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Grep characters before and after match?
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3 characters before and 4 characters after
$> echo "some123_string_and_another" | grep -o -P '.{0,3}string.{0,4}'
23_string_and
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How can I check the system version of Android?
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Check android.os.Build.VERSION.
CODENAME: The current development codename, or the string "REL" if this is a release build.
INCREMENTAL: The internal value used by the underlying source control to represent this build.
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What's the best way to check if a file exists in C?
...exists
} else {
// file doesn't exist
}
You can also use R_OK, W_OK, and X_OK in place of F_OK to check for read permission, write permission, and execute permission (respectively) rather than existence, and you can OR any of them together (i.e. check for both read and write permission using R...
Passing Objects By Reference or Value in C#
... have always thought that non-primitive variables were passed by reference and primitive values passed by value.
7 Answers
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How can I tell if I'm running in 64-bit JVM or 32-bit JVM (from within a program)?
... the HotSpot FAQ:
When writing Java code, how do I distinguish between 32 and 64-bit operation?
There's no public API that allows you to distinguish between 32 and 64-bit operation. Think of 64-bit as just another platform in the write once, run anywhere tradition. However, if you'd like to write c...
dd: How to calculate optimal blocksize? [closed]
...culate the optimal blocksize when running a dd ? I've researched it a bit and I've not found anything suggesting how this would be accomplished.
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ORA-00054: resource busy and acquire with NOWAIT specified or timeout expired
...cked by some query. For example, you may have executed "select for update" and have not yet committed/rollbacked and fired another select query. Do a commit/rollback before executing your query.
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Check if a String contains numbers Java
...the \\d+ (double backslash I think is just to escape the second backslash) and \d+ means a digit from 1 time to infinite.
– Giudark
Sep 29 '16 at 0:11
6
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Section vs Article HTML5
... or
subjects, or to define the different sections of a single article.
And then displays an image that I cleaned up:
It also describes how to use the <article> tag (from same W3 link above):
<article> is related to <section>, but is distinctly different.
Whereas <se...
Why is creating a Thread said to be expensive?
...a fair bit of work involved:
A large block of memory has to be allocated and initialized for the thread stack.
System calls need to be made to create / register the native thread with the host OS.
Descriptors need to be created, initialized and added to JVM-internal data structures.
It is also e...