$ wget -q -O - http://ipchicken.com |  grep -o -E '(^|[[:space:]])[0-9]*\.[0-9]*\.[0-9]*\.[0-9]*([[:space:]]|$)'
# By default, FreeBSD doesn't have wget, you can use fetch instead
$ fetch -q -o - http://www.ipchicken.com | grep -o -E '(^|[[:space:]])[0-9]*\.[0-9]*\.[0-9]*\.[0-9]*([[:space:]]|$)'

You need port 80 external/WAN access to perform the task.

For example I am hosting multiple web applications, the development might have several pg_connect command to connect database, in the event I am migrating database to other IP address, it might be hard for them to dig the file and replace the IP Address with new IP Addresses.

In Linux/Unix, you can search through the directories, looking for the files and replace it with the new IP address. Here is the sample.

shell> find /path/to/dir/* -type f -exec sed -i .backup20100714 -e "s/host=x.x.x.x/host=y.y.y.y/g" {} \\;

The command above will search for files in the directory.
find -type f mean look for File only.
find -exec is to execute something from returned results.
sed -i means backup the files, in case you would like to restore later.
sed -e “s/host=x.x.x.x/host=y.y.y.y/g” is to replace x.x.x.x to y.y.y.y

You have backup files name filename.php.backup20100714, now what you need to do is move the files in a backup directory.

shell> find /path/to/dir/* -name "*.backup20100714" -exec mv {} /your/backup/dir/ \\;

You might want to explore on find command, it can do a lot of cool stuffs.

For example I have a file name wireless.pcap, last update or created was in year 2009. I can change the last modify time by the touch command touch -t yyyymmddhhmm filename

shell> touch -t 201007101540 wireless.pcap

This will change the file last updated date and time to 10th July 2010 15:40pm.

In Linux, using “useradd” is pretty common for creating new user access. You can also use “useradd” in FreeBSD, but not directly invoke “useradd” command. Below is the sample of creating new user in FreeBSD with “useradd”.

shell> pw useradd cheryl -c 'Cheryl Windows Admin' -d /home/cheryl -s /usr/local/bin/bash

New user account is created, but don’t forgot to set password for the account

shell> passwd cheryl

You can run other command like “userdel”, “usermod”, “usershow”, “groupadd”, “groupdel”, “groupmod”, “lock”, “unlock” on FreeBSD by using the “pw” command.

Joking aside, how to change server hostname in Unix FreeBSD? There are 2 ways to do it, one is the easy way another is the geeky way. Depend on yourself, if you want to show your elite skills, do it with the text editor, or make the change with Sysinstall.

Change Hostname in Unix FreeBSD with Sysinstall

• In command line, type: sysinstall
• Select Configure
• Select Networking
• Select Interfaces
• Select your Network Interface Card (em0 em1 fxp0)
• No IPV6 (Select yes if you are running on ipv6)
• No DHCP (Select yes if you are running on dhcp)
• host: should be your server name like chelsea
• domain: should be your own domain like takizo.com
• Select Ok
• Exit, Exit, Exit
• In command shell, type: hostname chelsea.takizo.com

This will update your new hostname in Unix FreeBSD box. But please take note you will have extra junk in /etc/rc.conf. So it’s recommend to change your hostname in Unix FreeBSD with following method.

Change Hostname in Unix FreeBSD in “Clean” Way

• In command shell, type: hostname chelsea.takizo.com
• Edit /etc/hosts with vi, change the existing hostname to your new hostname
• Edit /etc/rc.conf with vi, on the “hostname” variable change the existing hostname to your new hostname

This is the better approach in order to organize your /etc/rc.conf clean and clear.

To change user’s shell environment in FreeBSD.

shell> chsh -s /usr/local/bin/bash userid

To change your shell environment in FreeBSD

shell> chsh -s /usr/local/bin/bash

Create a sample file file random name ended with *.sample. Example

touch apple.sample.cfg
touch microsoft.sample.cfg
touch php.sample.cfg
touch config.sample.cfg
touch apache.sample.cfg
touch mysql.sample.cfg
touch pgsql.sample.cfg
touch cacti.sample.cfg
touch wordpress.sample.cfg
touch jessicaalba.sample.cfg

Now you have all the sample configuration, you are going to use them. Are you going to copy one by another and change the same with .cfg prefix? We can do it, in a better and faster way.

Make a new directory to store all the sample file

mkdir sample
cp *.sample.cfg sample/

After that, go to sample directory and copy the files to a location

cd sample 
for d  in `ls *.sample.cfg`; do cp $d `echo $d | sed s/sample.cfg/cfg`; done

That one simple line will easily save you 1-2 minutes.

To enable SSHD on FreeBSD

• Edit the file: vi /etc/rc.conf
• Add: sshd_enable=”YES”
• To start sshd service: /etc/rc.d/sshd start

If it’s the first time you enable SSHD, it will generate the keys for the first time.

At times, we might want to change date and time of a file, for record purposes. For example, when you copying log file from remote machine, when it’s extract on local machine, the date and time will reflect to current date time.

touch Command

To update the date and time of file, run;

touch -t ccyymmddhhMMSS filename

For more info, run;

man touch