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How to remove last n characters from every element in the R vector
... an example of what I would do. I hope it's what you're looking for.
char_array = c("foo_bar","bar_foo","apple","beer")
a = data.frame("data"=char_array,"data2"=1:4)
a$data = substr(a$data,1,nchar(a$data)-3)
a should now contain:
data data2
1 foo_ 1
2 bar_ 2
3 ap 3
4 b 4
...
Why does GCC generate such radically different assembly for nearly the same C code?
... why they are so different, first we must understand how GCC optimizes fast_trunc_one().
Believe it or not, fast_trunc_one() is being optimized to this:
int fast_trunc_one(int i) {
int mantissa, exponent;
mantissa = (i & 0x07fffff) | 0x800000;
exponent = 150 - ((i >> 23) &...
Simple C example of doing an HTTP POST and consuming the response
...es have \r\n at the end.
A URL has the form of http://host:port/path?query_string
There are two main ways of submitting a request to a website:
GET: The query string is optional but, if specified, must be reasonably short. Because of this the header could just be the GET command and nothing else...
Get generated id after insert
...LiteDatabase().insert("user", "", values) ;
If query exec use select last_insert_rowid()
String sql = "INSERT INTO [user](firstName,lastName) VALUES (\"Ahmad\",\"Aghazadeh\"); select last_insert_rowid()";
DBHelper itemType =new DBHelper();// your dbHelper
c = db.rawQuery(sql, null);
if (c.move...
What does the JSLint error 'body of a for in should be wrapped in an if statement' mean?
...type. Suppose you want all arrays to have a cool new function called filter_0 that will filter zeroes out.
Array.prototype.filter_0 = function() {
var res = [];
for (var i = 0; i < this.length; i++) {
if (this[i] != 0) {
res.push(this[i]);
}
}
return r...
Best way to store date/time in mongodb
...ISODate()})
> db.test.insert({date: new Date()})
> db.test.find()
{ "_id" : ObjectId("..."), "date" : ISODate("2014-02-10T10:50:42.389Z") }
{ "_id" : ObjectId("..."), "date" : ISODate("2014-02-10T10:50:57.240Z") }
The native type supports a whole range of useful methods out of the box, which...
Can I get Memcached running on a Windows (x64) 64bit environment?
...x
http://allegiance.chi-town.com/Download.aspx?dl=Releases/MemCacheDManager_1_0_3_0.msi&rurl=MemCacheDManager.aspx
To unpack the msi:
msiexec /a Releases_MemCacheDManager_1_0_3_0.msi /qb TARGETDIR=c:\memcached
share
...
Why can I not push_back a unique_ptr into a vector?
...
You need to move the unique_ptr:
vec.push_back(std::move(ptr2x));
unique_ptr guarantees that a single unique_ptr container has ownership of the held pointer. This means that you can't make copies of a unique_ptr (because then two unique_ptrs would ...
Find the files existing in one directory but not in the other [closed]
...ted Apr 26 '16 at 12:41
Talespin_Kit
16.6k2222 gold badges8282 silver badges115115 bronze badges
answered May 28 '13 at 9:30
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NtMapViewOfSection注入 - C/C++ - 清泛网 - 专注C/C++及内核技术
...要特殊的条件比如像管理员权限或者之类的要求
#define _WIN32_WINNT 0x0400
#include <windows.h>
typedef LONG NTSTATUS, *PNTSTATUS;
#define NT_SUCCESS(Status) ((NTSTATUS)(Status) >= 0)
typedef enum _SECTION_INHERIT
{
ViewShare = 1,
ViewUnmap = 2
} SECTION_INHERIT;
...