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Add a new element to an array without specifying the index in Bash
...mb Guy points out, it's important to note whether the array starts at zero and is sequential. Since you can make assignments to and unset non-contiguous indices ${#array[@]} is not always the next item at the end of the array.
$ array=(a b c d e f g h)
$ array[42]="i"
$ unset array[2]
$ unset array...
git-diff to ignore ^M
...ts that you should make sure to only use \n as a newline character in git-handled repos. There's an option to auto-convert:
$ git config --global core.autocrlf true
Of course, this is said to convert crlf to lf, while you want to convert cr to lf. I hope this still works …
And then convert you...
How do I choose between Semaphore and SemaphoreSlim?
... documentation states that the SemaphoreSlim is a lightweight alternative and doesn't use Windows Kernel semaphores. This resource states that the SemaphoreSlim is much faster. In what situations does the SemaphoreSlim make more sense over the Semaphore and vice versa?
...
How does the ThreadStatic attribute work?
...IL level, in the .NET jit compiler. Compilers that emit to IL like VB.NET and C# don't need to know anything about Win32 TLS in order to emit IL code that can read and write a variable that has the ThreadStatic attribute. There's nothing special about the variable as far as C# knows - it's just a ...
select * vs select column
If I just need 2/3 columns and I query SELECT * instead of providing those columns in select query, is there any performance degradation regarding more/less I/O or memory?
...
Running multiple AsyncTasks at the same time — not possible?
I'm trying to run two AsyncTasks at the same time. (Platform is Android 1.5, HTC Hero.)
However, only the first gets executed. Here's a simple snippet to describe my problem:
...
Detect 7 inch and 10 inch tablet programmatically
...= metrics.heightPixels;
This will return the absolute value of the width and the height in pixels, so 1280x720 for the Galaxy SIII, the Galaxy Nexus etc.
This isn't usually helpful on its own, as when we're working on Android devices, we usually prefer to work in density independent pixels, dip....
Why malloc+memset is slower than calloc?
...se it can skip memset() entirely. In other cases, calloc() can even cheat and not allocate any memory! However, malloc()+memset() will always do the full amount of work.
Understanding this requires a short tour of the memory system.
Quick tour of memory
There are four main parts here: your prog...
Securely storing environment variables in GAE with app.yaml
I need to store API keys and other sensitive information in app.yaml as environment variables for deployment on GAE. The issue with this is that if I push app.yaml to GitHub, this information becomes public (not good). I don't want to store the info in a datastore as it does not suit the project...
Error: could not find function … in R
I am using R and tried some.function but I got following error message:
10 Answers
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