@@ -11,6 +11,12 @@ The shell, or the terminal is a really useful tool. Bash is the standard shell o
One really useful trick when working with bash is to search for old commands that you have used. You can access this search function by doing `ctr-r` in the terminal.
The configuration file for the bash shell is `~./bashrc`
### Navigating
`pwd` - Print working directory
@@ -113,6 +119,30 @@ which bash
# Usually outputs: /bin/bash
```
#### Creating custom bash functions
If you want to create a new command from other commands, and be able to invoke that command from your terminal, there are a few different way of doing that.
One way is write a bash-script, and then move that script to one of your folders in your $PATH variable.
The other way is to simply write a function in your .bashrc file. You can then invoke that function from anywhere in your terminal.
So for example, if you want to ssh into a machine, but you are tired of having to write the whole command, you can just add this function in your .basrhrc file:
```
function connecttossh {
ssh user@192.168.1.111
}
```
Then you need to source the file, so that it becomes updated: `source ./.bashrc`
Now you can just write connecttossh
## 2. Editing text
First let's just clear out something about **standard streams**, or **I/O**-streams. Standard streams are the streams that are used to interact between the human computer-user and the machine. There are three standard streams: standard input \(stdin\), standard output \(stdout\), and standard error \(stderr\).The stdin stream can be seen as an abstractions of the real keyboard input. So when you issue a command/program that requires input the program does not read straight from the keyboard input, instead it reads from the file STDIN.
