On: SpoofMAC - Spoof your MAC address in Mac OS X

[nikcub]

should redirect the error/warning output so that it isn't mashed into the command:

    openssl rand -hex 6 2>/dev/null | sed 's/\(..\)/\1:/g; s/.$//'

because if you are running this on startup there is a chance HOME or RANDFILE aren't set yet, the .rnd file doesn't exist or the permissions on it are not set properly - resulting in a warning such as "PRNG not seeded" or "unable to write 'random state'" that would be passed into the ifconfig command.

[decklin → nikcub]

Command substitution does not capture standard error.

[nikcub → decklin]

you're right, it is from my own script where I do it different with more sanity checks and my own errors, I just applied it to the line above.

I'm also in that habit for anything fired at startup or in cron so you don't pollute logs.