大约有 43,000 项符合查询结果(耗时:0.0246秒) [XML]
Split comma-separated strings in a column into separate rows
... occasions, because the datatable approaches only produce tables with the "selected" columns, while dplyr produces a result with all the columns (including the ones not involved in the analysis and without having to write their names in the function).
– Ferroao
...
Creating a new directory in C
...ng a gnu extension to print the error message with printf.
void rek_mkdir(char *path) {
char *sep = strrchr(path, '/');
if(sep != NULL) {
*sep = 0;
rek_mkdir(path);
*sep = '/';
}
if(mkdir(path, 0777) && errno != EEXIST)
printf("error while try...
In C/C++ what's the simplest way to reverse the order of bits in a byte?
...
This should work:
unsigned char reverse(unsigned char b) {
b = (b & 0xF0) >> 4 | (b & 0x0F) << 4;
b = (b & 0xCC) >> 2 | (b & 0x33) << 2;
b = (b & 0xAA) >> 1 | (b & 0x55) << 1;
retu...
How to determine CPU and memory consumption from inside a process?
...hysMemUsedByMe = pmc.WorkingSetSize;
CPU currently used:
#include "TCHAR.h"
#include "pdh.h"
static PDH_HQUERY cpuQuery;
static PDH_HCOUNTER cpuTotal;
void init(){
PdhOpenQuery(NULL, NULL, &cpuQuery);
// You can also use L"\\Processor(*)\\% Processor Time" and get individual CPU...
URLEncoder not able to translate space character
...be encoded as follows:
Control names and values are escaped. Space characters are replaced
by `+'
You will have to replace it, e.g.:
System.out.println(java.net.URLEncoder.encode("Hello World", "UTF-8").replace("+", "%20"));
...
How can I split a string with a string delimiter? [duplicate]
...new[] { "is Marco and" }, StringSplitOptions.None);
If you have a single character delimiter (like for instance ,), you can reduce that to (note the single quotes):
string[] tokens = str.Split(',');
share
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...
C++ Structure Initialization
...er. And dot notation is way safer if you happen to add the same type (like char*) as one of the other members above or below in the structure, because there's no risk of swapping them.
– Gui13
Nov 16 '16 at 9:21
...
How do I grant myself admin access to a local SQL Server instance?
...he "SQL Server Configuration Manager", right click the server instance and select properties, go to the tab "Startup Parameters" and add -m.
– maets
May 5 '15 at 13:32
...
How to make my custom type to work with “range-based for loops”?
...ample of why this is useful is that your end iterator can read "check your char* to see if it points to '0'" when == with a char*. This allows a C++ range-for expression to generate optimal code when iterating over a null-terminated char* buffer.
struct null_sentinal_t {
template<class Rhs,
...
libevent+protobuf轻松搭建tcpserver - C/C++ - 清泛网 - 专注C/C++及内核技术
...:socket(),connect(),返回连接的sockfd
int create_io_channel(const char *ipaddr, int port);
2. 搭建TCP Server
下面以伪代码方式给出,错误处理省略
int main(int argc, char *argv[])
{
// 初始化
…
// event初始化
event_init();
init_server(por...