Autosave: 2022-12-11 14:30:05

Operating_Systems/Devices.md

@@ -47,6 +47,6 @@ The [mode](/Programming_Languages/Shell_Scripting/File_permissions_and_execution
 
 ## /dev/null
 
-`/dev/null` is a virtual device: it doesn't actually exist as a piece of hardware on the system.
+`/dev/null` is a virtual device: it doesn't actually exist as a piece of hardware on the system. It can be useful when [bash scripting](/Programming_Languages/Shell/Redirect_to_dev_null.md) as a place to direct output that you don't care about, for example errors or verbose program read-outs.
 
 > ! Make notes on this. Base on : https://linuxhint.com/what_is_dev_null/

Programming_Languages/Shell/Redirect_to_dev_null.md

@@ -0,0 +1,29 @@
+---
+categories:
+  - Programming Languages
+tags:
+  - shell
+---
+
+# Redirecting to `/dev/null`
+
+You'll see the following a lot when reading shell scripts:
+
+```bash
+[some_command] > /dev/null 2>&1
+
+```
+
+This is a redirection statement. It is redirecting data to the `null` device on Unix systems. Basically to a black hole or shredder where you can't access it because you don't want it to be output to stout.
+
+The `2>&1` argument is the content: any errors that the program may generate and try to show in stout.
+
+## Example
+
+I have used this in my Mongo start-up script:
+
+```
+mongodb-compass > /dev/null 2>&1
+```
+
+Here, I just want the MongoDB Compass application to start, I don't care if it wants to output complaints to the stout.