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Using unset vs. setting a variable to empty
...t; unset var
/home/user1> echo $var
-bash: var: unbound variable
So really, it depends on how you are going to test the variable.
I will add that my preferred way of testing if it is set is:
[[ -n $var ]] # True if the length of $var is non-zero
or
[[ -z $var ]] # True if zero length
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How can you diff two pipelines in Bash?
...dev/fd/63 to get a filename that the command can open and read from to actually read from an already-open file descriptor that bash set up before exec'ing the command. (i.e. bash uses pipe(2) before fork, and then dup2 to redirect from the output of quux to an input file descriptor for diff, on fd ...
What's the right OAuth 2.0 flow for a mobile app
...nt authorization flow (defined in Section 4.2 of OAuth 2.0 [RFC6749]) generally works with the practice of performing the authorization request in the browser and receiving the authorization response via URI-based inter-app communication.
However, as the implicit flow cannot be protected by PKCE [RF...
How to save traceback / sys.exc_info() values in a variable?
...traceback.format_exc()
...
>>> print var
Traceback (most recent call last):
File "<stdin>", line 2, in <module>
ValueError: invalid literal for int() with base 10: 'k'
You should however take a look at the traceback documentation, as you might find there more suitable metho...
How to call a method after a delay in Android
I want to be able to call the following method after a specified delay.
In objective c there was something like:
31 Answer...
Memory address of variables in Java
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Actually, the identity hash code cannot change, otherwise the contract of hashCode() would be violated.
– Matt McHenry
Jun 28 '13 at 18:36
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When serving JavaScript files, is it better to use the application/javascript or application/x-javas
...r js in your pages, IE7 and IE8 will not run your script! Blame Microsoft all you want, but if you want most people to run your pages use text/javascript.
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Passing Parameters JavaFX FXML
...tes different mechanisms for passing parameters to FXML controllers.
For small applications I highly recommend passing parameters directly from the caller to the controller - it's simple, straightforward and requires no extra frameworks.
For larger, more complicated applications, it would be worthwh...
How can I check the system version of Android?
...ow how can I check the system version (e.g. 1.0 , 2.2 , etc.) programatically?
13 Answers
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String.format() to format double in java
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String.format("%1$,.2f", myDouble);
String.format automatically uses the default locale.
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