Ldap filter beautifier

example.go

package main

import (
  "fmt"
  "./ldap"
)

var filter = "(&(&(&(& (mailnickname=*) (| (&(objectCategory=person)(objectClass=user)(|(homeMDB=*)(msExchHomeServerName=*))) )))(objectCategory=user)(department=IT)(physicalDeliveryOfficeName=Amsterdam)))"

func main() {
  fmt.Printf(ldap.FormatFilter(filter))
}

ldap.go

package ldap

import (
	"strings"
)

// inspired by https://blogs.technet.microsoft.com/389thoughts/2016/11/24/ldap-query-prettyfier/
func FormatFilter(filter string) string {
	buffer := new(strings.Builder)

	noSpaces := strings.Replace(filter, " ", "", -1)
	noSpaces = strings.Replace(noSpaces, "\n", "", -1)

	tabLevel := 0
	tabString := "  "
	inline := false
	for _, char := range noSpaces {
		switch char {
		case '(':
			buffer.WriteString("\n")
			buffer.WriteString(strings.Repeat(tabString, tabLevel))
			buffer.WriteString("(")
			tabLevel = tabLevel + 1
			inline = false
		case ')':
			tabLevel = tabLevel - 1
			if !inline {
				buffer.WriteString(strings.Repeat(tabString, tabLevel))
			}
			buffer.WriteString(")\n")
			inline = false
		default:
			inline = true
			buffer.WriteRune(char)
		}
	}

	return buffer.String()
}

I was looking for PowerShell in the first place, but the original inspiration cited has disappeared from MS site. So here is a re-re-write in PowerShell:

# inspired by https://blogs.technet.microsoft.com/389thoughts/2016/11/24/ldap-query-prettyfier/
function Format-LDAPFilter($ldapFilterString) {
	$tabLevel = 0
	$indentationString = "  " #you can do a single tab, two spaces, four spaces, etc.
	$inline = $false
	$ldapFilterStringRewritten = ""
	#Eliminate whitespaces first.
	$ldapFilterString = $ldapFilterString -replace "\s+",""

	for ($i = 0; $i -lt $ldapFilterString.length; $i++) {
		switch ($ldapFilterString[$i]) {
			'('{
				$ldapFilterStringRewritten += "`n"
				$ldapFilterStringRewritten += $indentationString * $tabLevel
				$ldapFilterStringRewritten += "("
				$tabLevel += 1
				$inline = $false
			}
			')'{
				$tabLevel -= 1
				if (-NOT $inline) {
					$ldapFilterStringRewritten += $indentationString * $tabLevel
				}
				$ldapFilterStringRewritten += ")" #`n
				if (($ldapFilterString.length - $i) -gt 1 -AND $ldapFilterString[$i+1] -ne '(') {
					$ldapFilterStringRewritten += "`n"
				}                
				$inline = $false
			}
			default{
				$inline = $true
				$ldapFilterStringRewritten += $ldapFilterString[$i]
			}
		}
	}

	$ldapFilterStringRewritten  #implicit return
}