otn meaning

#!/bin/bash#Created by Ley on 2014-11-14#Testing the Paramtersecho "The Compleate list is%s\n" "$$"echo "The Compleate list is%s\n" "$!"echo "The Compleate list is%s\n" "$?"echo "The Compleate list is%s\n" "$*"echo "The Compleate list is%s\n" "[Email protected]"echo "The Compleate list is%s\n" "$#"echo "The Compleate list is%s\n" "$ $"echo "The Compleate list is%s\n" "$"echo "The Compleate list is%s\n" "$ $"the meaning of shell variable $#,[email prot

Original URL: http://www.cnblogs.com/fhefh/archive/2011/04/15/2017613.htmlThe meaning of shell variable $#,[email protected],$0,$1,$2 in Linux is explained:Variable Description:$$The PID of the shell itself (ProcessID)$!PID of the Shell's last running background process$?End code of the last Run command (return value)$-Flag at a glance using the SET command$*All parameter lists. such as "$*" in the Case of "" ", in the form of" $ $ ... $n "output all

meaning. In the memory management of the operating system, there is a kind of important algorithm is the memory page replacement algorithm (including FIFO,LRU,LFU and so on several common page substitution algorithm). In fact, the core idea of the cache algorithm and the memory page replacement algorithm is the same: it is to design a principle to update and access the elements in a given space of limited size. The following is the core idea of the L

Linux Medium Variable $#,[email protected],$0,$1,$2,$*,$$,$? the meaningLet's start by writing a simple script that will explain the meaning of each variable after execution.The script reads as follows:[email protected] ~]# cat Test.txt#!/bin/bashecho "number:$#" echo "Scname:$0" echo "First:" echo "Second:$2" echo " Argume:[email protected] "echo" Show Parm list:$* "echo" Show Process id:$$ "echo" Show Precomm stat: $? "Save Exit Execute script[[Emai

The meaning of permissions (R, W, x) in Linux for directories and filesFirst, the significance of the permissions for the directory1, the first thing to understand is that the main content of the directory is to record the list of file names and sub-directories, rather than the place where the data is actually stored.2. R permissions: Having this permission means that the list of directory structures can be read, that is, you can view the file name an

each time the internal method is called, the method is preceded by self.Class MyClass:def __init__ (self):Passdef func1 (self):# do somethingPrint (' a ') #for exampleSelf.common_func ()def func2 (self):# do somethingSelf.common_func ()def common_func (self):PassThe meaning of self in Pythonwhen I first started to learn Python's class writing, I found it very troublesome, why we need to call when the definition is not needed, why not internal simplifi

Http://blog.sina.com.cn/s/blog_621f1e120100rj21.htmlThis is a very important part of JavaScript development, but many people feel that this is an elusive thing. To really understand the functional mechanisms of JavaScript, it is necessary to figure out what this is all about.Functions are called in different ways, this meaning is also different. There are seven ways to call functions in the JavaScript language:First: Call methodvar obj = {Method:funct

I'd like to use Ajax for all the usual code like this:But what is the meaning of void (0) here?In JavaScript, Void is an operator that specifies that an expression is evaluated but does not return a value.The void operator uses the following format:1. javascript:void (expression)2. Javascript:void expressionExpression is a standard of Javascript to evaluate. Parentheses on the outside of the expression are optional, but writing is a good habit. (Imple

the method, do not let the inheriting class change its meaning (do not allow subclasses to overwrite); allow the compiler to call this method as an inline method. Refer to the following example:public class test4{private final int li_int=0;Public final int Pub_fi_mod () {return li_int;}Protected final int pro_fi_mod () {return li_int;}Private final int pri_fi_mod () {return li_int;}private int Pri_mod () {return li_int;}}public class Test5 extends te

As a web front-end developer, accurate understanding of the meaning and compatibility of each CSS selector can be the first step in the advanced!CSS selectors can be divided into five categories: element selectors, relationship selectors, property selectors, pseudo-class selectors, and pseudo-object selectors.One, Element selectorThere are 4 element selectors:Second, the relationship selectorThere are 4 relationship selectors:Third, attribute selector

