1. When in doubt ..
man commands
Samples: $ man talk
$ man grep
2. What’s my Unix system name, OS,CPU?
$ uname -a
Sample result:
SunOS hostname 5.8 Generic_108528-06 sun4u sparc SUNW, Ultra-5_10
3. Where am I (current working directory)?
$ pwd /export/home/user
4. Who am I?
$ who ; returns all users who logged on to the system.
$ who am i ; returns only your log in name and time.
5. What is my hostname?
$ hostname
6. What is my account info?
$ finger [account] ; to see login name, real name, TTY, idle time, when & where
7. What is my default printer?
$ lpstat -t ; shows printer statistic and status
8. When pressing BackSpace it shows ^H, how do I set it to work correctly?
$ stty erasectrl-v + bs ;press ctrl-v and back space button
9. Change directory
$ cd /usr/bin
$ cd ~+ ; ~+ = cwd or “.” wherein ~- previous working directory
$ cd $HOME ; changes directory to your home folder = cd ~
$ cd ../../hw1
$ cd .. ; moves one level up from your current working directory
10. List contents of the directory
$ ls *[x,X]* ; returns a listing of files that contain x or X in the file name
$ ls -R ; lists recursively that includes subdirectories
$ ls -li ; displays long listing with inode number, or -a to list hidden files
11. File permissions
$ chmod u+x, g-r myfileadd execute permission to user, remove read from group
$ chmod u=rx, g=r, o=file ; allows user to read and execute, group to read, no
read, write and execute for others
$ chmod a=rxfile ; allows user, group and others to read and execute
$ chmod 754 myfile7-> 111 in binary represents rwx for user
5-> 101 in binary represents r-x for group
4-> 100 in binary represents r– for others
12. Read text file(s)
$ catmyfile ; alternately, you can use more myfile
$ catmyfile news mail ; read multiple files
$ cat *ing
13. Copy file(s)
$ cpmyfile newfile
$ cp * ../hw
$ cp -r /home/mydir /home/newdir ; copies everything in mydir to newdir
$ cp -p source destination ; retains existing permissions (copy ACL along)
$ cp -i source destination ; does not overwrite an existing file
14. Move files to another directory
$ mv * /home/my_account
$ mvmyfile $HOME
15. Delete file(s)
$ rm myfile
$ rmmyfile? ; removes myfile1, myfile2, myfile3 and so on.
16. Make a directory
$ mkdirmydir
17. Delete an empty directory
$ rmdirmydir
18. Delete a directory that contains files and subdirectories
$ rm-rmydir ; removes recursively all files and subdirectories
19. Symbolic link (can span/accross file systems)
$ ln -sfile1link1 ; uses ls -li to see link1-> file1 with 2 different inodes.
symbolic link always has a=rwx permissions
20. Hard link (files contain the same inode, can not span file systems)
$ lnfile1 link1 ; allows the same file to be accessed under different names
SAP Basis Administrator 