I was working on my guest commentary for the upcoming Scripting Games and started thinking I would need a line numbered version of my solution to help explain. Turns out I didn't go down that road, but in the process I put together a little PowerShell to take a text file and create a line numbered version.<\/p>\n
When you are editing a file in the ISE or a script editor like PrimalScript, line numbers help you quickly jump to trouble spots with parsing errors. I decided it would be equally helpful to create a line numbered version of a script. Here's what I came up with, appropriately numbered.<\/p>\n
[cc lang=\"PowerShell\"]
\n 1 #Requires -version 2.0
\n 2
\n 3 # -----------------------------------------------------------------------------
\n 4 # Script: ConvertTo-NumberedText.ps1
\n 5 # Version: 1.0
\n 6 # Author: Jeffery Hicks
\n 7 # http:\/\/jdhitsolutions.com\/blog
\n 8 # http:\/\/twitter.com\/JeffHicks
\n 9 # Date: 3\/22\/2011
\n10 # Keywords:
\n11 # Comments:
\n12 #
\n13 # \"Those who forget to script are doomed to repeat their work.\"
\n14 #
\n15 # ****************************************************************
\n16 # * DO NOT USE IN A PRODUCTION ENVIRONMENT UNTIL YOU HAVE TESTED *
\n17 # * THOROUGHLY IN A LAB ENVIRONMENT. USE AT YOUR OWN RISK. IF *
\n18 # * YOU DO NOT UNDERSTAND WHAT THIS SCRIPT DOES OR HOW IT WORKS, *
\n19 # * DO NOT USE IT OUTSIDE OF A SECURE, TEST SETTING. *
\n20 # ****************************************************************
\n21 # -----------------------------------------------------------------------------
\n22
\n23 $File=Read-Host \"Enter the name of the file to convert to numbered output\"
\n24 $Output=Read-Host \"Enter the name of the output file\"
\n25
\n26 if (Test-Path -Path $file)
\n27 {
\n28 #read in the total contents of the file
\n29 $Content=get-content -Path $file
\n30
\n31 #get the total number of lines
\n32 $count=$content.Count
\n33
\n34 #convert the count to a string so we can find how many digits. This will
\n35 #be the padding value
\n36 $Pad=$count.ToString().Length
\n37
\n38 #initialize a counter
\n39 $i=1
\n40
\n41 #pipe the content to ForEach, building a new numbered line and pipe the results to a new
\n42 #file. The new lines are then piped to Out-File.
\n43 $content | foreach {
\n44 #use the -f operaton to construct a string with a padded line number
\n45 #and the line.
\n46 \"{0} {1}\" -f $i.ToString().PadLeft($pad),$_
\n47
\n48 #increment the counter
\n49 $i++
\n50 } | Out-File -FilePath $Output
\n51
\n52 Write-Host \"Open $Output for numbered content.\" -ForegroundColor Green
\n53 } #if
\n54 else
\n55 {
\n56 Write-Warning \"Can't find or verify $file.\"
\n57 }
\n[\/cc]<\/p>\n
I decided to keep things really simple and prompt the user in lines 23\/24 for the script to convert and the new file name.<\/p>\n
Line 26 is a quick test to verify the source file exits. If it does, then the entire contents are saved to a variable (line 29). Now the fun part.<\/p>\n
I wanted the line numbers to be justified like they are in the ISE. If my script has 134 lines then the first 9 lines needed to be indented 2 spaces and lines 10-99 indented 1. Assuming the script has more than 1 line (otherwise why are you bothering with this?), I get the total line count in line 32.<\/p>\n
To determine how much padding I'll need, I'll convert this number to a string and get its length (line 36). Armed with this value, I can now go through each line of content (line 43) and construct a new line using the -f operator (line 46). The value of the first placeholder will be the counter value (starting at 1 (line 39)), converted to a string and then padded the necessary number of spaces. The second element is the original line from the imported content.<\/p>\n
All that remains is to send the output to the new file in line 50. The main section of the script ends with a message in line 52.<\/p>\n
I doubt you'll need this often but if nothing else it offers a few lessons in the string object and the -f operator.<\/p>\n