import Foundation
let pattern = #"(<\?fileVersion 4\.0\.0\?>)\s"#
let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines)
let testString = #"""
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<?fileVersion 4.0.0?>
<cproject storage_type_id="org.eclipse.cdt.core.XmlProjectDescriptionStorage">
<storageModule moduleId="org.eclipse.cdt.core.settings">
<cconfiguration id="com.st.stm32cube.ide.mcu.gnu.managedbuild.config.exe.debug.1508274248">
<storageModule buildSystemId="org.eclipse.cdt.managedbuilder.core.configurationDataProvider" id="com.st.stm32cube.ide.mcu.gnu.managedbuild.config.exe.debug.1508274248" moduleId="org.eclipse.cdt.core.settings" name="Debug">
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let substitutionString = #"$1"#
let result = regex.stringByReplacingMatches(in: testString, range: stringRange, withTemplate: substitutionString)
print(result)
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Swift 5.2, please visit: https://developer.apple.com/documentation/foundation/nsregularexpression