All options are optional and the following is a brief description of each option1.asyncThe default is true, which is the request for an asynchronous request, which is the meaning of Ajax presence. However, you can also set this parameter to False to implement a synchronous request. (The sync request will lock the browser until the request is complete before you can perform other actions)2.bforeSend (XHR)This method is used to modify the XMLHttpRequest

, enter the memory pressure phase.NET.IPV4.TCP_MEM[2]: Above this value, TCP refuses to allocate the socket.The above-mentioned memory units are pages, not bytes. A reference to the optimized value is: 786432 1048576 1572864 $/proc/sys/net/core/netdev_max_backlog Enter the maximum device queue for the package. The default is 300, which is too low for heavy-duty servers to be adjusted to. $/proc/sys/net/core/somaxconn The default parameter of Listen (), the maximum number of pending requests. T

FFT is a high-speed algorithm for discrete Fourier transform, which can transform a signalto the frequency domain. Some signals are very unsightly in the time domain, but asWhen the fruit is transformed into the frequency domain, it is very easy to see the features. That's a lot of signals.Analyze the reason of using FFT transform. In addition, the FFT enables the spectrum of a signal to beExtracted, which is often used in spectral analysis.Although very many people know what the FFT is, what ca

1. Return results on judge and possible problems, solutionsContent Source: http://acm.tju.edu.cn/toj/faq.html Q:What is the meaning of the judge ' s reply XXXXX?A:here is a list of the judge ' s replies and their meaning: Received : The judge system has Received your solution, usually you just need to wait a minute and your solution would be judged. Receive the procedure, waits for the judgment question t

Turn from: http://blog.chinaunix.net/uid-22018363-id-407691.html 1.linux the meaning of each folder: /bin: is a binary abbreviation that contains the commands needed to boot the system and common commands that ordinary users can use /lib: A shared library of programs and core modules under the root file system directory, which holds the root file system program Run the shared files that you want. These files contain code that can be shared by m

Slab literally meant to be divided into thick plates/slates, similar to the meaning of the Buddy algorithm (page can be in accordance with the power of 2 to form an element, can also be separated, just like a small partner, buddy algorithm because of "when the time to disperse" this performance and get the name); Slab meaning is to put a chunk of space, Break down into small chunks of space. Slab The specif

in fact to understand the meaning of 2>1, first of all should know that Linux has three kinds of standard input and output, respectively, Stdin,stdout,stderr, the corresponding number is 0,1,2. STDIN is the standard input, the default from the keyboard to read information; stdout is the standard output, the output output to the terminal by default, that is, the monitor and so on; stderr is the standard error message and is displayed on the terminal by

Turn from: http://www.cnblogs.com/zhubaoxu/archive/2008/03/17/1109315.html Although often write Ajax aspects of things, but rarely to specifically understand the XMLHttpRequest status of the meaning of each value, but in the use of Google, the following will be others have summarized the reprint, learning to learn. The status of the XMLHttpRequest object represents the state of the current HTTP request, is a long integer data, and now describes what

public int getId () { return ID; } public void setId (int id) { This.id = ID; } Public String GetName () { return name; } public void SetName (String name) { THIS.name = name; } } Through bidirectional Association, the concrete Mapperby look below: the @OneToOne here (mappedby= "wife") wife refers to Hudson's variable wife, which cannot be written casually. 1, on the meaning of Mappedby : a) only onetoone,onetomany,manytomany on the Mappedby att

the meaning of 1.Promise Promise is a solution to asynchronous programming that is more logical and powerful than traditional solutions (callback functions and events). The so-called promise is simply a container that holds the result of an event (usually an asynchronous operation) that will end in a future. Syntactically, promise is an object from which you can get messages for asynchronous operations. The Promise object has the following 2 features