iOS 7, the latest version of Apple's mobile operating system, is now available for download. The update can be installed on any compatible iPhone, iPad, or iPod touch by visiting your device's settings menu, choosing "general," and then selecting the software update option. iOS 7 can also be installed with the help of the newly-released iTunes 11.1 on Windows and OS X. (You'll want to download that anyway, as it's required to sync music, videos, and other content to your device.)
The most immediate and striking change in Apple's latest OS is the all-new user interface designed under the eye of Jony Ive. iOS has been given a comprehensive visual makeover intended to make the overall user experience "simpler, more useful, and more enjoyable." But changes aren't just skin deep; iOS 7 introduces new features like iTunes Radio, AirDrop sharing, Control Center, and improved card-style multitasking.
Note that not all of Apple's latest features are available across all iOS hardware. If you're running the new software on anything older than an iPhone 5 or iPad 4, you stand to lose out on some functionality. Please find below those differences matrix.
Command-Shift-3: Take a screenshot of the screen, and save it as a file on the desktop
Command-Shift-4, then select an area: Take a screenshot of an area and save it as a file on the desktop
Command-Shift-4, then space, then click a window: Take a screenshot of a window and save it as a file on the desktop
Command-Control-Shift-3: Take a screenshot of the screen, and save it to the clipboard
Command-Control-Shift-4, then select an area: Take a screenshot of an area and save it to the clipboard
Command-Control-Shift-4, then space, then click a window: Take a screenshot of a window and save it to the clipboard
In Leopard and later, the following keys can be held down while selecting an area (via Command-Shift-4 or Command-Control-Shift-4):
Space, to lock the size of the selected region and instead move it when the mouse moves
Shift, to resize only one edge of the selected region
Option, to resize the selected region with its center as the anchor point
Formats
Different versions of Mac OS X have different formats for screenshots.
Mac OS X 10.2 (Jaguar): jpg
Mac OS X 10.3 (Panther): pdf
Mac OS X 10.4 (Tiger) and later: png
In Mac OS X 10.4 and later, the default screenshot format can be changed, by opening Terminal (located at /Applications/Utilities/Terminal) and typing in:
defaults write com.apple.screencapture type image_format
killall SystemUIServer
Where image_format is one of jpg, tiff, pdf, png, bmp or pict (among others). If you omit the second line, you will need to log out and in again for the change to take effect.
Grab and Preview
Instead of using the keyboard shortcuts above, screenshots can be taken by using the Grab application included with Mac OS X. It is located at /Applications/Utilities/Grab.
In Mac OS X 10.4, the Preview application can also be used to take screenshots, by using the Grab submenu in the File menu.
From the Terminal
The screencapture command in the Terminal can also be used to capture screenshots, and is useful for scripts. Here is an example.
After upgrading to 10.8.2 I have got a problem with adding a new entry into hosts file: the update was recognised only after system restart. But a more easy solution was just to flash DNS cache! So,
... flushing your DNS cache in Mac OS X is actually really easy, and there are two different commands to use, one for Leopard and for Tiger. Depending on your version of OS X, open your Terminal and follow the appropriate directions below:
Flushing DNS Cache in OS X Lion (10.7) and OS X Mountain Lion (10.8)
Launch Terminal and enter the following command, you will need to enter an administrative password:
sudo killall -HUP mDNSResponder
Note the dscacheutil still exists in 10.7 and 10.8, but the official method to clear out DNS caches is through killing mDNSResponder. You can also find that process running in Activity Monitor.
Flush DNS Cache in Mac OS X 10.5, Mac OS X 10.6
Launch Terminal and issue the following command:
dscacheutil -flushcache
All done, your DNS has been flushed. On a side note, the dscacheutil is interesting in general and worth taking a look at, try the -statistics flag instead for some stats.
Flush your DNS Cache in Mac OS X 10.4 Tiger
Type the following command in the Terminal:
lookupd -flushcache
That’s it - now your DNS settings should be as you intended them to be :-)
When you are working on the Linux command line and you come across a large file or a large number of files in which you need to replace a certain text with another, finding and pasting over each instance of the text can be a bit time consuming. Well, worry no more. Linux has just the solution for you. Here’s a way to find and replace a string of text in one or more files automatically.
For the purpose of this exercise we will use a Linux command line tool called “sed”. ”sed” is a very powerful and versatile tool, and a lot can be written about its capabilities. We are using a very limited aspect of “sed” here. I would definitely recommend that you read up a little more on “sed” if you find this aspect of it interesting.
We are going to use the following syntax to find and replace a string of text in a file:
# sed -i 's/[orginal_text]/[new_text]/' filename.txt
Say you have a file called “database.txt” with numerous instances of the IP address of your database server in it. You have just switched to a new database server and need to update it with the new server’s IP address. The old IP address is 192.168.1.16 and the new one is 192.168.1.22. Here’s how you go about it:
Now open the file “database.inc” and check to see if the new IP address has taken place of your old one. Here’s the breakup of the above command. First you call the “sed” command. Then you pass it the parameter “-s” which stands for “in place of”. Now we use a little bit of regular expressions, commonly known as “regex” for the next bit. The “s” in the quoted string stands for “substitute”, and the “g” at the end stands for “global”. Between them they result in a “global substitution of the the string of text you place in between them.
You can optionally skip the “g” at the end. This means that the substitution will not be global, which practically translates to the substitution of only the first instance of the string in a line. So if you had a line with multiple instances of the text you are trying to replace, here’s what will happen
Here comes the real magic. Now, say you want to change a string of text not just in a single file, but in the entire directory you are in. There are a number of text files in which you need to find and replace the “wine” with “champagne”.
# find . -maxdepth 1 -name "*.txt" -type f -exec sed -i 's/wine/champagne/' {} \
We use the find command to get a list of all the text files in the current directory. That’s the “find . -maxdepth 1 -name “*.txt” -type f” part. “find . maxdepth 1″ tell the computer to look in the current directory and go no deeper than the current directory. The ‘-name ”*.txt”‘ part tells find to only list files with the extension of “.txt”. Then the “-type f” section specifies that “find” should only pick exactly matching files. Finally the “-exec” part tells “find” to execute the command that follows, which, in this case, is the “sed” command to replace the text – “sed -i ‘s/wine/champagne/’ {} \”.
I realize that the above command seems complicated. However, once you use it a little bit you will realize that it is probably worth noting it down and using it. Now try changing a string of text in multiple levels of directories.
After Xcode installation and trying to build mc I've got:
configure: error: C compiler cannot create executables
Google offers to install Xcode correctly (this is a different story however) or to reinstall it. Hmmm. Good idea but in my case the following simple action solved the issue: symlinks for compilers - that's all ! KISS