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/usr/lib/libstdc++.so.6: version `GLIBCXX_3.4.15' not found
How can I get GLIBCXX_3.4.15 in Ubuntu? I can't run some programs that I'm compiling.
19 Answers
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mongo group query how to keep fields
...h group, you can try aggregating like:
db.test.aggregate({
$group: {
_id : '$name',
name : { $first: '$name' },
age : { $first: '$age' },
sex : { $first: '$sex' },
province : { $first: '$province' },
city : { $first: '$city' },
area : { $first: '$area' },
address : { $firs...
Linq to Sql: Multiple left outer joins
...SQL:
Dim db As New ContractDataContext()
Dim query = From o In db.Orders _
Group Join v In db.Vendors _
On v.VendorNumber Equals o.VendorNumber _
Into ov = Group _
From x In ov.DefaultIfEmpty() _
Group Join s In db.Status _
On...
How to obtain the number of CPUs/cores in Linux from the command line?
...
The most portable solution I have found is the getconf command:
getconf _NPROCESSORS_ONLN
This works on both Linux and Mac OS X. Another benefit of this over some of the other approaches is that getconf has been around for a long time. Some of the older Linux machines I have to do development o...
URL rewriting with PHP
...
You can essentially do this 2 ways:
The .htaccess route with mod_rewrite
Add a file called .htaccess in your root folder, and add something like this:
RewriteEngine on
RewriteRule ^/?Some-text-goes-here/([0-9]+)$ /picture.php?id=$1
This will tell Apache to enable mod_rewrite for this ...
Create a menu Bar in WPF?
...nel>
<Menu DockPanel.Dock="Top">
<MenuItem Header="_File">
<MenuItem Header="_Open"/>
<MenuItem Header="_Close"/>
<MenuItem Header="_Save"/>
</MenuItem>
</Menu>
<StackPanel></StackPa...
How to set child process' environment variable in Makefile
...ever you can use make's export to force them to do so. Change:
test: NODE_ENV = test
to this:
test: export NODE_ENV = test
(assuming you have a sufficiently modern version of GNU make >= 3.77 ).
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...
Run a callback only if an attribute has changed in Rails
...
Rails 5.1+
class Page < ActiveRecord::Base
before_save :do_something, if: :will_save_change_to_status_id?
private
def do_something
# ...
end
end
The commit that changed ActiveRecord::Dirty is here: https://github.com/rails/rails/commit/16ae3db5a5c6a08383b974ae...
Detecting endianness programmatically in a C++ program
...e warned against by compiler. That's exactly what unions are for !
bool is_big_endian(void)
{
union {
uint32_t i;
char c[4];
} bint = {0x01020304};
return bint.c[0] == 1;
}
The principle is equivalent to the type case as suggested by others, but this is clearer - and...
How can I extract the folder path from file path in Python?
....path.split(os.path.abspath(existGDBPath))
('T:\\Data\\DBDesign', 'DBDesign_93_v141b.mdb')
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