Add new page for PostgreSQL

src/SUMMARY.md

@@ -9,5 +9,6 @@
 	- [Raspberry Pi Commands](./pi.md)
 - [macOS Commands](./macos.md)
 - [T-SQL](./tsql.md)
+- [PostgreSQL](./postgresql.md)
 - [Angular](./angular.md)
 - [Windows Terminal](./windows-terminal.md)

src/linux.md

@@ -16,7 +16,7 @@ whoami
 
 ## System management
 ```bash
-# Reboot
+# Reboot/restart.
 sudo reboot
 sudo shutdown -r now
 # Reboot in 5 minutes.

src/node/globals.md

@@ -3,6 +3,7 @@ The following is a list of globals I tend to install with Node. Items are listed
 
 ```
 npm install ___ -g
+npm install -g ___
 ```
 
 Again, you can run `npm ls -g --depth 0` to view any packages that have been installed globally.

src/postgresql.md

@@ -0,0 +1,28 @@
+# PostgreSQL
+Unless otherwise noted, non-SQL commands are running under Ubuntu.
+
+```bash
+# List all databases.
+sudo -u postgres psql -l
+```
+
+## Configuration
+
+```bash
+# Show the full path to the PostgreSQL configuration file.
+sudo -u postgres psql -c 'SHOW config_file'
+# Example: /etc/postgresql/12/main/postgresql.conf
+
+# Show the full path to the HBA configuration file.
+sudo -u postgres psql -c 'SHOW hba_file'
+# Example: /etc/postgresql/12/main/pg_hba.conf
+```
+
+```sql
+-- Locate the HBA configuration file.
+SHOW hba_file;
+-- Example: /etc/postgresql/12/main/pg_hba.conf
+
+-- Or just query the file for rules.
+select * from pg_hba_file_rules();
+```