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Introduction to RedShift NVL

RedShift NVL expression will return the first expression value from the argument list which was not null, NVL function will return the empty result when our argument contains all null values. NVL function is equivalent to the coalesce function while using a big query, at the time of migrating our code from redshift we need to rewrite the function in a big query. The function is identical to the coalesce function, NVL expression is the synonym of coalesce function or expression. We can say that NVL and coalesce expressions are synonyms to each other.

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Syntax of RedShift NVL

Below is the syntax of NVL expression in RedShift:

NVL (expression1, expression2,…., expressionN);

Select NVL (column_name1, column_name2) From table_name;

Parameter description syntax of NVL function:

Expression1 to expressionN: This is defined as any expression which we have using with NVL function in redshift. For multiple values, the NVL function will return a first not-null value in the result.

Table name: This is nothing but the name of the table which was we have using with the NVL function to retrieve the first not-null value.

Select: Select is used to fetch data from a table by using the NVL function in redshift. Using column name with NVL function we can retrieve data from a table which was we have used in our query.

Argument 1 to Argument N: Argument is nothing but an integer value that we have passing with NVL function in redshift. If suppose we have passing three-argument with NVL function and if the first argument contains null value then NVL function will return next not null value.

Column name: This is the column name of the table which was we have used with NVL function. If we want to fetch data from a table using the NVL function in redshift then we need to pass column name.

NVL: NVL is the function or expression name which returns the first not-null value as a result. NVL function is the identical to coalescing function in redshift.

How NVL works in RedShift?

RedShift NVL function will evaluate values or arguments from left to right to find the not-null value or argument.

The function is used to return the first, not null value from the table column or from the list of arguments which was we have used in the query.

At the time of finding the first, not null value, the NVL function will not evaluate the remaining argument from the column or argument list which was used in our query.

NVL function will not treat zero as a not null value, zero is considered as valid, not null value with NVL in redshift.

The below example shows that the NVL function will not treat zero as a not null value, zero is considering as valid, not null value is as follows.

Code:

Select NVL (NULL, 0, NULL, 10, 20);

Output:

In the above example, we have used the argument list as (NULL, 0, NULL, 10, 20). In the first argument, we have used null value and in the second argument, we have used zero value. So NVL function will return the result as zero which was not null because the NVL function is considering zero as a not a null value.

We can also use order by and group by condition with NVL function to extract the data from a table.

As we know that NVL function is identical with coalescing function in redshift. NVL function will return the null values if our argument list contains all the null values.

NVL function will not evaluate all lists when it has found the not null value from the argument list. If suppose our argument list contains five numbers like (NULL, NULL, 10, NULL, 50).

In the above list, we can see that we have provided 10 values which were not null in the third position so the result of this argument using the NVL function is 10. After retrieving the result as 10 it will not evaluate the other argument list.

The default column name of NVL expression in redshift coalesces. At the time of executing the NVL function on the argument list it will show the output column name as coalesce.

The below example shows the column name of NVL expression in RedShift is coalesce.

Code:

Select NVL (15, 20, NULL, 25, NULL);

Output:

In the above example, we can see that we have used NVL expression with argument list but in result, it will showing column name as coalesce.

Examples of RedShift NVL

Given below are the examples mentioned:

Example #1

NVL function using a single value as the argument list.

The below example shows that the NVL function using a single value as argument list is as follows. We have using 20 values as an argument list with the NVL function.

Code:

Select NVL (20);

Example #2

NVL function using multiple values as the argument list.

The below example shows that NVL functions using multiple values as argument lists is as follows. We have used (20, 25, 30, 35, 40) values as argument lists with NVL function.

Code:

Select NVL (20, 25, 30, 35, 40);

Output:

Example #3

NVL function using null value as the argument list.

The below example shows that the NVL function using all null values as argument list is as follows. We have used (NULL, NULL, NULL, NULL) values as argument list with NVL function.

