adds missing python scripts

advanced/learning_processes.md

@@ -405,6 +405,6 @@ TODO
 To help you understand what happens to running and stopped processes I made a few python scripts you can download below.
 Run them either with `python3 $SCRIPT_NAME` or `./$SCRIPT_NAME`.
 
-* [simple timer](./assets/processes_ex_01.py)
+* [simple timer](../assets/processes_ex_01.py)
-* [timer with random keyboard prompt](./assets/processes_ex_02.py)
+* [timer with random keyboard prompt](../assets/processes_ex_02.py)
-* [custom callback function for SIGALRM](./assets/processes_ex_03.py)
+* [custom callback function for SIGALRM](../assets/processes_ex_03.py)

assets/processes_ex_01.py

@@ -0,0 +1,13 @@
+import time
+import os
+
+start_ts = time.time()
+loops = 0
+
+while True:
+    time.sleep(1)
+    loops += 1
+    tick_ts = time.time()
+    delta = int(tick_ts - start_ts)
+    pid = os.getpid()
+    print("I'm {} and I've been running for {} seconds and did {} loops".format(pid, delta, loops))

assets/processes_ex_02.py

@@ -0,0 +1,23 @@
+import time
+import os
+import random
+
+start_ts = time.time()
+loops = 0
+
+while True:
+    time.sleep(1)
+    loops += 1
+    tick_ts = time.time()
+    delta = int(tick_ts - start_ts)
+    pid = os.getpid()
+    print("I'm {} and I've been running for {} seconds and did {} loops".format(pid, delta, loops))
+    chance = random.randint(0, 20)
+    if chance == 5:
+        response = input("I need some input...")
+        if len(response) == 0:
+            exit(0)
+        else:
+            print("thanks for the response, I'll reset my counter and continue now...")
+            start_ts = time.time()
+            loops = 0

assets/processes_ex_03.py

@@ -0,0 +1,18 @@
+import time
+import os
+import signal
+
+def alarm_handler(signum, frame):
+    print("I'm an alarm hear me ring! (my ID is {})".format(signum))
+
+def main():
+    print("I'm {}".format(os.getpid()))
+    while True:
+        time.sleep(1)
+
+if __name__ == "__main__":
+    signal.signal(signal.SIGALRM, alarm_handler)
+    try:
+        main()
+    except Exception as e:
+        print(e)