import Foundation
let pattern = #"<img\b[^>]*src\s*=\s*"cid[^"]*"[^>]*>"#
let regex = try! NSRegularExpression(pattern: pattern, options: [.anchorsMatchLines, .caseInsensitive])
let testString = #"In other words <img src = "http://example.com/images/someimage.jpg"> needs to stay. But, <img src = "cid:ii_id8bx9qh0_14f205b0a5e7738a"> needs to go. "#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let substitutionString = #""#
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