Code:

Select NVL (NULL, NULL, NULL, NULL);

Output:

Example #4

NVL function using two-column as the argument list.

Below example shows that NVL function using two-column as argument list are as follows. We have using date1 and date2 columns as argument lists with NVL functions.

Code:

Select nvl (date1, date2) from nvl_test;

Output:

Example #5

NVL function using the single-column as the argument list.

The below example shows that the NVL function using a single column as an argument list is as follows. We have using the date1 column as an argument list with the NVL function.

Code:

Select nvl (date1, date2) from nvl_test;

Output:

Conclusion

RedShift NVL function is very useful and important to find the first not null value from column or argument list. NVL function is identical to the coalesce function in redshift. If suppose all column value contains the not null value then NVL function will return the empty result.

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How Does Wait Function Work In Lua

Introduction to Lua wait.

The Lua wait is a function used when multiple processes simultaneously and want the primary process to stop for a given time. It is a method useful for stopping or delays the parent process until the child process is not working completely. It helps to reduce complications of the multiple processes at a time and work orderly. This function helps to stop or sleep parent thread for a minute, second, and millisecond and child thread within time. It helps to stop the parent thread for the child thread procedure and start the parent thread process after finish the child thread process. This method gives sleep time to work multiple thread procedures together without any critical issues.

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Syntax of Lua wait

Given below is the syntax of Lua wait:

function wait(unit of time) Lua source codes for wait function… end wait(required time)

Explanation:

The “wait (unit of time)” is a method used to give the unit of time like a minute, second, and millisecond to stop the working procedure.

Example:

Code:

function wait ( millisecond ) end

The source code assigns the time to thread procedure for multiple operations.

The wait function delays the time in the millisecond using syntax example.

The wait (required time) is a function using forgiven time as per the user’s requirements.

Example:

wait( 1 )

The wait function is to stop the time to parent thread for one (1) millisecond.

How does wait Function Work in Lua?

Step 1: Lua programming IDE Environmental Setup.

The Lua text editor, Lua compiler, and Lua interpreter install in your computer as per the operating system and software version.

Or

It does not have software; then, you can use Lua Online IDEs for coding and start Lua programming.

Step 2: Create the Lua File.

The Lua file creates with the .lua extension and writes a source code.

Step 3: Creates the wait function with the time unit argument.

Code:

function wait(millisecond) write a code for the Lua wait function… end

Step 4: Create a variable with the operating system time.

Code:

local ostime_vrbl = os.time()

Step 5: Print the running time of the system.

print( "timing of Lua wait function: ", ostime_vrbl );

Step 6: Create a Lua wait method with the given time.

Code:

wait(0.5);

Combine the procedure of the Lua waits for demo example.

Code:

function wait(millisecond) local ostime_vrbl = os.time() print( "timing of Lua wait function: ", ostime_vrbl ); end wait(0.5); Examples of Lua wait

Given below are the examples mentioned:

Example #1

The Lua wait function with millisecond example and output.

Code:

function wait(millisecond) local ostime_vrbl = os.time() + millisecond print( "timing of Lua wait function: ", ostime_vrbl ); end wait(0.5); wait(1); wait(1.5); wait(2); wait(2.5); wait(3);

Output:

The example is using a millisecond unit of time for function.

Example #2

Function with the second example and output.

Code:

function wait(second) local ostime_vrbl = os.time() + second print( "timing of Lua wait function: ", ostime_vrbl ); end wait(1); wait(1.5); wait(2); wait(3); wait(4); wait(5);

Output:

Explanation:

The example is using the second unit of time for function.

Example #3

Function with millisecond and second Example and output.

Code:

function wait(second, millisecond) local ostime_vrbl = os.time() + second, millisecond print( "timing of Lua wait function: ", ostime_vrbl ); end wait(1, 2); wait(1, 0.5); wait(2, 1); wait(3, 0.7); wait(4); wait(5, 0);

Output:

Explanation:

The example is using the second and millisecond unit of time for function.

