From 94e19663cdf24535bac8dabf0e843c394bfca94c Mon Sep 17 00:00:00 2001
From: ronny abraham <ronny.abraham@ymail.com>
Date: Mon, 10 Mar 2025 04:43:17 +0200
Subject: [PATCH] started data wranglang

---
 _subsections/lesson-04.org | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/_subsections/lesson-04.org b/_subsections/lesson-04.org
index 218ede6..c00daf3 100644
--- a/_subsections/lesson-04.org
+++ b/_subsections/lesson-04.org
@@ -10,7 +10,7 @@
 - [[https://www.youtube.com/playlist?list=PLyzOVJj3bHQuloKGG59rS43e29ro7I57J][Playlist: Missing Semester]]
 - [[https://missing.csail.mit.edu/2020/data-wrangling/][class notes]]
 
-- Curr: https://youtu.be/sz_dsktIjt4?si=BekzMmns2yPtCWOz
+- Curr: https://youtu.be/sz_dsktIjt4?si=0WESCuewbWY5mJiv&t=622
 
 
 *** timestamps
@@ -24,7 +24,7 @@
 + [[https://www.youtube.com/watch?v=sz_dsktIjt4&t=456s][07:36 - Replacement Expressions]]
 + [[https://www.youtube.com/watch?v=sz_dsktIjt4&t=538s][08:58 - Regular Expression]]
 + [[https://www.youtube.com/watch?v=sz_dsktIjt4&t=560s][09:20 - Regular Expressions]]
-+ [[https://www.youtube.com/watch?v=sz_dsktIjt4&t=620s][10:20 - Square Brackets]]
++ [[https://www.youtube.com/watch?v=sz_dsktIjt4&t=620s][10:20 - Square Brackets]] *current*
 + [[https://www.youtube.com/watch?v=sz_dsktIjt4&t=693s][11:33 - Add Modifiers]]
 + [[https://www.youtube.com/watch?v=sz_dsktIjt4&t=776s][12:56 - Alternations]]
 + [[https://www.youtube.com/watch?v=sz_dsktIjt4&t=1029s][17:09 - Anchoring the Regular Expression]]
@@ -45,4 +45,27 @@
 + [[https://www.youtube.com/watch?v=sz_dsktIjt4&t=2880s][48:00 - display in an image display]]
 
 * notes
+** intro example
+- using ssh someserver 'somecommand' will run that command on the server
+- you could run a series of commands on the server instead of channeling all that info back
 
+  #+BEGIN_SRC bash
+  ssh someserver 'journalctl | grep sshd | grep "Disconnected from"' | less
+  #+END_SRC
+
+- this will run journalctl on the server, find anything that says 'sshd' and 'disconnec..' in the results
+- then send all those results back to our machine where we pipe it through 'less'
+
+** SED
+- stream editor
+- allows you to make changes to the contents of a stream
+- full programming langauge
+- common task is to run replacement expressions on an input stream
+
+*** example
+#+BEGIN_SRc bash
+sed 's/.*blahblah blah//'
+#+END_SRC
+
+- uses regular expressions
+  - way of matching text