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Allowed characters in Linux environment variable names
...EE Std
1003.1-2001 consist solely of uppercase letters, digits, and the '_'
(underscore) from the characters
defined in Portable Character Set and
do not begin with a digit. Other
characters may be permitted by an
implementation; applications shall
tolerate the presence of such names.
...
How do you round to 1 decimal place in Javascript?
...)
You might want to create a function for this:
function roundedToFixed(_float, _digits){
var rounded = Math.pow(10, _digits);
return (Math.round(_float * rounded) / rounded).toFixed(_digits);
}
share
|
...
Extending the User model with custom fields in Django
...o.contrib.auth.models import User
from django.db.models.signals import post_save
class UserProfile(models.Model):
user = models.OneToOneField(User)
#other fields here
def __str__(self):
return "%s's profile" % self.user
def create_user_profile(sender, instance, creat...
What are rvalues, lvalues, xvalues, glvalues, and prvalues?
... three: lvalue, xvalue, prvalue. A Venn diagram would look like this:
______ ______
/ X \
/ / \ \
| l | x | pr |
\ \ / /
\______X______/
gl r
Examples with functions:
int prvalue();
int& lvalue();
int&& xvalue();
But al...
How to “EXPIRE” the “HSET” child key in redis?
... mentioning:
When having a hash, the structure basically looks like:
hash_top_key
- child_key_1 -> some_value
- child_key_2 -> some_value
...
- child_key_n -> some_value
Since we want to add TTL to the child keys, we can move them to top keys. The main point is that the key now ...
How to detect if a script is being sourced
...
This seems to be portable between Bash and Korn:
[[ $_ != $0 ]] && echo "Script is being sourced" || echo "Script is a subshell"
A line similar to this or an assignment like pathname="$_" (with a later test and action) must be on the first line of the script or on the...
How do I mock a service that returns promise in AngularJS Jasmine unit test?
...ce;
beforeEach(module('app.myService'));
beforeEach(inject( function(_myService_, myOtherService, $q){
myService = _myService_;
spyOn(myOtherService, "makeRemoteCallReturningPromise").and.callFake(function() {
var deferred = $q.defer();
deferred.resolve('Remote call res...
Loop backwards using indices in Python?
...as no way to tell the xrange to go backwards... (Since Python 2.6 it calls __reversed__().)
– Robert Siemer
Jun 21 '12 at 18:31
...
What happens to global and static variables in a shared library when it is dynamically linked?
...yntax similar to the function export/import syntax, i.e.:
#ifdef COMPILING_THE_DLL
#define MY_DLL_EXPORT extern "C" __declspec(dllexport)
#else
#define MY_DLL_EXPORT extern "C" __declspec(dllimport)
#endif
MY_DLL_EXPORT int my_global;
When you do that, the global variable is added to the list of...
What's a good way to extend Error in JavaScript?
...){
Object.setPrototypeOf(CustomError, Error);
} else {
CustomError.__proto__ = Error;
}
Alternative: use Classtrophobic framework
Explanation:
Why extending the Error class using ES6 and Babel is a problem?
Because an instance of CustomError is not anymore recognized as such.
class Cus...