| Command | Parameter | Description |
cp |
Copy files. Syntax: cp filename destination |
|
cp |
-R |
Copy files, including files in subdirectories |
df |
Display empty disk space | |
du |
Display how much disk space files and directories occupies in bytes | |
dmesg |
Displays the hardware information you see during the bootup sequence. | |
du |
-h |
Display how much disk space files and directories occupies in K or MB |
find |
Find files in the current directory. Syntax: find path filespec |
|
find |
-iname |
Find files, ignoring case, by searching all subdirectories. Syntax: find
path -iname filespecfind / -iname "*filespec*" will search the whole disc
for any files with names including the filespec, ignoring
case. |
find |
-name |
Find files by searching all subdirectories. Syntax: find path
-name filespec |
find |
-prune |
Find files but not directories. Syntax: find path -prune
-name filespec |
free |
Displays your memory usage. | |
grep |
-i |
Search for a textstring in a file, case unsensitive. Syntax: grep
-i searchstring filespec |
grep |
-l |
Search for a textstring in a file, only showing filenames. Syntax: grep
-l searchstring filespec |
head |
filename |
display first ten lines of file. Syntax: head file |
kill |
-1 |
Restart a process. Syntax: kill -1 processid |
kill |
-9 |
Brutaly kill a process. Syntax: kill -9 processid |
kill |
-15 |
Stop a process. Syntax: kill -15 processid |
less |
Show the content of a file | |
ls |
List files | |
ls |
-a |
Lists all files, including hidden files |
ls |
-l |
Lists all files using a long format |
mkdir |
Make a directory | |
mv |
Move files. Syntax: mv filename destination |
|
ps |
Show active processes | |
ps |
-a |
Show all users active processes |
ps |
-u |
Show owner and starttime for the active processes |
| ps | -au | show all users' active processes and owners of processes |
pwd |
Show the name and path to the current directory | |
rm |
Remove files | |
rm |
-f |
Remove files without asking first |
rm |
-r |
Remove files, including files in subdirectories |
rmdir |
Remove an empty directory | |
rmdir |
-p |
Remove an empty directory, including empty subdirectories |
su |
Switch user. Syntax: su user. Just su
will ask for the root password |
|
su |
- |
Switch to root and get roots environment and paths |
tail |
filename |
Displays the 10 last lines in a file Syntax: tail file
|
talk |
Chat with another user. Syntax: talk user.
|
|
top |
Continuously displays your processes, CPU usage and memory usage. | |
| uptime | Tells how long linux has been running | |
whatis |
Tells what a program really does. Syntax: whatis program.
Run makewhatis as root to creat database. |
|
whereis |
Searches for a file. Syntax: whereis filename |
Misc. Floppy Disk commands:
| To mount in DOS mode | mount -t msdos /dev/fd0 /mnt/floppy |
| To copy to hard drive | cp /mnt/floppy/FILENAME /PATH/FILENAME |
| To unmount floppy drive | umount /mnt/floppy |
How to manage user acounts
useradd username -d <home_dir>
passwd username
userdel username
How to mount a Windows share point:
mkdir /mnt/mountpoint
smbmount //server/share /mnt/mountpoint -o username=username
Where:
server = The server's name
share = share point
mountpoint = mount point
username = username with access to the share
From here, you can treat it like any other Linux drive.
To un-mount the above, execute the following command: umount /mnt/mountpoint
Make sure you are not on the mount point when you unmount. Otherwise you will get the following error:
Device or resource busy
Message of the day:
This is a text file that is located in /etc/motd. This will be displayed every time someone logs in.
Command line recall: HISTORY
| Run Command Number | !n (where n=number in history list) |
| Run Previous Command | !! |
| Run Command Containing String | !?string? |
It is possible to concatenate multiple commands on one line to be run in a sequential order. To do so, seperate each command with a semi-colon (;). For example: date ; troff -me a_big_document | lpr ; date
To execute a command in the background, end the command with an ampersand (&). for example: troff -me a_big_document | lpr &
to bring a background task to the foreground, use the fg command. For
example: fg %xxx where xxx is the process ID. This can be obtained by
using the ps command. For example: ps -au returns something like:
| USER | PID | %CPU | %MEM | VSZ | RSS | TTY | STAT | START | TIME | COMMAND |
| thompsom | 7819 | 0.3 | 0.5 | 4036 | 1368 | pts/0 |
S
|
16:02 | 0:00 | -bash |
| root | 7849 | 0.1 | 0.3 | 3748 | 964 | pts/0 |
S
|
16:02 | 0:00 | su |
| root | 7850 | 0.7 | 0.5 | 4088 | 1444 | pts/0 |
S
|
16:02 | 0:00 | bash |
| root | 7853 | 0.0 | 0.2 | 2468 | 640 | pts/0 |
R
|
16:02 | 0:00 | ps -au |
From this you get the PID for the process.
If a command is stopped it can be started in the background with the following command: bg %xxx where xxx is the PID from above.
When a background task is done, it will display an exit message the next time the Enter key is pressed.