If we use two units of time, then the user either uses both time units or a single time unit.

Example #4

Lua wait function with “do while” condition example and output.

Code:

function wait(second, millisecond) local ostime_vrbl = os.time() + second, millisecond; while os.time() < ostime_vrbl do end print( "timing of Lua wait function: ", ostime_vrbl ); end wait(1, 2); wait(1, 0.5); wait(2, 1); wait(3, 0.7); wait(4); wait(5, 0);

Output:

Explanation:

The example is using the second and millisecond unit of time for the Lua wait function.

The Lua wait function is using the “do while” condition for comparison time.

If the operating system time is less than the given time, then the wait function works.

Example #5

Code:

function wait(second, millisecond) local ostime_vrbl = os.time() +  millisecond; repeat until os.time() < ostime_vrbl print("timing of Lua wait function: ", ostime_vrbl); end wait(1, 2); wait(1, 0.5); wait(2, 1); wait(3, 0.7); wait(4, 1); wait(5, 0);

Output:

Explanation:

The example is using the second and millisecond unit of time for the Lua wait function.

It is used milliseconds to return the time value.

This function is using the “repeat” condition for comparison time.

If the operating system time is less than the given time, then the wait function works.

Example #6

Function with compares time and variable example and output.

Code:

function wait(second, millisecond) local ostime_vrbl = os.time() + second, millisecond; print( "timing of Lua wait function: ", ostime_vrbl ); end wait(1, 2); wait(1, 0.5); wait(2, 1); wait(3, 0.7); wait(4); wait(5, 0);

Output:

Explanation:

The example is using the second and millisecond unit of time for the Lua wait function.

The Lua wait function is using the “do while” condition for comparison time.

If the operating system time is greater than the given time, then the wait function works.

Example #7

Lua waits with zero second example and output.

Code:

function wait(second, millisecond) local ostime_vrbl = os.time() + second, millisecond; while os.time() < ostime_vrbl do end print( "timing of Lua wait function: ", ostime_vrbl ); end wait(0);

Output:

Explanation:

The example is using the second and millisecond unit of time for the function.

The wait method does not use empty or nil values until an error occurred.

The user must give zero (0), millisecond, second, or minute inside for the wait method.

Conclusion

The Lua wait function helps to avoid complications of multiple operations. This function makes easy, elegant, and sophisticated applications. This function makes a fast, error-free application.

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How Does Concurrency Work In Go Language?

Introduction to Golang Concurrency

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Syntax of Golang Concurrency

Below is a simple syntax for the concurrency of the go language, We can explain the below go, here in the below first we have written a function with the name name-of-function and this function contains several expressions. These expressions can be any calculation and some other tasks. Now suppose we wanted to run expression 1, expression 2, and expression 3 at the same time we want to execute the expression, or very simply we want to concurrently execute them. So we can use the sleep and this will allow us to control execute them at the same time.

Please see the below syntax for a better understanding.

func name-of-function(){ } go name-of-function() How Does Concurrency Work in Go language?

Before going to discuss the working of the concurrency in go language let us understand the basic concept and uses of the concurrency in the Go language. You have seen YouTube video, if you will see there are always two things that will be happening at one time one is the playing of the video and another is the buffering of the video. This means even you pause the video buffering happens, and after that even inter gone which means in offline mode also you will be able to play the video. This all happening because of the concurrency, which is allowing the application to run at one time, and at the same time, it allows us to buffer the video for capturing the video for offline mode. All these things are happening just because of the concurrency. So basically in concurrency first one particular task will run and in the meanwhile, sleep function will be called which will give space to run another task. We have already discussed the goroutine, basically, it is a call between two goroutines, go language there will be multi goroutine and there will be one main goroutine, every goroutine will fall under the main goroutine and if the main goroutine will terminate then other all go routine all be terminated. We can discuss point to point to the working of the concurrency of the.

