Process Watcher

A method for installed playback systems. Set as a login item for macOS. Adjust the variables as necessary. The watcher script will check that the defined process exists. If not, it will relaunch the target file. Based on the work of Jim Bell for Generativity by Fernanda D’Agostino, Suyama Space, Seattle WA, 2016. Refined and expanded since then.

#!/bin/bash
#
# ----------------------------------------------------------------------------
# FILE: processWatcher_TEMPLATE.sh
# AUTHOR: Brendan Hogan | Kreiva Laboratories
# DATE: 2023-01-26
#
# DESCRIPTION
# Monitor for a defined process(es) in macOS to ensure that the process or 
# processes are valid. If a non-zero reply to the query is returned, the script 
# will re-launch the defined process or processes.
# This script is intended for installation media compositions where continuous
# or scheduled operation is required. 
# 
# INSTRUCTIONS
# Define your first process name as 'firstProcess' and first file name as
# 'firstFile'. Define your second process name/file (if applicable) in a
# similar manner. Use Activity Monitor to identify process names.
#
# NOTE: File pathways with spaces are enclosed in single quotes. /usr/bin/open 
# commands where the file name contains spaces are enclosed in double quotes.
# Add additional processes/files as required. Make the script executable, with 
# Terminal as the default application. Set the shell file as a Login Item.
# ----------------------------------------------------------------------------
#
# VARIABLES
FIRSTPROCESS=someProcess
FIRSTFILE=/path/to/file/noSpaces.extension
SECONDPROCESS=someOtherProcess
SECONDFILE='/path/to/file/with spaces.extension'
#MAKEFRONT=/Users/USERNAME/Desktop/makeFront.app # use to bring an app to front
LAUNCHSLEEP=30 # sleep time in seconds
#FRONTSLEEP=10 # use to sleep the launch time of makeFront
LOOPSLEEP=10 # sleep time between checks
#
# Set Terminal window to 40 x 80
printf '\e[8;40;80t'
clear
# MAIN RUNNER
# Print info to Terminal
echo "------------------------------------------------------------------------"
echo " Monitor $FIRSTPROCESS and $SECONDPROCESS and run watcher loops.        "
echo " Restart $FIRSTPROCESS and/or $SECONDPROCESS if they crash.             "
echo " Waiting for 10 seconds.                                                "
echo " -----------------------------------------------------------------------"
sleep 10
# LAUNCH APPLICATION(S):
/usr/bin/open $FIRSTFILE
sleep $LAUNCHSLEEP
/usr/bin/open $SECONDFILE
#sleep $FRONTSLEEP
#/usr/bin/open $MAKEFRONT
#
# RUN PRIMARY LOOP
echo " Starting $FIRSTPROCESS watcher loop. "
until [ 0 = 1 ]
do
     /usr/bin/killall -0 $FIRSTPROCESS
    if [ $? = 0 ]												
    then
    echo "$FIRSTPROCESS is active. Checking again in $LOOPSLEEP seconds..."
    else
    echo ""
	echo "" 
	echo "$(date): Error: Process not found - restarting $FIRSTPROCESS"
	echo ""
	echo ""								
    /usr/bin/open $FIRSTFILE
    fi
    sleep $LOOPSLEEP								
done &
# RUN SECONDARY LOOP
echo " Starting $SECONDPROCESS watcher loop. "
until [ 0 = 1 ]
do
     /usr/bin/killall -0 $SECONDPROCESS
    if [ $? = 0 ]													
    then
    echo "$SECONDPROCESS is active. Checking again in $LOOPSLEEP seconds..."
    else
    echo ""
	echo "" 
	echo "$(date): Error: Process not found - restarting $SECONDPROCES"
	echo ""
	echo ""								
    /usr/bin/open "$SECONDFILE"
    fi
    sleep $LOOPSLEEP								
done

