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How to check if a file is a valid image file?
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A lot of times the first couple chars will be a magic number for various file formats. You could check for this in addition to your exception checking above.
share
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Find an item in List by LINQ?
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If you want the index of the element, this will do it:
int index = list.Select((item, i) => new { Item = item, Index = i })
.First(x => x.Item == search).Index;
// or
var tagged = list.Select((item, i) => new { Item = item, Index = i });
int index = (from pair in tagged
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Remove Primary Key in MySQL
... an index such that it is possible to perform the equivalent of an indexed SELECT MAX(ai_col) lookup on the table to obtain the maximum column value. Typically, this is achieved by making the column the first column of some table index.
– Quassnoi
Sep 23 '13 at...
Separation of business logic and data access in django
...ActivateUserForm(forms.Form):
user_id = IntegerField(widget = UsernameSelectWidget, verbose_name="Select a user to activate")
# the username select widget is not a standard Django widget, I just made it up
def clean_user_id(self):
user_id = self.cleaned_data['user_id']
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Javascript Drag and drop for touch devices [closed]
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The fact that you have simply used a different selector does not warrant being a separate answer, but instead you should have commented on @gregpress's answer.
– bPratik
Sep 28 '12 at 23:55
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SQL Server SELECT INTO @variable?
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You cannot SELECT .. INTO .. a TABLE VARIABLE. The best you can do is create it first, then insert into it. Your 2nd snippet has to be
DECLARE @TempCustomer TABLE
(
CustomerId uniqueidentifier,
FirstName nvarchar(100),
LastNa...
Remove the cell highlight color of UITableView
I want to remove the default blue color of uitableview cell selection. I don't want any selection color there. I have not created a custom cell class. I'm customizing the cell by adding labels and buttons over it.
I tried doing:
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How do I get bit-by-bit data from an integer value in C?
...s:
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char** argv)
{
unsigned
input = 0b0111u,
n_bits = 4u,
*bits = (unsigned*)malloc(sizeof(unsigned) * n_bits),
bit = 0;
for(bit = 0; bit < n_bits; ++bit)
bits[bit] = (input >...
Generating random numbers in Objective-C
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arc4random_stir(void);
void
arc4random_addrandom(unsigned char *dat, int datlen);
DESCRIPTION
The arc4random() function uses the key stream generator employed by the arc4 cipher, which uses 8*8 8
bit S-Boxes. The S-Boxes can be in about (2**1700) states. The arc4random(...
MySQL: how to get the difference between two timestamps in seconds
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You could use the TIMEDIFF() and the TIME_TO_SEC() functions as follows:
SELECT TIME_TO_SEC(TIMEDIFF('2010-08-20 12:01:00', '2010-08-20 12:00:00')) diff;
+------+
| diff |
+------+
| 60 |
+------+
1 row in set (0.00 sec)
You could also use the UNIX_TIMESTAMP() function as @Amber suggested in a...