Add some Linux and .NET commands

src/SUMMARY.md

@@ -8,6 +8,7 @@
 - [Linux Commands](./linux.md)
 	- [nginx](./nginx.md)
 	- [Raspberry Pi Commands](./pi.md)
+	- [Directories](./linux/directories.md)
 - [macOS Commands](./macos.md)
 - [T-SQL](./tsql.md)
 - [PostgreSQL](./postgresql.md)

src/dotnet.md

@@ -2,6 +2,7 @@
 
 - [dotnet new](https://docs.microsoft.com/en-us/dotnet/core/tools/dotnet-new)
 	- `dotnet new list`
+	- `dotnet new gitignore` adds a .gitignore to the current directory.
 
 ```powershell
 # View .NET installed versions and information.

src/linux.md

@@ -16,6 +16,12 @@ whoami
 
 # View last hour of SSH logs.
 sudo journalctl -u ssh --since "1 hour ago"
+
+# Determine shell being used.
+ps -p "$$"
+
+# Find process having a process id (PID).
+ps -p <pid>
 ```
 
 ## System management
@@ -180,6 +186,12 @@ ip a
 
 # Server uptime.
 uptime
+
+# View path variable.
+echo $PATH
+
+# Find path of binary.
+which cd
 ```
 
 ## Package management

src/linux/directories.md

@@ -0,0 +1,22 @@
+# Linux Directories
+
+From root (`cd /`):
+
+- `/bin` essential executables, always available
+- `/sbin` essential super user executables
+- `/lib` shared common libraries (for `bin` and `sbin`)
+- `/etc` (editable text configuration)
+- `/usr`
+	- `/usr/local`
+		- `/usr/local/bin` locally compiled binaries
+	- `/usr/bin` installed binaries for users
+- `/home` user data
+	- `/home/___` individual user directory (also `~`)
+- `/boot` required to boot the system (like Linux kernel)
+- `/dev` devices/hardware/drivers
+- `/opt` optional/add-on software, rarely will be used
+- `/var` variable files that change as the system is used (like log and cache files)
+- `/tmp` temporary files
+- `/proc` running processes
+
+Detailed in the [Filesystem Hierarchy Standard](https://refspecs.linuxfoundation.org/FHS_3.0/fhs/index.html).