Use Powershell to comment out a 'codeblock' in a text file? - regex

Question

I'm trying to comment out some code in a massive amount of files
The files all contain something along the lines of:
stage('inrichting'){
steps{
build job: 'SOMENAME', parameters: param
build job: 'SOMEOTHERNAME', parameters: param
echo 'TEXT'
}
}
The things within the steps{ } is variable, but always exists out of 0..N 'echo' and 0..N 'build job'
I need an output like:
//stage('inrichting'){
// steps{
// build job: 'SOMENAME', parameters: param
// build job: 'SOMEOTHERNAME', parameters: param
// echo 'TEXT'
// }
//}
Is there any good way to do this with PowerShell? I tried some stuff with pattern.replace but didn't get very far.
$list = Get-ChildItem -Path 'C:\Program Files (x86)\Jenkins\jobs' -Filter config.xml -Recurse -ErrorAction SilentlyContinue -Force | % { $_.fullname };
foreach ($item in $list) {
...
}

Answer 1

This is a bit tricky, as you're trying to find that whole section, and then add comment markers to all lines in it. I'd probably write an ad-hoc parser with switch -regex if your structure allows for it (counting braces may make things more robust, but is also a bit harder to get right for all cases). If the code is regular enough you can perhaps reduce it to the following:
stage('inrichting'){
steps{
... some amount of lines that don't contain braces
}
}
and we can then check for occurrence of the two fixed lines at the start and eventually two lines with closing braces:
foreach ($file in $list) {
# lines of the file
$lines = Get-Content $file
# line numbers to comment out
$linesToComment = #()
# line number of the current block to comment
$currentStart = -1
# the number of closing braces on single lines we've encountered for the current block
$closingBraces = 0
for ($l = 0; $l -le $lines.Count; $l++) {
switch -regex ($lines[$l]) {
'^\s*stage\('inrichting'\)\{' {
# found the first line we're looking for
$currentStart = $l
}
'^\s*steps\{' {
# found the second line, it may not belong to the same block, so reset if needed
if ($l -ne $currentStart + 1) { $currentStart = -1 }
}
'^\s*}' {
# only count braces if we're at the correct point
if ($currentStart -ne -1) { $closingBraces++ }
if ($closingBraces -eq 2) {
# we've reached the end, add the range to the lines to comment out
$linesToComment += $currentStart..$l
$currentStart = -1
$closingBraces = 0
}
}
}
}
$commentedLines = 0..($lines.Count-1) | % {
if ($linesToComment -contains $_) {
'//' + $lines[$_]
} else {
$lines[$_]
}
} | Set-Content $file
}
Untested, but the general idea might work.
Update: fixed and tested