Category Archives: Mac OS X Tips & Tricks

#MacOSX : Taking Screenshots

You will be surprised but even without stamp key on the keyboard you can take screenshots whitout 3rd party apps! ­čśÇ

There are several keyboard combinations that can be used to take screenshots in Mac OS X. The SystemUIServer process handles these commands.

  • 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 clipboar.

From Mac OS X 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.

NOTE: different versions of Mac OS X have different formats for screenshots.

NOTE2: in Mac OS X 10.4 and later, the default screenshot format can be changed, by opening Terminal app and typing :
defaults write 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.


#MacOSX : Quick Look

Quick Look is a powerfull feature of Mac OS X which is activated when hitting space after file(s) selection; let’s see why:

  1. Multiformat Support: can open an amusing number of file format including, but not limited to:
    PDFs, HTML, QuickTime readable media, plain text and RTF text documents, Apple Keynote, Pages and Numbers, ODF documents, Microsoft Word, Excel, and PowerPoint files (including OOXML), RAW camera images.
  2. Plugins: support for additional formats can be achieved via use of 3rd party plug-ins.
  3. Index Sheet: if you select multiple files before activating Quick Look, you’ll just be shown a preview of the first file. Clicking Index Sheet is just like using expos├ę, only with the previews rather than windows.
  4. Slideshow Mode: when using Quick Look on multiple images, there is a play button at the bottom to start a slideshow.
  5. Zooming: if you activate Quick Look on an image, hold down the Option key and you will notice that the cursor changes to a magnifying glass. Now, using the scroll wheel you can zoom in and out.
  6. Keyboard Navigation: while you are previewing a file with Quick Look, you can still use the keyboard to navigate to other files. In column view this is easily done with the arrow keys. In the other views, use Cmd-DOWN and Cmd-UP to go into and out of folders.
  7. Trashed Files: can preview trashed files without moving them out.

NOTE1: Quick Look has been introduced in Mac OS X Leopard and it is still present in Mac OS X Lion.

NOTE2: Quick Look is just enough to prefer Mac OS X over Windows! ­čśŤ

#MacOSX : Disable Hibernation & SSD Tweaks

SSD are based on NAND Flash which have limited writes life. Currently 25nm chips support 3000-5000 cycles then they become read only.

This limitation makes very important avoid unneeded writes on the disk.

Moreover power save technologies can give some trouble (of course on SandForce controllers).

So this are some steps to Tweak your host system to give you the best experience:

  1. Turn off hibernation. To do this, open terminal app and type:
    sudo pmset -a hibernatemode 0

    Enter admin password and let’s do it the magic.
    This will prevent GB of writes every time you close the lid of your notebook.

  2. Remove unused hibernation file to free up as much space as your RAM:
    sudo rm /var/vm/sleepimage
  3. Open System Preferences and go to Energy Saver, than uncheck
    Put the hard disk(s) to sleep when possible
    both on Battery and Power Adapter tabs.
    This will prevent disk freezes and beachballs.
  4. If you have a SATA 2 interface and a Nvidia chipset on your Mac, check to have 3 Gbps Negotiated Link Speed.
    Go to Serial-ATA section in System Information app to take a look of your disk(s).
    This will ensure optimal performance of SSD.

NOTE: there are more Hacks, like enabling TRIM for non Apple supported SSDs but they give more troubles that other therefore I advice against to engage in similar enterprises.

NOTE 2: WARNING!!! Apple MacBook Air and MacBook Pro Update 2.0 seems to change the way “safesleep” is handled. If you currently have safesleep disabled in order to free up the drive space required by the sleep image, this will cause it to come back and even setting hibernatemode = 0 won’t change it. Quick untested FIX:

cd /var/vm
sudo rm sleepimage
sudo ln -s /dev/null sleepimage
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