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The most common thing you will use the if statement for is comparing two items with each other.
#POWERSHELL COMPARE FOLDERS ONE AT A TIME FULL#
You need to provide a full scriptblock with braces for it to work correctly.
#POWERSHELL COMPARE FOLDERS ONE AT A TIME CODE#
In some languages, you can place a single line of code after the if statement and it will get executed. It was $true and would have executed the Write-Output command inside the scriptblock. In the previous example, the if statement was just evaluating the $condition variable. If the value was $false, then it would skip over that scriptblock. If it evaluates to $true, then it will executes the scriptblock in the braces. The first thing the if statement does is evaluate the expression in parentheses. Here is a very basic example of the if statement: This is exactly what the if statement does. You have one statement or value to evaluate, then execute a different sections of code based on that evaluation. This is what I mean by conditional execution. Your scripts will often need to make decisions and perform different logic based on those decisions. -gt -ge -lt -le for greater than or less than.Today we will take a deep dive into one of the most fundamental commands in PowerShell. One of those statements is the if statement. Either use c:\folders\folder1\ for all paths or c:\folders\folder1.Like many other languages, PowerShell has statements for conditionally executing code in your scripts. Also, be consistent with how you write the paths(if you include the \ or not). Remember that the PrimaryPath has to be a masterlocation(contents are correct). Use parallel hash table 2 to look up hash codes found with a count less 4, to find out what the file path(s) and server(s) were. Look for hash codes in hash table 1 with a count of less than 4. while you pass throug the result files) that keys on each hash code to an array of paths/servers for that hash code.Ĥ. You can have a parallel hash table (built at that same time as 2. Process the files into a hash table that keys on the hashcodes and counts each hash code.ģ. Write the hashes, file paths, severnames to files on each server as you are processing folders for hashes, and bring those files back when done.Ģ. This can easily be remedied by having PS fire some faster hash generating command, such as this one, md5sums.ġ. accesible to the servers involved-the database table. You end up with something easily manipulated and "distributed",i.e.You could easily do this for 100 folders. Your Powershell code to generate the hashes is one identical function that gets run on each server.The hashes serve as your point of comparison. You don't have to run a four-way Compare-Object.Why this way of doing things may be helpful above).Īll of this can be done from within PS, of course. find any file path (you may have to process the path string to get it to the same relative root for each server ) where there are differing hashes (although this might be covered by 1.find any hash where there are fewer than 4 instances of the hash.Then, if you've used a database table, write a few simple queries: Store the hash and the full path and server name somewhere, preferrably a database table accessible from all four servers-it'll make processing much easier. Traverse each server's desired folder-tree (you want to do this on the servers involved for performance reasons, not over a network share!) and generate a hash on each file you find. BTW, PSCX has the Get-Hash commandlet which will help you do this. I'd go about it with a hash based approach, and possibly use a database table somehwere to help yourself out.