Concurrency allows you to use goroutine which is blockers, you know once a go routine gets called it will block for execution of others.

Hence with the help of sleep, we will be able to call concurrent goroutine.

Every goroutine belongs to the main goroutine in go language and if the main goroutine will be terminated then all other goroutines will also terminate.

Examples to Implement Golang Concurrency

In the below we have given three examples, these examples explain the way of working of the concurrency. If we wanted to execute this code then we can take the example and pass them on any file and run the command go run chúng tôi and we can see the output.

Example #1

Below is a simple example where we are calling a function show and this call continuously prints the data, but here we are not printing data in the concurrency, which means we are printing one by one.

Code:

package main import "fmt" func show(name string) { for i := 0; i< 6; i++ { fmt.Println(name) } } func main() { go show("Ajay") show("Ranjan") }

Example #2

In the below example we have a function called the show and that function is defined with the help of the go keyword and then this show function called, inside the function definition we have written the logic to print the param passed to the function show and each time when it get called it will be print the param. Now the question is we want to execute then concurrently which means together execution of these two go show(“Ajay”) and show(“Ranjan”). So we have written a sleep function inside the show definition, it will allow two simultaneous calls to the function for executions. See the example output first it is printing Ajay and then it printing Ranjan, this way it will keep printing both the names are getting a chance to print.

Code:

package main import ( "fmt" "time" ) func show(name string) { for i := 0; i< 6; i++ { time.Sleep(1 * time.Second) fmt.Println(name) } } func main() { go show("Ajay") show("Ranjan") }

Output:

Example #3

Code:

package main import ( "fmt" "time" ) func main() { fmt.Println("Hello , friends how are you") go func() { fmt.Println("How are you doing ") }() time.Sleep(2 * time.Second) fmt.Println("We have done with the discussion") }

Output:

Conclusion

From this tutorial we learned the basic concept of concurrency in the Go language, we learned the syntax and the working way of the concurrency in the Go language. We also focus on some of the examples with their explanation which revealed the working of the concurrency in go language.

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How Sort() Algorithm Function Work In C++

Introduction to C++ sort()

The sort() function in C++ sorts a number of elements or a list of elements within the first to last elements in an ascending or descending order. This function executes the sorting operation within the specified list or range, starting with the first element and ending with the last element. The sort function takes in two parameters as arguments and returns the result of sorting. Comparing the elements is the main operation. There can be exceptions in case the elements that are being compared encounter any exceptions. The most common ways to sort are in either an ascending order or a descending order.

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Syntax and parameters:

The standard syntax for the sort function includes of sort keyword and two parameters. The return output will be the result of the sort operation.

void sort(RIt first, RIt last);

The parameters implemented in the above syntax are RandomIt, first and last.

Here the first and last are the range between whose sorting is to be done; the first notifies the first element of the list, while the last denotes the last element.

How sort() Algorithm Function work in C++?

The basic method by which the sorting algorithm works is based on comparison.

The sorting function attempts to compare each and every element of the list.

The comparison works in a way as comparing the first element with the second element, followed by the second and third, and so on. Here the comparison operator “<” is widely used.

So, simply speaking, the sort function at a time picks two values or elements of a list, then compare these two values to identify smaller and bigger value and arrange them in a form, ascending or descending, whichever is required.

Examples of C++ sort()

We will have a list of values, which will be unsorted and not in any order, and we will aim to correct the list by implementing the sort function.

Example #1

Our first example takes in an array of number values, unsorted, and we will implement the sort, and the output will be a list of values in a sorted format.

Code:

using namespace std; int main() { int arr1[] = {99,91,94,96}; int n = sizeof(arr1)/sizeof(arr1[0]); sort(arr1, arr1+n); cout << “n List of Array after sorting is: “; for (int i = 0; i < n; ++i) cout << arr1[i] << ” “; return 0; }

Explanation:

We have our system files and namespace, followed by initializing the main code. Then we have our first array variable of integer type, which holds a list of four numbers totally unsorted, following no order.

