2. Where am I: pwd
3. Extending the filesystem: mkdir (permissions)
4. Contracting the filesystem: rmdir (empty)
5. Looking around: ls (options: -a, -l, etc.)
6. Quick and dirty viewing and creating: cat
7. Nicer file viewing: more or less ( PAGER)
8. Rearranging: cp and mv
9. Cleaning up: rm (safety net)
10. Printing:
    • lpr
    • lpq
    • lprm kelliher
    • lp, lpche
    • lpr switches: -P, -h ( lpr -Plpche hw1.cc)
11. Finding programs: which, whereis
12. Categorizing file: file
13. Comparing files: diff, cmp

Filesystem Permissions

Owner, group

Permission categories:

• Owner
• Group
• World

Permissions:

• Read
• Write
• Execute/Search

1. Default permissions: umask
2. Changing permissions: chmod
   • Absolutely: chmod 755 ~kelliher/pub
   • Symbolically: chmod go+rx ~kelliher/pub

Utilities

1. Globbing files: tar
2. Compressing and uncompressing files: gzip, gunzip, gzcat
3. User information: finger elvis Send mail to kelliher AT DOMAIN abacus
4. What's running: ps, top
5. Getting away with murder: kill ( ctrl-c for foreground)