AZ-104 Notes

Cloud/Azure/AZ-104--Administrator/ms-learn/README.md

@@ -11,3 +11,4 @@
 * [Use Azure Resource Manager](./prerequisites-for-azure-admin--01-use-azure-resource-manager.md)
 * [Introduction to Azure Cloud Shell](./prerequisites-for-azure-admin--02-intro-to-azure-cloud-shell.md)
 * [Introduction to Bash](./prerequisites-for-azure-admin--03-intro-to-bash.md)
+* [Introduction to PowerShell](./prerequisites-for-azure-admin--04-intro-to-powershell.md)

Cloud/Azure/AZ-104--Administrator/ms-learn/prerequisites-for-azure-admin--03-intro-to-bash.md

@@ -41,3 +41,83 @@ Wildcards are symbols that represent one or more characters in Bash commands. Th
 ```bash
 ls *.png
 ```
+
+### Bash Commands and Operators
+
+#### `ls [-a] [-l]` command
+
+`ls` lists the contents of your current directory or the directory specified in an argument to the command. By itself, it lists the files and directories in the current directory.
+
+#### `cat` command
+
+`cat` shows the contents of a file.
+
+```bash
+cat /etc/os-release
+```
+
+This is a useful command because it tells you which Linux distribution you're running:
+
+```bash
+NAME="Ubuntu"
+VERSION="18.04.2 LTS (Bionic Beaver)"
+ID=ubuntu
+ID_LIKE=debian
+PRETTY_NAME="Ubuntu 18.04.2 LTS"
+VERSION_ID="18.04"
+HOME_URL="https://www.ubuntu.com/"
+SUPPORT_URL="https://help.ubuntu.com/"
+BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
+PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
+VERSION_CODENAME=bionic
+UBUNTU_CODENAME=bionic
+```
+
+#### `sudo` command
+
+Some Bash commands can only be run by the root user; a system administrator or superuser. If you try one of these commands without sufficient privileges, it fails.
+
+You don't want to run as root most of the time; it's too dangerous. To run commands that require admin privilege without logging in as a superuser, you'll preface the commands with `sudo`.
+
+`sudo` stands for "superuser do." When you use it, you're telling the shell that for this one command, you're acting with the root-user level of permission.
+
+#### `cd`, `mkdir`, and `rmdir` commands
+
+`cd` stands for "change directory," and it does exactly what the name suggests: it changes the current directory to another directory. It enables you to move from one directory to another just like its counterpart in Windows.
+
+You can create directories by using the `mkdir` command.
+
+The `rmdir` command deletes (removes) a directory, but only if it's empty. If it's not empty, you'll get a warning instead.
+
+#### `rm [-r]` command
+The `rm` command is short for "remove." As you'd expect, `rm` deletes files.
+
+#### `cp [-r] [-i]` command
+The `cp` command copies not just files, but entire directories (and subdirectories) if you want.
+
+#### `ps [-ef]` command
+
+The ps command gives you a snapshot of all the currently running processes. By itself, with no arguments, it shows all your shell processes; in other words, not much.
+
+`-e` lists all running processes, and there are typically many of them.
+
+For a more comprehensive look at what processes are running in the system, use the `-ef` flag.
+
+#### `w` command
+
+Users come, users go, and sometimes you get users you don't want at all. Sysadmins are also expected to know who's logged in, and who shouldn't be.
+
+To find out who's on your servers, Linux provides the `w` (for "who") command. It displays information about the users currently on the computer system and those users' activities. `w` shows user names, their IP addresses, when they logged in, what processes they're currently running, and how much time those processes are consuming. It's a valuable tool for sysadmins.
+
+#### `pwd` command
+
+`pwd` stands for "print working directory."
+
+### Bash I/O operators
+
+You can do a lot in Linux just by exercising Bash commands and their many options. But you can really get work done when you combine commands by using I/O operators:
+
+* `<` for redirecting input to a source other than the keyboard.
+* `>` for redirecting output to destination other than the screen.
+* `>>` for doing the same, but appending rather than overwriting.
+* `|` for piping output from one command to the input of another.

Cloud/Azure/AZ-104--Administrator/ms-learn/prerequisites-for-azure-admin--04-intro-to-powershell.md

@@ -0,0 +1,2 @@
+# Introduction to PowerShell
+