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What does -D_XOPEN_SOURCE do/mean?
... the gcc man page, but did not find this specific option. I did find XOPEN_SOURCE , but there was little explanation of what it does.
...
detach all packages while working in R
...h()[pos]’. This can
be an unquoted name or a character string but _not_ a
character vector. If a number is supplied this is taken as
‘pos’.
So we need to repeatedly call detach() once per element of pkg. There are a couple of other arguments we need to specify to get thi...
How do I use prepared statements in SQlite in Android?
... Below are some examples:
Create a table
String sql = "CREATE TABLE table_name (column_1 INTEGER PRIMARY KEY, column_2 TEXT)";
SQLiteStatement stmt = db.compileStatement(sql);
stmt.execute();
The execute() method does not return a value so it is appropriate to use with CREATE and DROP but not in...
BLE 低功耗蓝牙调试助手：扫描、连接、读写、订阅通知（附 .aia 源码） · ...
...会变，序号容易对不上。
global 设备地址表 = []
when 按钮_扫描.Click() {
设备地址表 = []
低功耗蓝牙1.StartScanning()
}
when 低功耗蓝牙1.DeviceFound() {
var 行列表 = []
设备地址表 = []
foreach 项 in split(低功耗蓝牙1.DeviceList, ",") {
v...
Javascript regex returning true.. then false.. then true.. etc [duplicate]
...
/^[^-_]([a-z0-9-_]{4,20})[^-_]$/gi;
You're using a g (global) RegExp. In JavaScript, global regexen have state: you call them (with exec, test etc.) the first time, you get the first match in a given string. Call them again and ...
Error handling in Bash
...up() {
rm -f "${tempfiles[@]}"
}
trap cleanup 0
error() {
local parent_lineno="$1"
local message="$2"
local code="${3:-1}"
if [[ -n "$message" ]] ; then
echo "Error on or near line ${parent_lineno}: ${message}; exiting with status ${code}"
else
echo "Error on or near line ${pare...
'id' is a bad variable name in Python
...() is a fundamental built-in:
Help on built-in function id in module
__builtin__:
id(...)
id(object) -> integer
Return the identity of an object. This is guaranteed to be unique among
simultaneously existing objects. (Hint: it's the object's memory
address.)
In g...
How to use the TextWatcher class in Android?
...gered again, starting an infinite loop. You should then add like a boolean _ignore property which prevent the infinite loop.
Exemple:
new TextWatcher() {
boolean _ignore = false; // indicates if the change was made by the TextWatcher itself.
@Override
public void afterTextC...
Simplest/Cleanest way to implement singleton in JavaScript?
... pattern:
short form
var Foo = function () {
"use strict";
if (Foo._instance) {
//this allows the constructor to be called multiple times
//and refer to the same instance. Another option is to
//throw an error.
return Foo._instance;
}
Foo._instance = t...
Pass data to layout that are common to all pages
...{
var model = someList;
return PartialView("~/Views/Shared/_maPartialView.cshtml", model);
}
You just need to put your model begining of the partial view '_maPartialView.cshtml' that you created
@model List<WhatEverYourObjeIs>
Then you can use data in the model in that...