=====I/O Redirection=====
====Definition====
There is no clear definition for **I/O redirection** but both of these in the UNIX universe in particular are actually two components of our interface that we use at every given moment while actively using the terminal or even this browser. The **Input** is coming from your computer's keyboard or terminal keyboard while the **Output** is what you see on the monitor typically, such as in the Lab46 Terminal, the text you see is the output. In the middle of both input and output is actually where all the processing happens, this is key to the redirection as it has an effect to where the output will be directed.
There are two kinds of I/O redirection, them being represented by the less than and greater than symbols ><. The less than **<** symbol is what does input redirection, commonly useful for when a program doesn't read files but reads from standard input, for example, you can have file1 send its contents to a mail of some sort like jackrabbit@rabies.org and the command would look something like this:
** mail jackrabbit@rabies.org < file1**
The greater than **>** symbol does the "opposite" and is used in a different scenario. Say you wanted all the output you receive from issueing an **ls -l** command to be put into file2. Just do **ls > file2** and all that output will be within the file.
Some other important concepts about I/O redirection is usage of the **pipe |** and the **semicolon ;**. The pipe and semi are used when you want to use more than one command at one time, but the difference between the two is crucial to a successful incantation. The pipe **will** redirect output from the initial command into the next command while the semicolon **will not** redirect any output into the next command, it will just perform it as if you were doing it singularly. A situation where the semicolon is crucial is if you have a **cat** command following your initial casting.
Now when you use the output redirect, one thing to keep in mind is that if you send another piece of output into file2 with a single >, it will overwrite the file with that new output and the old output from ls -l will no longer be there.
====References====
* O'Reilly Learning The UNIX Operating System
=====unix Keyword 2 Phase 2=====
processes
====Definition====
Processes- programs or instances that operate concurrently with one another to produce a result.
====References====
List any sites, books, or sources utilized when researching information on this topic. (Remove any filler text).
* Reference 1: http://en.wikipedia.org/wiki/Process_%28computing%29
* Reference 2: http://www.thefreedictionary.com/Processes
* Reference 3: http://www.merriam-webster.com/dictionary/process
====Demonstration====
Demonstration of the indicated keyword.
If you wish to aid your definition with a code sample, you can do so by using a wiki **code** block, an example follows:
/*
* Sample code block
*/
#include
int main()
{
return(0);
}
Alternatively (or additionally), if you want to demonstrate something on the command-line, you can do so as follows:
lab46:~$ cd src
lab46:~/src$ gcc -o hello hello.c
lab46:~/src$ ./hello
Hello, World!
lab46:~/src$