AIX create you own demon (daemon)

Create fksubsys service:

mkssys -p /path/to/fkcmd \ # Absolute path to subsystem bin or script
        -a "arg1 arg2" \     # if Arguments to the command
        -s fksubsys \        # Unique name for the subsystem (-t fkalias)
        -G fkgrp \           # Subsys group
        -u 202 \             # User id for the subsystem (0 for root)
        -i /dev/console \    # Stdin got from (default)
        -o /dev/console \    # Stdout sent to (default)
        -e /dev/console \    # Stderr sent to (default)
        -R \                 # Restart subsys if halted abnormally (or -O)
        -Q \                 # One instance only # -q if multiple instances 
        -S \                 # Subsys supports signals 
         \                   # or -I msgqueue -m msgtype (or -K if sockets)
        -f 9 \               # signal KILL for forced stopsrc -f
        -n 15 \              # signal TERM for normal stopsrc
        -w 10 \              # 10 seconds between a TERM and KILL & restart)
        -E 24 \              # Subsys priority (20 default)
        -d                   # lssrc -a lists subsys even if inactive else -D

lssrc -S -s fksubsys # Check the service's configuration: OR... 
odmget -q subsysname=fksubsys SRCsubsys # ... via the odm.

startsrc -s fksubsys  # startsrc -g fkgrp  # two ways to launch it
stopsrc -s fksubsys # and to stop it

mkitab -i cron fkcmd:2:respawn:startsrc -s fksubsys # start subsys via /etc/inittab

Change the subsystem:

chssys -s old_subsystem_name
        {[-s new_subsystem_name]
        [-t synonym_name]
        [-a command_arguments]
        [-p subsystem_path]
        [-u userid]
        [-i stdin]
        [-o stdout]
        [-e stderr]
        [-R | -O]
        [-d | -D]
        [-q | -Q]
        [{-I message_queue_key -m subsystem_mtype}
                | {-S -n signorm -f sigforce} | -K]
        [-E priority]
        [-G group_name]
        [-w wait_time] }

# startsrc -s lpd -a "-D /tmp/lpd.debug"

Example of demon, for printer demon

[root@nim]/root# odmget -q subsysname=lpd SRCsubsys

SRCsubsys:
        subsysname = "lpd"
        synonym = ""
        cmdargs = ""
        path = "/usr/sbin/lpd"
        uid = 0
        auditid = 0
        standin = "/dev/console"
        standout = "/dev/console"
        standerr = "/dev/console"
        action = 1
        multi = 0
        contact = 3
        svrkey = 0
        svrmtype = 0
        priority = 20
        signorm = 0
        sigforce = 0
        display = 1
        waittime = 20
        grpname = "spooler"

Redirect errors and standard output to /dev/null

[root@nim]/root# chssys -s lpd -e "/dev/null"  -o "/dev/null"

0513-077 Subsystem has been changed.
[root@nim]/root# odmget -q subsysname=lpd SRCsubsys

SRCsubsys:
        subsysname = "lpd"
        synonym = ""
        cmdargs = ""
        path = "/usr/sbin/lpd"
        uid = 0
        auditid = 0
        standin = "/dev/console"
        standout = "/dev/null"
        standerr = "/dev/null"
        action = 1
        multi = 0
        contact = 3
        svrkey = 0
        svrmtype = 0
        priority = 20
        signorm = 0
        sigforce = 0
        display = 1
        waittime = 20
        grpname = "spooler"

Then restart the demon (you can sometimes use refresh -s lpd)

[root@nim]/root# stopsrc -s lpd ; startsrc -s lpd

To remove a subsystem, use

# rmssys -s Subsystem