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How does database indexing work? [closed]
...a section for data, a pointer to the location of the next node (or block), and both need not be stored contiguously.
Due to the fact that a number of records can only be sorted on one field, we can state that searching on a field that isn’t sorted requires a Linear Search which requires N/2 block...
How to find all serial devices (ttyS, ttyUSB, ..) on Linux without opening them?
...ll TTY devices but you might want to exclude those pesky virtual terminals and pseudo terminals. I suggest you examine only those which have a device/driver entry:
# ll /sys/class/tty/*/device/driver
lrwxrwxrwx 1 root root 0 2012-03-28 19:07 /sys/class/tty/ttyS0/device/driver -> ../../../bus/pnp...
Why fragments, and when to use fragments instead of activities?
In Android API 11+, Google has released a new class called Fragment .
11 Answers
11
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Chained method calls indentation style in Python [duplicate]
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The need for this style becomes more obvious as method names get longer and as methods start taking arguments:
return some_collection.get_objects(locator=l5) \
.get_distinct(case_insensitive=True) \
.filter(predicate=query(q5)) \
...
How to randomize (shuffle) a JavaScript array?
...github.com/coolaj86/knuth-shuffle
You can see a great visualization here (and the original post linked to this)
function shuffle(array) {
var currentIndex = array.length, temporaryValue, randomIndex;
// While there remain elements to shuffle...
while (0 !== currentIndex) {
//...
How to write inline if statement for print?
...n Python 2.5)
expression_if_true if condition else expression_if_false
And note, that both print a and b = a are statements. Only the a part is an expression. So if you write
print a if b else 0
it means
print (a if b else 0)
and similarly when you write
x = a if b else 0
it means
x = ...
Check Whether a User Exists
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You can also check user by id command.
id -u name gives you the id of that user.
if the user doesn't exist, you got command return value ($?)1
And as other answers pointed out: if all you want is just to check if the user exists, use if with id directly, as i...
HTTP vs HTTPS performance
Are there any major differences in performance between http and https? I seem to recall reading that HTTPS can be a fifth as fast as HTTP. Is this valid with the current generation webservers/browsers? If so, are there any whitepapers to support it?
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Difference between author and committer in Git?
... is the person who originally wrote the code. The committer, on the other hand, is assumed to be the person who committed the code on behalf of the original author. This is important in Git because Git allows you to rewrite history, or apply patches on behalf of another person. The FREE online Pro G...
Is there any difference between the `:key => “value”` and `key: “value”` hash notations?
Is there any difference between :key => "value" (hashrocket) and key: "value" (Ruby 1.9) notations?
5 Answers
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