Here’s another logging routine, this one is written in Bourne shell:

#!/bin/sh

log_message() {
    echo `date "+%m/%d/%y %H:%M:%S %Z"` "$1" | tee -a aaa.out
}

log_message "Hello there"
log_message "Goodbye"

Sample output:

08/28/07 23:16:13 EDT Hello there
08/28/07 23:16:13 EDT Goodbye

 

Here’s how to find out your external IP address courtesy of this hint:

http://www.macosxhints.com/article.php?story=20060602180942480

curl --silent http://checkip.dyndns.org
    | awk '{print $6}' | cut -f 1 -d "<"

If you are using Apple’s Airport Extreme Basestation (mine is particularly the Time Capsule and this is where I have tested this), and you have the SNMP interface enabled, you can run the following command

prompt$ snmpwalk -Os -c public -v 1 192.168.63.1 ipAdEntAddr IpAddress 
    | grep -E -v '(127.0.0|169.254|192.168.63.1)' 
    | cut -d : -f 2 | sed 's/ //g'

Line terminations for different operating systems:

unix	0x0a	LF
Classic Mac	0x0d	CR
Windows	0x0d 0x0a	CR LF

To convert a text file with DOS line termination to UNIX line termination:

tr -d '15'  unixfile.txt

or

sed s/.$// winfile.txt > unixfile.txt

To convert a unix file to a DOS file:

sed s/$/x0d/ unixfile.txt > winfile.txt