0 apr meaning

Excerpt from: Abs_guide: http://www.tldp.org/LDP/abs/abs-guide.pdf The 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

Tags: number let [email protected] syn ber guide div lsp harExcerpt from: Abs_guide: http://www.tldp.org/LDP/abs/abs-guide.pdf The 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 usi

meaning of void (0) in JavaScriptOverviewThe void operator executes the statement passed to it, and then returns undefined. Grammarvoid expressionThe void operator is usually used only to get The original value of the undefined, usually with void (0) (equivalent to void 0 ). Why don't we just use undefined ? Undefi

JavaScript statement exceeds 80 characters, it is recommended that you wrap the operator or comma after the line.document.getElementById ("demo"). InnerHTML = "Hello runoob. ";2.8 Naming conventionsIn general, many code language naming conventions are similar, for example: Variables and functions are identified by the small hump method, that is, except for the first word, the first letter of the word is capitalized ( lowercamelcase) Global variable is uppercase (uppercase )

The 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 parameters.[Email protected]A

Transferred from: 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

the form "$n".$#Number of arguments added to the shellThe file name of the shell itself$1~ $nEach parameter value added to the shell. $ $ is the 1th parameter, and the $ = is the 2nd parameter ....Example:1 #!/bin/bash2 #3 printf"The complete list is %s\n""$$"4 printf"The complete list is %s\n""$!"5 printf"The complete list is %s\n""$?"6 printf"The complete list is %s\n""$*"7 printf"The complete list is %s\n" "[emailprotected]"8 printf"The complete list is %s\n""$#"9 printf"The complete list is

In JavaScript, Void is an operator that specifies that an expression is evaluated but does not return a value. The code that I want to use for Ajax is common: Copy Code code as follows: But what does void (0) mean here? void operator usage format is as follows: 1. javascript:void (expression) 2. Javascript:void expression Expression is an expression of the Javascript standard to compute. The parentheses on the outer side

still gains control of the CPU and may be replaced by another thread to gain control of the CPU. This is also what we often write in cycle Thread.Sleep (0), because this gives other threads such as the paint thread the power to gain control of the CPU, so that the interface will not feign death there.In addition, although it is mentioned above that "unless it itself abandons the CPU, it will completely occupy the CPU", but this behavior is still cons

In the _c++ primer_ dynamic array, it is legal to allocate an empty array dynamically.size_t n = get_size();int* p = new int[n];for(int* q = p; q != p + n; ++q)char arr[0];//错误char cp = new char[0];When we use new to allocate an array of size 0, new returns a valid non-null pointer. This pointer is guaranteed to be different from any other pointers returned by ne

javascript:void (0) meaningThe key in Javascript:void (0) is the Void keyword, which is a very important keyword in JavaScript, which specifies that an expression is evaluated but does not return a value.In the following example, the user clicks the link and displays a warning message, but does not renege on any value:In the following instance, because void specifies to evaluate an expression but does not r

From rookie tutorialThe key in Javascript:void (0) is the Void keyword, which is a very important keyword in JavaScript, which specifies that an expression is evaluated but does not return a value.void () simply means that no value is returned, but the expression inside the parentheses is still to be run, as　　The difference between href= "#" and href= "javascript:void (0)"# contains a location information,

: $?"Execution results[@jihite]$ sh del.sh 1 2 3number:3scname:del.shfirst:1second:2argume:1 2 3show parm list:1 2 3show process Id:21057show p Recomm stat:0Example Two#!/bin/SHNum=$ #name=$0Echo "Number : $num"Echo "scname: $name"Echo$0Echo$1Echo$2 for((i=0; i)) Do Echo "$i" DoneEcho "Argume:[email protected]" forKeyinch[email protected] Do Echo$key DoneEcho "-----------------" forKeyinch "[email protected]" Do Echo$key DoneEcho "-----------

# Touch Variable # VI variable script content is as follows:#!/bin/shecho "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 gives script Execute permission# chmod +x Variable Execute script #./variable aa bb number:2 scname:./variable first:aa second:bb argume:aa bb show Parm LIST:AA BB show process ID: 24544 Show P

Parameter description1:$# indicates the number of arguments passed into the script2:$* indicates the execution of a script passed in the parameter list3:$$ represents the Process ID4:[email protected] means that the execution script passes all parameters5:$0 represents the execution script name6:$1 represents the first parameter7:$2 represents the second argument8:$? Indicates script execution status 0 Norm

The meaning of the shell variable $ #, $ @, $0, $1, $2 in linuxVariable description $ shell's PID (processID) $! Background ProcessID $? End code of the last command (Return Value) $-Flag list Set using the Set command $ * List of all parameters. For example, if "$ *" is enclosed by "$1 $2 $3... $ n", all parameters are output. $ @ List of all parameters. For example, if you use "$ @" and "enclose it with"

$# is the number of arguments passed to the script. $ is the name of the script itself. $ is the first parameter passed to the shell script, and the second argument that is passed to the shell script is [email protected] is a list of all the parameters passed to the script $*is to display all parameters passed to the script in a single string, unlike positional variables, which can be more than 9 $$ is the current process ID number for the script to run? is to display the exit status of the last

Variable Description:$$ Shell本身的PID（ProcessID） $! Shell最后运行的后台Process的PID $? 最后运行的命令的结束代码（返回值） $- 使用Set命令设定的Flag一览 $* 所有参数列表。如"$*"用「"」括起来的情况、以"$1 $2 … $n"的形式输出所有参数。 [emailprotected] 所有参数列表。如"[emailprotected]"用「"」括起来的情况、以"$1" "$2" … "$n" 的形式输出所有参数。 $# 添加到Shell的参数个数 $0 Shell本身的文件名 $1～$n Example:#!/bin/bash#printf "The complete list is%s\n" "$$"printf "The complete list is%s\n" "$!"printf

- Echo "Arg # $index = $arg" -Let"index+=1" - Done - in Echo "-----------------------" - toindex=1 + - Echo "get args by \ "\$*\":" the * forArginch "$*" $ DoPanax Notoginseng Echo "Arg # $index = $arg" - Done the + Echo "-----------------------"Output Result:$SHShow.SHDont"worry be"Happy----------------------PID: $$12897option numbers: $#3 LastReturn: $?0All parameters: $*dont worry be happyall parameters: [email protected] dont worry be happyfileName: $0Show.SH1st param: $1dont2nd pa

let's start by writing a simple script that will explain the meaning of each variable after execution .# Touch Variable# VI VariableThe script reads as follows:#!/bin/shecho "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 Exitassigning script Execution Permissions# chmod +x variableEx