Fix bash scripts

chapter1/coprocess.sh

@@ -0,0 +1,64 @@
+#!/usr/bin/env bash
+#
+# SCRIPT: coprocess.sh
+# AUTHOR: Fabio Scotto di Santolo
+# DATE:   29/07/2020
+# REV:    1.1.A 
+#
+# PLATFORM: Not platform dependent
+#
+# PURPOSE: 
+#
+# REV LIST: 
+#
+##########################################################
+#              DEFINE FUNCTIONS HERE
+##########################################################
+ 
+function trap_exit
+{
+    # Tell the co-process to break out of the loop
+    break_out='Y'
+    print -p $break_out # Use "print -p" to talk to the co-process
+}
+
+function proc_watch
+{
+    # This function is started as a co-process
+    while :     # Loop forever
+    do
+        read $break_out     # Do NOT need "-p" to read!
+        if [[ $break_out == 'Y' ]];
+        then
+            return 0
+        fi
+    done
+}
+
+##########################################################
+#               BEGINNING OF MAIN
+##########################################################
+
+trap 'trap_exit; exit 2' 1 2 3 15
+
+total_seconds=300
+break_out='N'
+
+coproc proc_watch   # Start proc_watch as a co-process!!!
+pw_pid=$1           # Process ID of the last background job
+
+until [ total_seconds -eq 0 ];
+do
+    (( total_seconds=total_seconds - 1 ))
+    sleep 1
+done
+
+break_out='Y'
+
+# Use "print -p" to communicate with the co-process variable
+print -p $break_out
+
+kill $pw_pid        # Kill the background co-process
+exit 0
+
+# End of script