#!/bin/bash

# ----------------------------------------------------------------------------

# FILE: processWatcher_TEMPLATE.sh

# AUTHOR: Brendan Hogan | Kreiva Laboratories

# DATE: 2023-01-26

# DESCRIPTION

# Monitor for a defined process(es) in macOS to ensure that the process or

# processes are valid. If a non-zero reply to the query is returned, the script

# will re-launch the defined process or processes.

# This script is intended for installation media compositions where continuous

# or scheduled operation is required.

# INSTRUCTIONS

# Define your first process name as 'firstProcess' and first file name as

# 'firstFile'. Define your second process name/file (if applicable) in a

# similar manner. Use Activity Monitor to identify process names.

# NOTE: File pathways with spaces are enclosed in single quotes. /usr/bin/open

# commands where the file name contains spaces are enclosed in double quotes.

# Add additional processes/files as required. Make the script executable, with

# Terminal as the default application. Set the shell file as a Login Item.

# ----------------------------------------------------------------------------

# VARIABLES

FIRSTPROCESS=someProcess

FIRSTFILE=/path/to/file/noSpaces.extension

SECONDPROCESS=someOtherProcess

SECONDFILE='/path/to/file/with spaces.extension'

#MAKEFRONT=/Users/USERNAME/Desktop/makeFront.app # use to bring an app to front

LAUNCHSLEEP=30 # sleep time in seconds

#FRONTSLEEP=10 # use to sleep the launch time of makeFront

LOOPSLEEP=10 # sleep time between checks

# Set Terminal window to 40 x 80

printf '\e[8;40;80t'

clear

# MAIN RUNNER

# Print info to Terminal

echo "------------------------------------------------------------------------"

echo " Monitor $FIRSTPROCESS and $SECONDPROCESS and run watcher loops. "

echo " Restart $FIRSTPROCESS and/or $SECONDPROCESS if they crash. "

echo " Waiting for 10 seconds. "

echo " -----------------------------------------------------------------------"

sleep 10

# LAUNCH APPLICATION(S):

/usr/bin/open $FIRSTFILE

sleep $LAUNCHSLEEP

/usr/bin/open $SECONDFILE

#sleep $FRONTSLEEP

#/usr/bin/open $MAKEFRONT

# RUN PRIMARY LOOP

echo " Starting $FIRSTPROCESS watcher loop. "

until [ 0 = 1 ]

/usr/bin/killall -0 $FIRSTPROCESS

if [ $? = 0 ]

then

echo "$FIRSTPROCESS is active. Checking again in $LOOPSLEEP seconds..."

else

echo ""

echo "$(date): Error: Process not found - restarting $FIRSTPROCESS"

echo ""

/usr/bin/open $FIRSTFILE

sleep $LOOPSLEEP

done &

# RUN SECONDARY LOOP

echo " Starting $SECONDPROCESS watcher loop. "

until [ 0 = 1 ]

/usr/bin/killall -0 $SECONDPROCESS

if [ $? = 0 ]

then

echo "$SECONDPROCESS is active. Checking again in $LOOPSLEEP seconds..."

else

echo ""

echo "$(date): Error: Process not found - restarting $SECONDPROCES"

echo ""

/usr/bin/open "$SECONDFILE"

sleep $LOOPSLEEP

done

Stopping the process watcher loop (AppleScript):

-- processWatcher_Killer.scpt
-- Author: Brendan Hogan
-- Version: 1.2
-- Date: 2023-01-01

-- A script to emulate a SUSPEND command ('Ctrl-Z') in the Terminal, then kill the process watcher shell script.
– Adjust myApplication variable(s) to quit the watched applications defined in the processWatcher shell loop.
– Quit Terminal at end.


set firstApplication to “enter name of FIRSTPROCESS above”
set secondApplication to “enter name of SECONDPROCESS above”
tell application "Terminal"
	activate
end tell
delay 5
tell application "System Events" -- script user interface behavior
	keystroke "z" using {control down} -- send the Unix SUSPEND command "Ctrl+Z"
	delay 1
	keystroke "kill %%"
	keystroke return
end tell
delay 10
try
	tell application firstApplication
		quit
	end tell
end try
delay 5
tell application secondApplication
quit
repeat until application secondApplication is not running – use this to prevent hangs of slow-responding applications. Comment out if unnecessary.
	delay 1
end repeat
delay 5
tell application "Terminal" to quit