Then we have another integer variable followed by the sort function. We then print s statement, which then comes in our for statement, which will pick and print the numbers in a sorted format.

Upon successful execution, the output of the program will be a statement and a list of four numbers in a sorted format.

Output:

As explained and expected, the program generates an output statement followed by the corrected and sorted list of numbers. The sorting operation is performed in ascending order.

Example #2

Code:

using namespace std; void show(int a[]) { for(int b = 0; b < 10; ++b) cout << a[b] << ” “; } int main() { int a[10]= {3,4,1,0,5,7,8,6,9}; cout << “n This is the unsorted list: “; show(a); sort(a, a+10); cout << “nn Here’s the output of sort operation:: “; show(a); return 0; }

Explanation:

Started with required system files followed by declaring the login for the program. Then we have our main block of code, where we have an array with integer values followed by a print statement.

Then we have our sort function and parameter values passed, followed by the print statement and the final output.

The expected output is two statements, which include a list of the unsorted array and another list which is the output of the sorting operation.

Output:

Our code executed as expected, and the output is proper.

Example #3

Code:

int main() { std::cout << ‘n’; std::cout << “Sorting done with simple < operator: “; std::cout << ‘n’; std::sort(list.begin(), list.end()); for (auto a : list) { std::cout << a << “  “; } std::cout << ‘n’; std::cout << “n This is output of sorting using custom function: “; std::cout << ‘n’; struct { bool operator()(int a, int b) const { return a < b; } } customLess; std::sort(list.begin(), list.end(), customLess); for (auto a : list) { std::cout << a << ” “; } std::cout << ‘n’; }

Explanation:

Like the earlier example, we begin with the required system files and a main block. Then we have our array of values, followed by a few lines of code for output, where we first print the sorted list as a result of our sort operation. Then within our second method, we have a custom function, which creates a struct and passes the values.

Then we have our sort function, which starts with begin, then the end, and the custom function.

Output:

As expected, the output of the code is that the sorting has been done in two different formats using two methods.

Conclusion

In C++, we use the sort() function to sort a list of values. This function allows us to perform sorting in either ascending or descending order. We saw a few methods and ways to implement the sort function.

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How Does Subroutine Function Work In Perl?

Introduction to Perl Subroutine

Perl Subroutine is used to reusable code using a subroutine that we can use code, again and again, there is no need to repeatedly write the code. We can create our own functions it is called a subroutine. Subroutines are very important to improve the code reusability. It is also used to improve the code readability, using subroutine we can improve the code readability of our program. To use subroutine in our program we need to define or need to create it first, after creating then we call a subroutine in our code.

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Syntax of Perl Subroutine

1. Defining a subroutine: To use subroutine in our program we need to create it first and then we need to call in our program. Below syntax shows define or create a subroutine in perl are as follows.

Syntax:

Sub subroutine_name  -- Name of subroutine that we have defining. { Statements;    -- Statement to be used in body of the subroutine. Return; }

2. Calling Subroutine: In perl we calling subroutine by passing a list of arguments. Below syntax shows calling a subroutine in perl are as follows.

Syntax:

subroutine_name (arguments_list); -- List of arguments which was used with subroutine. Parameters of Perl Subroutine

Below is the parameter description syntax of the subroutine in Perl is as follows.

Subroutine Name: It is very important while creating subroutine. We have defined any name to subroutine while creating the same. The subroutine name is the name that we have defined to the subroutine.

Statement: The statement is defined as a block or body of the code of subroutine. This code is written under the body of the subroutine. We can define one or more statement in the body of the subroutines.

Return: This is defined as the return an argument to its calling functions or subroutines. We can return no of arguments to the calling function in perl.

Argument List: This is defined as arguments which we have used at the time of calling a subroutine in Perl. We have pass one or more arguments at the time of calling a subroutine in Perl.

How Does Subroutine Function work in Perl?

