大约有 47,000 项符合查询结果（耗时：0.0424秒） [XML]
Using semicolon (;) vs plus (+) with exec in find
...ecute multiple commands (separately for each argument),
Example:
$ find /etc/rc* -exec echo Arg: {} ';'
Arg: /etc/rc.common
Arg: /etc/rc.common~previous
Arg: /etc/rc.local
Arg: /etc/rc.netboot
All following arguments to find are taken to be arguments to the command.
The string {} is repl...
Concatenate multiple result rows of one column into one, group by another column [duplicate]
...cter, "char"), and some other types.
As isapir commented, you can add an ORDER BY clause in the aggregate call to get a sorted list - should you need that. Like:
SELECT movie, string_agg(actor, ', ' ORDER BY actor) AS actor_list
FROM tbl
GROUP BY 1;
But it's typically faster to sort rows in a...
What is Normalisation (or Normalization)?
...omalies, meaning that you have to decompose and scan individual values in order to find what you are looking for. For example, if one of the values is the string "Ford, Cadillac" as given by an earlier response, and you are looking for all the ocurrences of "Ford", you are going to have to break...
When do I need to use AtomicBoolean in Java?
...weakCompareAndSet atomically reads and conditionally writes a variable, is ordered with respect to other memory operations on that variable, but otherwise acts as an ordinary non-volatile memory operation.
compareAndSet and all other read-and-update operations such as getAndIncrement have the memo...
Apache .htaccess 禁止访问某目录方法 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...所要禁止的目录中的.htaccess文件中添加一下两行代码。
order allow,deny
deny from all
(可以把all换成某一ip地址)最简单方法，在所要禁止的目录中的.htaccess文件中添加一下两行代码。
order allow,deny
deny from all
(可以把all换成某一...
Configuring so that pip install can work from github
...on servers. This question concerns what needs to be in the github repo in order for the install to be successful.
5 Answer...
How to use timeit module
...sort really shine because it performs best when the data already partially ordered).
Here is an example of how to set up a test for sorting:
>>> import timeit
>>> setup = '''
import random
random.seed('slartibartfast')
s = [random.random() for i in range(1000)]
timsort = list.s...
Best way to randomize an array with .NET
...and I'd like to create a new Array with the same strings but in a random order.
17 Answers
...
MySQL ERROR 1045 (28000): Access denied for user 'bill'@'localhost' (using password: YES)
...connect, the server looks through the rows [of table mysql.user] in sorted order.
The server uses the first row that matches the client host name and user name.
(...)
The server uses sorting rules that order rows with the most-specific Host values first.
Literal host names [such as 'lo...
write a shell script to ssh to a remote machine and execute commands
...ript and put your linux machines IPs, usernames and password in respective order. After that run that script. Thats it ! This script will install VLC in all systems.
#!/bin/bash
SCRIPT="cd Desktop; pwd; echo -e 'PASSWORD' | sudo -S apt-get install vlc"
HOSTS=("192.168.1.121" "192.168.1.122" "192.1...