Mac: Mac OS X Screen capturing shortcuts, without using any application

As I am writing blog posts, articles, books and any kind of documents that requires a screen shots on Mac OS, you will find a tool to do that by default packaged with Mac, Greb and preview tools.

Screenshots can be taken by using the Grab application included with OS X. It is located at /Applications/Utilities/Grab.

Preview can also be used to take screenshots, by using the "Take Screen Shot" submenu in the File menu.

Instead of using the applications above, for the sake of productivity, Mac OS X provides a keyboard shortcuts to control the screen shot taking instead of programs, and they are as the following:

1. Command-Shift-3:
   Take a screenshot of the screen, and save it as a file on the desktop
   
   
2. Command-Shift-4:
   then select an area: Take a screenshot of an area and save it as a file on the desktop
   
   
3. Command-Shift-4:
   then space, then click a window: Take a screenshot of a window and save it as a file on the desktop
   
   
4. Command-Control-Shift-3:
   Take a screenshot of the screen, and save it to the clipboard
   
   
5. Command-Control-Shift-4:
   then select an area: Take a screenshot of an area and save it to the clipboard
   
   
6. Command-Control-Shift-4:
   then space, then click a window: Take a screenshot of a window and save it to the clipboard
   
   
7. In Leopard and later,
   the following keys can be held down while selecting an area (via Command-Shift-4 or Command-Control-Shift-4):
   
   
   1. Space, to lock the size of the selected region and instead move it when the mouse moves
   2. Shift, to resize only one edge of the selected region
   3. Option, to resize the selected region with its center as the anchor point

Java SE 7: Refactoring your legacy java.io.File Code to elegant java.nio.file (NIO.2)

In my previous article, I have introduced all of the new functionalities, features and APIs, which are shipped with Java SE 7 release, and here we will see how to migrate or re-write your old IO to new NIO.2 code.

In my daily projects I am developing, I am depending extensively on I/O usage for exchanging files among my systems for integration, and there are a lot of boilerplate code, validations, exceptions checking and security related issues. Therefor I have decided to refactor my code especially critical one to Java SE 7 NIO.2 APIs.

In this article, I will show you a quick guide on how to refactor and map your legacy IO (Input/Output) code, which is prior to Java SE 7 ( java.io.File class was the only mechanism used for file I/O), to the new java.nio.file APIs which comes with rich and tremendous functionalities as part of Java SE 7 and above.

The Java 7 file I/O API JSR 203, has been completely re-architected in the Java SE 7 release; and because of that, you cannot swap one method for another method.

To use the rich functionality offered by the java.nio.file package, the easiest solution is to use the File.toPath method. If the previous statement is not sufficient for your needs, you must rewrite your file I/O code.

Before we dive into the mapping of the functionalities from legacy IO to the new one from Java 7 NIO, I have question to ask.

Why should I migrate from old IO to new NIO.2?

If you have developed more than a few applications based on java.io.File, then you should be familiar with not only its methods, but also its methods’ drawbacks.

For example, many of these methods do not throw exceptions when they fail, there is no real support for symbolic links, metadata access is inefficient, file renaming across platforms is inconsistent, and some methods do not scale, enhanced security and so on.

Let us begin the refactoring process:

The first milestone of refactoring java.io.File code may be considered the conversion of File objects into java.nio.file.Path objects through the java.io.File.toPath() method:

After conversion, you can exploit the Path features.

However, while this is the easiest solution, it may not always satisfy your needs.

Sometimes you will need to rewrite your file I/O code and align code to java.nio.file classes, and for this, you can use the one-by-one correspondence between the two APIs.

