Manual linux

|Guide - Basic Commands |
|General | Filesystem | Administrative | Process | Network |
|Linux has so many commands that it's easy for the uninitiated to feel overwhelmed. Don't panic. Linux's commands are all quite simple and easy to learn.|
|As for those commands that appear bewilderingly complex, it's just an illusion. Long, seemingly complicated commands are actually just made up of |
|multiple, simpler commands. They achieve their power by being able to work together. This is the way of the UNIX world in general. |
|Let's look at an example: |
| |
| cat /var/log/messages | grep failed |
|This command will sort through your log file and list all of the failed login attempts since the system was last started. The entire line is actually |
|composed of three small commands: |
|cat prints out the contents of a text file. Here, we are telling it to display the contents of the file /var/log/messages (this is your main log file.) |
|| This symbol is called the pipe (it is located to the left of your backspace key.) It is used to take the output of one command (in this case cat) and |
|pass it to a second (grep, in our example.)