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Controlling a USB power supply (on/off) with Linux
Is it possible to turn on/off power supplies from USB manually with Linux?
10 Answers
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Template function inside template class
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template <class T>
template <class U>
void MyClass<T>::foo() { /* ... */ }
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How to combine paths in Java?
...ubDirectory, "baz.txt");
If you want it back as a string later, you can call getPath(). Indeed, if you really wanted to mimic Path.Combine, you could just write something like:
public static String combine(String path1, String path2)
{
File file1 = new File(path1);
File file2 = new File(f...
Shell script to send email [duplicate]
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Don't forget to install the mail program first: sudo apt-get install mailutils
– Yonatan Simson
Jan 25 '17 at 16:13
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How to select from subquery using Laravel Query Builder?
...y there is no method to create subquery in FROM clause, so you need to manually use raw statement, then, if necessary, you will merge all the bindings:
$sub = Abc::where(..)->groupBy(..); // Eloquent Builder instance
$count = DB::table( DB::raw("({$sub->toSql()}) as sub") )
->mergeBin...
What's the safest way to iterate through the keys of a Perl hash?
...h of (key, value) pairs, what is the preferred method of iterating through all the keys? I have heard that using each may in some way have unintended side effects. So, is that true, and is one of the two following methods best, or is there a better way?
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How to represent multiple conditions in a shell if statement?
...n this particular case, the parentheses aren't even needed, because -a actually has higher precedence than -o (unlike && and || in the shell - however, inside bash [[ ... ]] conditionals, && also has higher precedence than || ). If you wanted to avoid -a and -o for maximum robustness...
How do I copy a hash in Ruby?
...at clone of a hash makes a shallow copy. That is to say:
h1 = {:a => 'foo'}
h2 = h1.clone
h1[:a] << 'bar'
p h2 # => {:a=>"foobar"}
What's happening is that the hash's references are being copied, but not the objects that the references refer to.
If you want a deep...
MySQL Conditional Insert
... AND item = 456)
In this, dual is a table with one row only (found originally in Oracle, now in mysql too). The logic is that the SELECT statement generates a single row of data with the required values, but only when the values are not already found.
Alternatively, look at the MERGE statement.
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How do I disable the security certificate check in Python requests
...erification happens only once per connection so we need to close
# all the opened adapters once we're done. Otherwise, the effects of
# verify=False persist beyond the end of this context manager.
opened_adapters.add(self.get_adapter(url))
settings = old_merge_enviro...