Below is the working of the subroutine is as follows. Below is the important use of subroutine in perl.

Reusability of code.

Improve the code readability.

The subroutine is used to improve code reusability. If we want to take input from the user multiple times at the same time we have creating subroutine and then we call the subroutine in our program whenever we need it.

We can improve the code reusability while using the subroutine in our program. After using subroutine there is no need to write it again and again.

We can create our own functions it is called subroutines.

To use subroutine in our program we need to define or need to create it first, after creating then we call the same in our code.

It is used to reusability of code using subroutine we can use code, again and again, there is no need to write the code again and again.

It is also used to improve the code readability, using subroutine in perl we can improve the code readability of our program.

Subroutines is very important and useful to improve code reusability and readability.

It or function is a group or statement that used together to perform a task. We can divide our code into separate subroutines.

To divide subroutine into separate subroutines is depends on the developer but we can divide it logically based on the function which performed a specific task.

In the subroutine, function and method are the same but in other languages this is different.

The subroutines are used in perl programming language because subroutine in Perl created by using sub keyword.

When we have called to function or subroutines in our program, perl compiler will stop its all executing program and goes to execute the function to execute the same and then return back to execute the remaining section code.

We have avoided this by using the return statement in our program.

Examples

Below is the example of the subroutine in Perl is as follows.

Example #1

Passing Arguments to Subroutine: Below example shows passing arguments to a subroutine.

Code:

# Defining function in perl. sub Average { # Dispay number of arguments. $number = scalar(@_); $sum_of_num = 0; foreach $item (@_) { $sum_of_num += $item; } $average_of_num = $sum_of_num / $number; print "Average of numbers : $average_of_numn"; } # Calling function average to define average of given numbers. Average(100, 200, 300, 400, 500);

Example #2

Passing List to Subroutine: Below example shows passing a list to a subroutine.

Code :

# Defining function in perl with list as arguments. sub sub_PrintList { my @sub_list = @_; print "Given list @sub_listn"; } $p = 1; @q = (2, 3, 4, 5, 6, 7, 8, 9, 10);  ## Provide list as user input. # Function call with list parameter sub_PrintList($p, @q);

Output:

Example #3

Passing Hashes to Subroutine: Below example shows passing a hashes to a subroutine. In the below example, we have to pass the hashes to the subroutine.

Code:

# Defining function in perl with hashes as arguments. sub sub_PrintHash { my (%sub_hash) = @_; foreach my $key ( keys %sub_hash ) { my $hash_value = $sub_hash{$key}; print "$key : $hash_valuen"; } } # Function call with hashes parameter sub_PrintHash(%sub_hash);

Example #4

Returning Value from a Subroutine: The below example shows returning a value from a subroutine. In the below example, we have to return value from a subroutine.

Code:

# Defining function in perl. sub Average { $number = scalar(@_); $sum_number = 0; foreach $item (@_) { $sum_number += $item; } $average_num = $sum_number / $number; return $average_num; } # Function call $num = Average(10, 20, 30, 40, 50, 60, 70, 80, 90, 100); print "Average for numbers : $numn";

Output:

Conclusion

In perl we can create our own functions it is called as subroutines, subroutines is very important to improve the code reusability. It is used to reusability of code using subroutine we can use code again and again, there is no need to write the code again.

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How Wait Method Work In Powershell? (Examples)

Definition of PowerShell Wait

PowerShell wait cmdlets are used to hold the execution for some certain period to wait for the command, job, or Process to complete, to notify a user that background job is running and ask to wait for some specific period, to restarting remote systems, and wait until it comes up, starting and stopping VMs, etc, and that depends on the command specified. If the command is for the background Job to process first then it will wait to finish and if the command is to halt the execution for a specific period then the user has to wait until the time specified.

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Syntax:

a. Wait-Process

The above command is used to wait for the processes to be stopped before accepting the new input or moving to the next commands.

b.Wait-Job

This command is used to complete the background job and execution won’t move to the next stage until the execution is finished.

c. Start -Sleep

This command halts the script execution for the specified time in seconds or milliseconds and can’t make any command or job to wait in the background but pauses the script execution.

