A.P. Lawrence

2005/05/15 launchd (Mac OS X Tiger startup)

With Mac OS X Tiger, "launchd" is now pid 1:

$ ps ajxw |sort -n +1| head
USER       PID  PPID  PGID   SESS JOBC STAT  TT       TIME COMMAND
root         1     0     1 166ae88    0 S<s   ??    0:02.76 /sbin/launchd
root        28     1    28 166ac60    0 Ss    ??    0:00.01 /sbin/dynamic_pager -F /private/var/vm/swapfile
root        32     1    32 166ab4c    0 Ss    ??    0:01.79 kextd
root        36     1    36 166aa38    0 Ss    ??    0:06.28 /usr/sbin/configd
root        37     1    37 166a924    0 Ss    ??    0:01.23 /usr/sbin/coreaudiod
root        38     1    38 166a810    0 Ss    ??    0:01.62 /usr/sbin/diskarbitrationd
root        39     1    39 166a6fc    0 Ss    ??    0:00.06 /usr/sbin/memberd -x
root        40     1    40 166a5e8    0 Ss    ??    0:00.95 /usr/sbin/securityd
root        42     1    42 166a4d4    0 Ss    ??    0:01.50 /usr/sbin/notifyd

Quite obviously, it is filling the role that init plays on System V systems. It is also intended to replace rc scripts (from the man page):

NOTES
     In Darwin it is preferable to have your daemon launch via launchd instead
     of modifying rc or creating a SystemStarter Startup Item.

     At some point in the future, we hope to completely phase out the use of
     rc.

It's even taken over some things that used to be done by cron such as running "perodic":

$ cat /etc/crontab
# The periodic and atrun jobs have moved to launchd jobs
# See /System/Library/LaunchDaemons
#

Oddly, you'll find apparent duplication of content in /System/Library/LaunchDaemons and /etc/xinetd.d files.

Comments /Words2005/2005_05_15.html


Fri Jun 10 01:29:26 2005: Subject: Re: launchd (Mac OS X Tiger startup)   anonymous
The duplication between /etc/xinetd.d and /System/Library/LaunchDaemons is probably explained by the method of installing Tiger. If you upgrade, any contents of xinetd.d are preserved, while xinetd.d is empty after a clean Tiger install (including Archive and Install).



Add your comments

Why no "Digg this!" etc.?

Enter your email address for automatic notification of new posts here
(be sure to whitelist 'feedburner.com' if you use spam filtering)

Lone-Tar Backup and Disaster Recovery
for Linux and Unix

Have you tried Searching this site?

Unix/Linux/Mac OS X support by phone, email or on-site: Support Rates

This is a Unix/Linux resource website. It contains technical articles about Unix, Linux and general computing related subjects, opinion, news, help files, how-to's, tutorials and more. We appreciate comments and article submissions.

Publishing your articles here