#### Type Standard
1. Standard Input 0 ( STDIN )
2. Standard Output 1 ( STDOUT )
3. Standard Error 2 ( STDERR )
* Redirecting to an Existing File
> In Case Redirect Output , U Can Using `>` Operator To Store Or Redirect Output In File
```bash
kali@kali:~$ echo "that is maintained and funded by Offensive Security" >>
redirection_test.txt
kali@kali:~$ cat redirection_test.txt
Kali Linux is an open source project
that is maintained and funded by Offensive Security
```
* **Redirecting from a File**
```sh
root@root:~$ wc -m < php.php
89
```
* Redirecting to a New File
```markdown
kali@kali:~$ ls
Desktop Documents Downloads Music Pictures Public Templates Videos
kali@kali:~$ echo "test"
test
kali@kali:~$ echo "test" > redirection_test.txt
kali@kali:~$ ls
Desktop Documents Downloads Music Pictures Public redirection_test.txt Template
kali@kali:~$ cat redirection_test.txt
test
kali@kali:~$ echo "Kali Linux is an open source project" > redirection_test.txt
kali@kali:~$ cat redirection_test.txt
Kali Linux is an open source project
```
> In Case Insert In File Not Use Override In Case Using Just `>` U Can Use `>>` To Insert In File , And Save The Old Value
* Redirecting STDERR
```sh
kali@kali:~$ ls .
Desktop Documents Downloads Music Pictures Public redirection_test.txt Template
kali@kali:~$ ls ./test
ls: cannot access '/test': No such file or directory
kali@kali:~$ ls ./test 2>error.txt
```
> in Case Passing STRDINT Standard Input Using `<`
## 2.Piping
> Return Result From **1st Function** Or Output ***And Passing As A Value To 2nd Tool Or Function***
> `tee` Command Using To Show Result And Store In File , U Can Append In File Because IF U Use Normal Use Delete Old Data, U Can Use Switch `-a` To Append `ls | tee -a`
> And U Can Using Other `xargs` To Control Result And Execute Same Actions
{% hint style="info" %}
In Case Show Errors In Kali U Can Show Result And Comments In The Kali website Bugs And Search From Your Errors [https://bugs.kali.org](https://bugs.kali.org/)
\
Kali Linux adheres to the [filesystem hierarchy standard (FHS)](https://wiki.linuxfoundation.org/lsb/fhs) Which provides a familiar and universal layout for all Linux users
{% endhint %}
