为什么这个正则表达式在 powershell 中不起作用？

Question

$pattern = 'trigger(.+?)(\r|\n|\r\n){2}'
Write-Host "PATTERN $pattern"
Write-Host ("- trigger: blah`n blah`n blah blah`n`n not blah" -replace $pattern, "trigger: none")

Output should be "- trigger: none not blah"

Answer 1

There are two problems:

• .+ matches everything except for newlines, use the inline flag (?s) or a modified dot [\S\s]+
• \r\n is the Windows line break and \n *unix; therefore it is best to make \r optional ? : (\r?\n)

$pattern = 'trigger([\s\S]+?)(\r?\n){2}'
Write-Host "PATTERN $pattern"
Write-Host ("- trigger: blah`n blah`n blah blah`n`n not blah" -replace $pattern, "trigger: none")

- trigger: none not blah