The following Table shows this correspondence; this table will make your code transition from Java 5 or 6 to Java 7 much easier:

Javadoc Description	java.io.File	java.nio.file
Class name correspondence	java.io.File	java.nio.file.Path
Tests this abstract pathname for equality with the given object	File.equals(Object)	Path.equals(Object)
Compares two abstract pathnames lexicographically	File.compareTo(File)	Path.compareTo(Path)
Returns the absolute pathname string of this abstract pathname	File.getAbsolutePath()	Path.toAbsolutePath()
Returns the absolute form of this abstract pathname	File.getAbsoluteFile()	Path.toAbsolutePath()
Returns the canonical pathname string of this abstract pathname	File.getCanonicalPath()	Path.toRealPath(LinkOption...) Path.normalize()
Returns the canonical form of this abstract pathname	File.getCanonicalFile()	Path.toRealPath(LinkOption...) Path.normalize()
Constructs a file: URI that represents this abstract pathname	File.toURI()	Path.toUri()
Tests whether the file denoted by this abstract pathname is a normal file	File.isFile()	Files.isRegularFile(Path, LinkOption ...)
Tests whether the file denoted by this abstract pathname is a directory	File.isDirectory()	Files.isDirectory(Path, LinkOption...)
Tests whether the file named by this abstract pathname is a hidden file	File.isHidden()	Files.isHidden(Path)
Tests whether the application can read the file denoted by this abstract pathname	File.canRead()	Files.isReadable(Path)
Tests whether the application can modify the file denoted by this abstract pathname	File.canWrite()	Files.isWritable(Path)
Tests whether the application can execute the file denoted by this abstract pathname	File.canExecute()	Files.isExecutable(Path)
Tests whether the file or directory denoted by this abstract pathname exists	File.exists()	Files.exists(Path, LinkOption...) Files.notExists(Path, LinkOption ...)
Creates the directory named by this abstract pathname	File.mkdir()	Files.createDirectory(Path, FileAttribute<?> ...)
Creates the directory named by this abstract pathname, including any necessary but nonexistent parent directories	File.mkdirs()	Files.createDirectories(Path, FileAttribute<?> ...)
Atomically creates a new, empty file named by this abstract pathname if and only if a file with this name does not yet exist	File.createNewFile()	Files.createFile(Path, FileAttribute<?> ...)
Returns an array of strings naming the files and directories in the directory denoted by this abstract pathname	File.list() File.listFiles()	Files.newDirectoryStream(Path)
Returns an array of strings naming the files and directories in the directory denoted by this abstract pathname that satisfy the specified filter	File.list(FilenameFilter) File.listFiles(FileFilter) File.listFiles(FilenameFilter)	Files.newDirectoryStream(Path, DirectoryStream.Filter<? super Path>) Files.newDirectoryStream(Path, String)
The length of the file denoted by this abstract pathname	File.length()	Files.size(Path)
Deletes the file or directory denoted by this abstract pathname	File.delete()	Files.delete(Path) Files.deleteIfExists(Path)
Renames the file denoted by this abstract pathname	File.renameTo(File)	Files.move(Path, Path, CopyOption)
Sets the owner or everybody’s execute permission for this abstract pathname	File.setExecutable(boolean, boolean)	Files.setAttribute(Path, String, Object, LinkOption...)
Sets the owner or everybody’s read permission for this abstract pathname	File.setReadable(boolean, boolean)	Files.setAttribute(Path, String, Object, LinkOption...)
Marks the file or directory named by this abstract pathname so that only read operations are allowed	File.setReadOnly()	Files.setAttribute(Path, String, Object, LinkOption...)
Sets the owner or everybody’s write permission for this abstract pathname	File.setWritable(boolean, boolean)	Files.setAttribute(Path, String, Object, LinkOption...)
Returns the time that the file denoted by this abstract pathname was last modified	File.lastModified()	Files.getLastModifiedTime(Path path, LinkOption... options)
Sets the last-modified time of the file or directory named by this abstract pathname	File.setLastModified(long)	Files.setLastModifiedTime(Path, FileTime)
Creates an empty file in the default temporary-file directory, using the given prefix and suffix to generate its name	File.createTempFile(String, String)	Files.createTempFile(String prefix, String suffix, FileAttribute<?>... attrs)
Creates a new empty file in the specified directory, using the given prefix and suffix strings to generate its name	File.createTempFile(String, String, File)	Files.createTempFile(Path dir, String prefix, String suffix, FileAttribute<?>... attrs)
Returns the size of the partition named by this abstract pathname	File.getTotalSpace()	FileStore.getTotalSpace()
Returns the number of unallocated bytes in the partition named by this abstract path name	File.getFreeSpace()	FileStore.getUnallocatedSpace()
Returns the number of bytes available to this virtual machine on the partition named by this abstract pathname	File.getUsableSpace()	FilesStore.getUsableSpace()
Lists the available file system roots	File.listRoots()	FileSystem.getRootDirectories()
Random access file	java.io.RandomAccessFile	java.nio.channels.SeekableByteChannel
Requests that the file or directory denoted by this abstract pathname be deleted when the virtual machine terminates	File.deleteOnExit()	Replaced by the DELETE_ON_CLOSE option
Combines two paths	new File(parent,"new_file")	parent.resolve("new_file")

