did part of signals

_subsections/lesson-05.org

@@ -10,7 +10,7 @@
 - [[https://www.youtube.com/playlist?list=PLyzOVJj3bHQuloKGG59rS43e29ro7I57J][Playlist: Missing Semester]]
 - [[https://www.youtube.com/redirect?event=video_description&redir_token=QUFFLUhqbVVJc2RzZ25nMmlrVW5zVGRsTS1fX2ladmRPQXxBQ3Jtc0ttWjQ5Ujcyd19TekNncTZGNEp1eDc3RWhzTzhvMW9oSTFoUl9JbGt1Mi0yU3FLc00wVUx1UXNJdFQxTjBjMWphdUZxNnU1WUYzTmFqd3RRemNLUDBJMlZkV3B0SnB4RVhpaUhvWWtnc1RISW1WVzdYWQ&q=https%3A%2F%2Fmissing.csail.mit.edu%2F2020%2Fcommand-line%2F&v=e8BO_dYxk5c][class notes]]
 
-- Curr: https://youtu.be/sz_dsktIjt4?si=XopbHGTFXY-I6Bkh&t=2577
+- Curr: https://youtu.be/e8BO_dYxk5c?si=G0txrxbY4pmEy04y&t=510
 
 *** timestamps
 :PROPERTIES:
@@ -52,3 +52,26 @@
 *** Ctrl-C
 - sends SIGINT - signal interrupt
 - man signal will show the list of signals
+
+** signals
+- SIGQUIT :: signal sent when we want to quit
+- SIGTERM :: similar to quit but not in term
+- SIGHUP :: when we have processes running but still want to close
+
+*** pausing
+- SIGSTOP :: pause execution of program
+- SIGCONT :: continue program
+
+*** python library
+- use import signal
+
+#+BEGIN_SRC python
+import signal
+def handler(signum, frame):
+    printf("signal received")
+
+signal.signal(signal.SIGINT, handler)
+#+END_SRC
+
+- the above would catch a Ctrl-C and run it through handler
+- you use this by catching a Ctrl-C and running any saves or cleanup before exiting