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What is the $? (dollar question mark) variable in shell scripting? [duplicate]
...is called by the exit() ANSI C function, and indirectly when you do return from main.
the process that called the exiting child process (Bash), often with fork + exec, can retrieve the exit status of the child with the wait system call
Consider the Bash code:
$ false
$ echo $?
1
The C "equivalen...
How to add to an existing hash in Ruby
... have keys of nearly any type you can throw at it. This makes it different from the dictionary structures you find in other languages.
It's important to keep in mind that the specific nature of a key of a hash often matters:
hash = { :a => 'a' }
# Fetch with Symbol :a finds the right value
has...
How do I improve ASP.NET MVC application performance?
...neration
is a expensive activity. Deferring to the client side your server from an
unnecessary burden, and allows you to work with graphs locally without make a new
request (i.e. Flex charting, jqbargraph, MoreJqueryCharts).
Use CDN's for scripts and media content to improve loading on the client s...
Do you need to dispose of objects and set them to null?
...o properly explain that aspect of CLR, I'll need to explain a few concepts from C++ and C#.
Actual variable scope
In both languages the variable can only be used in the same scope as it was defined - class, function or a statement block enclosed by braces. The subtle difference, however, is that i...
'transform3d' not working with position: fixed children
...uld be to avoid transforms for the time being if you're going to use fixed from inside of it.
– saml
Aug 26 '13 at 15:56
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How to find the foreach index?
.... I think it's better to just create a variable outside the loop and count from there, increasing it with vatiable++; on each iteration. The traditional way, but has always worked.
– Jomar Sevillejo
Oct 30 '15 at 1:22
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PHP Warning: PHP Startup: Unable to load dynamic library
...angest part. For this type of error, I'd assume that php would crash right from the start. Instead I get my page, but my logger is logging this error. Weird huh?
– B T
Jun 10 '11 at 5:52
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How do I ignore a directory with SVN?
... 'cache' dir still will be listed in 'svn st'. Is there a way to remove it from the view? (without delete from the disk)
– Tom Brito
Aug 1 '16 at 20:45
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Case-insensitive search in Rails model
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@botbot's comment does not apply to strings from user input. "#$$" is a little-known shortcut for escaping global variables with Ruby string interpolation. It's equivalent to "#{$$}". But string interpolation doesn't happen to user-input strings. Try these in Irb to se...
Uppercase Booleans vs. Lowercase in PHP
...t I often found myself writing TRUE or FALSE in Javascript after switching from PHP. Using lower case in PHP fixed this one for good.
– Sz.
Jun 19 '13 at 10:45
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