Windows 7 / Getting Started

---

Formatting Output with the -f Format Operator

The -f format operator is a neat tool you can use to control how output is displayed in a script. Using the -f operator, you first identify the column format and then identify what will be in the column. The basic format is

"{0,jp} {1,jp}" -f $Item.itemx, $Item.y

The format of all of the columns is enclosed in the quotes, with each individual column enclosed in braces. The first column is 0, the second column is 1, and so on. Within the column definition, you specify whether it should be right or left justified and the number of characters the column should have. For right justification, the number is positive (such as 30); for left justification, the number is negative (such as -30).

As an example, if you want the first column to be left justified with 30 characters and the second column to be right justified with 15 characters, you'd use this to define the columns:

"{0,-30} {1,15}"

Earlier in the tutorial, you saw this code create a collection of the event logs and then loop through them using a ForEach loop, like this:

$colLog = get-EventLog -list
ForEach ($Item in $ColLog) {
Write-Output $Item.Log, $Item.MaximumKilobytes
}

However, the output wasn't pretty. You can use the -f format operator to identify how the columns should be formatted. The full script would then look like this:

$colLog = get-EventLog -list
ForEach ($Item in $ColLog) {
"{0,-30} {1,15}" -f $Item.Log, $Item.MaximumKilobytes
}

Notice that with the -f operator, you don't need to include the Write-Output clause.

Listing below shows the output on my system.

Listing: Output using the -f operator

Application 		20480
DFS Replication 	15168
HardwareEvents 		20480
Internet Explorer 	512
Key Management Service 	20480
Media Center 		8192
ODiag 			16384
OSession 		16384
Security 		512
System 			20480
Windows PowerShell 	15360

You can use the -f format operator to format as many columns as desired.