Tips and Tricks » Tips & Tricks

Flushing / clearing DNS in Mac OSX

admin — Tue, 11 Oct 2011 18:08:16 +0000

Below is how to clear / flush the DNS cache in Mac OSX.

Open the terminal (Finder -> Applications -> Utilities -> Terminal)
In case your operating system is ‘Leopard’ (10.5.*) or ‘Snow Leopard’ (10.6.*), issue the following command:

dscacheutil -flushcache

Otherwise, for older operating systems, issue the following command:

lookupd -flushcache

This is the equivalent of the following Windows command: ipconfig /flushdns…

Deleting a file, the name of which starts with a hyphen (Linux)

admin — Mon, 02 May 2011 10:08:27 +0000

You might have come across a difficulty in deleting a file in Linux whose name starts with a dash/hyphen.

Adding an escape character (e.g. rm -rf \-filename) or quoting the file name (e.g. rm -rf “-filename”) will not do the job.

The solution is simple: explicitly provide the full or relative path to the file. e.g.:

rm -rf /path/to/-file

or the following – if for instance your current working directory is the one containing the file in question

rm -rf ./-file…

Mac users: turn colors into negative

admin — Thu, 24 Mar 2011 23:13:16 +0000

Are you a mac user? try the following keyboard combination:

cmd + alt (option) + ctrl + 8

Colors are instantly inverted, giving the entire screen a negative-photography like feel.

Hit the same combination to restore the colors.…

Linux: finding files modified or accessed at a certain time

admin — Sun, 20 Feb 2011 19:10:11 +0000

The ‘find’ utility is quite handy when used with the proper parameters. Below is a few ways to find files/folders based on the time they were accessed or modified.

Example 1:

find /path/to/folder -type f -name “*.txt” -mtime -5

This will find ‘files’ (-type f) within the folder /path/to/folder (or one of its sub directories), whose name ends with ‘.txt’, and which were modified (mtime) less than 5 days ago

Example 2:

find /path/to/folder -type d -name “stat*” -mtime +10

This would find ‘directories’ (-type d) within the folder /path/to/folder (or one of its subdirectories), whose name …

Facebook’s new photo viewer

admin — Sat, 12 Feb 2011 22:25:45 +0000

Facebook recently introduced a new way of browsing photos and albums. The new photo viewer uses the lightbox technique whereby the page is dimmed and a box is overlaid with a larger version of the selected image.

Some of the improvements it brings are the ability to stay on the page without having to go back in your browser’s history (you simply hit the close ‘x’ button and you’re back to where you were), faster photo flipping/browsing and the ability to download a high res version of the image (if available).

For those who hate this lightbox preview, you may …

Forcing links that open in a ‘new window’ to open in a ‘new tab’

admin — Sat, 07 Aug 2010 12:59:32 +0000

Do you want to force links that open in a new window to open in a new tab instead? The answer is pretty simple.

Firefox

Type the following in the url bar: about:config
Edit the following variables:
- browser.link.open_external -> 3
- browser.link.open_newwindow -> 3
- browser.link.open_newwindow.restriction -> 0
If any of those variables is not yet defined, simply right click and select ‘new->integer’, enter the variable name then its integer value.

IE8

Simply:

Go to: tools -> internet options
Then make sure you select ‘always open pop-ups in a new tab‘ under ‘when a pop-up is encountered‘

That’s …

Enabling telnet in windows vista

admin — Fri, 06 Nov 2009 08:59:14 +0000

Some of you may be missing the good old command-line telnet client. The thing is that vista has this client disabled by default. The good news is that you can easily install/enable it. To do so, follow these steps:

Go to Control Panel
Click on ‘Programs’
Under ‘Programs and Features’, click on ‘Turn windows features on or off’
Wait a bit for the list to be compiled
Tick ‘Telnet client‘ and hit ‘OK’ then wait for it to be installed

You may now open a command prompt and use telnet hostname port

Good luck…

Konami Code

admin — Tue, 09 Jun 2009 14:45:13 +0000

The ‘Konami code’ fad is back!

For those of you who don’t know, Konami code (a.k.a Konami Command) is a cheat code that was used in several games back in the day.

It has been introduced not long ago on several websites. Upon entering this cheat code, some ‘secret’ is revealed or a page is unlocked.

The sequence is: Up, Up, Down, Down, Left, Right, Left, Right, B, A

Some of the famous websites that make use of it are: digg.com, facebook.com
For instance, hitting the above sequence on any story page on digg would change the way comments are …

Traffic forwarding on linux using IPTABLES

admin — Mon, 18 May 2009 08:24:28 +0000

IPTables allows you to easily setup rules for packet filtering/forwarding.

So, to keep it short and simple: assume you’d like to forward any traffic coming to your machine (192.168.0.1) on port 80 to machine2 (192.168.0.2) on port 8080 then:

- Enable port forwarding:

echo 1 > /proc/sys/net/ipv4/ip_forward

- Now add the rules:

iptables -t nat -A PREROUTING -p tcp -d 192.168.0.1 –dport 80 -j DNAT –to 192.168.0.2:8080

iptables -t nat -A POSTROUTING -d 192.168.0.2 -j MASQUERADE

The -p tcp flag specifies that the protocol is TCP (as opposed to UDP, ICMP for example).

The -d 192.168.0.1 flag specifies that the …

Google search tips

admin — Sun, 01 Mar 2009 15:44:22 +0000

‘Face’ photos
When searching for images, you could narrow down your search to ‘faces’. Simply, append ‘&imgtype=face’ to the end of the google images search url.
So if you’re searching for Robert De Niro, try doing it with ‘face’ as image type

File Types
You could specify the type of file you’re looking for. Simply append ‘filetype: type’ to your search query. So if you’re looking for an excel file related to subject Foo, then search for: ‘Foo filetype:xsl’

Site limitation
If you’d like to narrow down your search results to those coming from a certain website, you may …