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Test if a variable is set in bash when using “set -o nounset”
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Nope, -, +, :+, and :- are all supported. The former detect whether the variable is set, and the latter detect whether it is set or empty. From man bash: "Omitting the colon results in a test only for a parameter that is unset."
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Google Maps Android API v2 Authorization failure
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Steps:
to ensure that device has Google Play services APK
to install Google Play Service rev. more than 2
to create project at https://code.google.com/apis/console/
to enable "Google Maps Android API v2"
to register of SHA1 in project (NOW, YOU NEED WRITE SHA1;your.app.package.name) ...
What is the best way to detect a mobile device?
...igator.userAgent.toLowerCase()));
Now $.browser will return "device" for all above devices
Note: $.browser removed on jQuery v1.9.1. But you can use this by using jQuery migration plugin Code
A more thorough version:
var isMobile = false; //initiate as false
// device detection
if(/(android|b...
Replacement for “rename” in dplyr
...which does keep it consistent with the rest of the dplyr functions. Personally, I don't think of it as a problem--you get used to new things quickly especially when it means a significant speedup in your data processing.
– vergilcw
Feb 3 '14 at 15:47
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What is the difference between Cygwin and MinGW?
...Unix-based applications to Windows much easier, by emulating many of the small details that Unix-based operating systems provide, and are documented by the POSIX standards. Your application can use Unix feature such as pipes, Unix-style file and directory access, and so forth, and it can be compile...
How can I increment a char?
...and C. How can I increment a char? In Java or C, chars and ints are practically interchangeable, and in certain loops, it's very useful to me to be able to do increment chars, and index arrays by chars.
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Is there any way to change input type=“date” format?
...riting Chrome, Edge, Firefox, and Opera have date support (see here). They all display a date picker and format the text in the input field.
Desktop devices
For Chrome, Firefox, and Opera, the formatting of the input field's text is based on the browser's language setting. For Edge, it is based on...
How do I upgrade my ruby 1.9.2-p0 to the latest patch level using rvm?
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First of all, update your RVM installation by running rvm get stable.
To make sure you're running the new RVM version, you'll then need to run rvm reload (or just open a new terminal).
Once that's done, you can ask RVM to list the r...
Python: How to create a unique file name?
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I didn't think your question was very clear, but if all you need is a unique file name...
import uuid
unique_filename = str(uuid.uuid4())
share
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improve this answer
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Rotating a two-dimensional array in Python
...2]]
This list is passed into zip() using argument unpacking, so the zip call ends up being the equivalent of this:
zip([3, 4],
[1, 2])
# ^ ^----column 2
# |-------column 1
# returns [(3, 1), (4, 2)], which is a original rotated clockwise
Hopefully the comments make it clear what zip ...