Happy conversion, refactoring, mapping, and migrating IO from earlier JDKs to new JDK7 NIO2 :)

References:

1. JDK7: Part 1- The power of java 7 NIO.2(JSR 203)(important concepts).
2. File I/O(Featuring NIO.2).
3. Package java.nio.file.
4. Package java.io.
5. File class.

JavaZone 2013: Javapocalypse, "Without Java you can't live :)"

"It's supposed to write once, run everywhere. But it's more like write once, ruin everything..."

http://www.javazone.no

Git: The most commonly used git commands

On my daily bases working with git (DVCS), I found that the most common commands I am using every time are the following commands.

And I have made some aliases for some of them for eases of access and use; check this link on how to make aliases or shortcuts for your commands.

Command	Work description
add	Add file contents to the index. When new or modified files are ready for the next commit, they must first be staged with the add command. Files can be staged one by one, by folder name, or by wildcard pattern.
bisect	Find by binary search the change that introduced a bug
branch	List, create, or delete branches
checkout	Checkout a branch or paths to the working tree
clone	Clone a repository into a new directory
commit	Once all desired files are added and staged, a commit command transactionally saves the pending additions to the local repository.
diff	Show changes between commits, commit and working tree, etc
fetch	Download objects and refs from another repository
grep	Print lines matching a pattern
init	Create an empty Git repository or reinitialize an existing one
log	Show commit logs
merge	Join two or more development histories together
mv	Move or rename a file, a directory, or a symlink
pull	Fetch from and merge with another repository or a local branch
push	Update remote refs along with associated objects
rebase	Rebasing is the rewinding of existing commits on a branch with the intent of moving the branch start point forward, then replaying the rewound commits. This allows developers to test their branch changes safely in isolation on their private branch just as if they were made on top of the mainline code, including any recent mainline bug fixes.
reset	Reset current HEAD to the specified state
rm	Remove files from the working tree and from the index
show	Show various types of objects
status	Show the working tree status, and check the current status of a project’s local directories and files, such as modified, new, deleted, or untracked.
tag	Git provides tagging to mark a specific commit in your timeline of changes, and serve as a useful identifier in history. A tag can be created for any commit in history by passing the commit hash. If no commit hash is provided, the most recent commit (i.e. HEAD) will be used by default.

For more information of each command and its related options, from command line on windows or terminal on Mac issue the following command

'git help ' to See more information on a specific command.

Mac: How to prevent your Mac from Sleeping !!!

While I am downloading, updating programs or even my Mac, after a while I found my Mac goes to sleep automatically even if it plugs to the power adapter.

The main problem here is that, the wireless network get interrupted and no more download in progress, unless I return it back from sleep mode.

There are 2 solutions for this issue:

1. Changing the computer sleeping option from energy saving option under system preferences, as the following:
   From Mac general menu click on Mac icon → System preferences → Energy Saver → change your Computer sleep slider to “Never”, on battery and power adapter. (It doesn’t work for me). I will check and try other options I may miss.
   
   
2. Use Caffeine program, it could be downloaded from Mac App store or from here, it's free application and very popular one.

I prefer the second option, mainly because there are times when I want my Mac book to sleep and don't want to keep changing the settings. Just one click of the coffee cup does it.

Caffeine

Caffeine is a tiny program that puts an icon in the right side of your menu bar. Click it to prevent your Mac from automatically going to sleep, dimming the screen or starting screen savers. Click it again to go back. Hold down the Command key while clicking to show the menu.

The menu now has a sub-menu for deactivating Caffeine automatically after a number of minutes.

Works just great. Computers need no sleep, people do.:)