This command suspends the execution of the script or function until the particular event is raised and continues the execution of the script after that.

e. Wait Parameters

Many commands use the -Wait parameter directly in the command to wait for that command to finish instead of using the Wait-Job command running separately.

f. Timeout

Similar to the Start-Sleep command, this command holds the execution of the script for the specified period.

How Wait Method works in PowerShell?

Once we use the Wait commands, it stops the execution until the background job or process completes and resumes the execution from the last point where it had stopped. Some commands like Start-Sleep and timeout, just pause the script but don’t run any job or process in the background.

Examples

Let us discuss examples of PowerShell Wait.

1. Wait-Process Example

When we use the command Wait-Process, it waits for the particular process or application to be stopped. This command accepts the Process ID, Name, and the Timeout in seconds.

For example, we have the SnippingTools application running and we are going to terminate it but we will wait until the process is terminated.

Get-Process SnippingTool

To use the wait command we can either use ProcessID or the Name of the process.

Write-Output ”This command will be executed after process termination”

You can also provide the timeout parameter in seconds if the process doesn’t terminate in the specified time, it will throw an error.

You can also provide the multiple process names for the Wait-Process command.

2. Start-Sleep Example

This command holds the execution for a certain amount of time and the next command waits until then. You can provide time in Seconds or milliseconds.

Write-Output "Writing First Line"

Start-Sleep -Seconds 5

Write-Output “This command will be executed after 5 seconds”

You can also provide the -milliseconds parameter.

Start-Sleep -Milliseconds 5000

c. Timeout Example

This is a cmd command but can be accessible in PowerShell as well. Once you specify the Timeout in seconds, the next commands wait until the timeout.

Write-Output “This command will be executed after 5 seconds”

Output:

Users can interrupt in the timeout specified if you want uninterrupted Timeout then use /NoBreak switch.

The only option with the /NoBreak switch is to press Ctrl+C to terminate further execution.

d. Wait-Job Example

When we use the Wait-Job command, it waits for the scriptblock to complete and executes the next line command.

Write-Output ”This line will be executed after job completes”

Output:

We can also specify the timeout for the job to complete using the -Timeout parameter in seconds in the Wait-Job cmdlet. If the job doesn’t complete during that period, the script will throw an error.

e. Wait-Event Example

This command waits for the particular event to be raised and PowerShell suspends the execution until then and resumes when the event triggers.

Wait-Event

The above command waits for any next event to trigger and suspends the PowerShell execution for that time.

We will create a new test event here to trigger the Wait-Event command.

Output:

If we have any particular source for that event, we can specify that SourceIdentifier Name.

Wait-Event -SourceIdentifier "ProcessStarted" -Timeout 200

g. -Wait Parameter in Commands

Few commands like Restart-Computer, Start-AZVM, Stop-AzVM, etc support the -Wait parameter and the next commands execute after executing the -Wait parameter command. For example,

Get-Process -ComputerName test1-win2k12

Output:

There are other commands which by default include the Wait Parameter like Start-AzVM and Stop-AzVM command.

Write-Output ”This command will be executed immediately”

To Stop VM,

Write-Output ”This command will be executed after VM Stops”

In the first command Start-AZVM, the -NoWait parameter is specified so that command won’t wait to start the VM but in the second command Stop-AZVM, the default parameter is Wait so that the next command will wait until the VM stops successfully.

Conclusion

There are many Wait cmdlets in PowerShell and supported Wait parameter in PowerShell commands so that the previous commands should complete first because sometimes the next command input depends on the output of the previous command and we need them to be executed first.

Recommended Articles

This is a guide to PowerShell Wait. Here we discuss the Definition, How Wait Method works in PowerShell and examples with code implementation. You may also have a look at the following articles to learn more –

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