@@ -1297,38 +1297,137 @@ extension NSString {
12971297 try self . init ( contentsOf: URL ( fileURLWithPath: path) , encoding: enc)
12981298 }
12991299
1300- public convenience init ( contentsOf url: URL , usedEncoding enc: UnsafeMutablePointer < UInt > ? ) throws {
1301- let readResult = try NSData ( contentsOf: url, options: [ ] )
1302-
1303- let bytePtr = readResult. bytes. bindMemory ( to: UInt8 . self, capacity: readResult. length)
1304- if readResult. length >= 2 && bytePtr [ 0 ] == 254 && bytePtr [ 1 ] == 255 {
1305- enc? . pointee = String . Encoding. utf16BigEndian. rawValue
1306- }
1307- else if readResult. length >= 2 && bytePtr [ 0 ] == 255 && bytePtr [ 1 ] == 254 {
1308- enc? . pointee = String . Encoding. utf16LittleEndian. rawValue
1300+ private static func _getEncodingFromDataByCheckingForUnicodeBOM( _ data: Data ) -> String . Encoding ? {
1301+ // Check for Byte Order Mark (BOM) at the beginning of the file
1302+ // Make sure utf32LittleEndian comes before utf16LittleEndian in the list.
1303+ let unicodeBOMs : [ ( String . Encoding , [ UInt8 ] ) ] = [
1304+ ( . utf8, [ 0xEF , 0xBB , 0xBF ] ) ,
1305+ ( . utf16BigEndian, [ 0xFE , 0xFF ] ) ,
1306+ ( . utf32LittleEndian, [ 0xFF , 0xFE , 0x00 , 0x00 ] ) ,
1307+ ( . utf16LittleEndian, [ 0xFF , 0xFE ] ) ,
1308+ ( . utf32BigEndian, [ 0x00 , 0x00 , 0xFE , 0xFF ] )
1309+ ]
1310+
1311+ for (bomEncoding, bom) in unicodeBOMs {
1312+ // Make sure that there are enough bytes in the data
1313+ if data. count >= bom. count {
1314+ var match = true
1315+ for i in 0 ..< bom. count {
1316+ if data [ i] != bom [ i] {
1317+ // The BOM doesn't match
1318+ match = false
1319+ }
1320+ }
1321+ if match {
1322+ return bomEncoding
1323+ }
1324+ }
13091325 }
1310- else {
1311- //Need to work on more conditions. This should be the default
1312- enc? . pointee = String . Encoding. utf8. rawValue
1326+ return nil
1327+ }
1328+
1329+ private static func _createCFString( fromData data: Data , withEncoding encoding: String . Encoding ) -> CFString ? {
1330+ let cf = data. withUnsafeBytes ( { ( bytes: UnsafePointer < UInt8 > ) -> CFString ? in
1331+ return CFStringCreateWithBytes ( kCFAllocatorDefault, bytes, data. count, CFStringConvertNSStringEncodingToEncoding ( encoding. rawValue) , true )
1332+ } )
1333+
1334+ return cf
1335+ }
1336+
1337+ public convenience init ( contentsOf url: URL , usedEncoding enc: UnsafeMutablePointer < UInt > ? ) throws {
1338+ // Forward to file handling init, so extended attributes can be checked
1339+ if url. isFileURL {
1340+ try self . init ( contentsOfFile: url. path, usedEncoding: enc)
1341+ return
13131342 }
1343+
1344+ let readResult = try Data ( contentsOf: url, options: [ ] )
1345+
1346+ // If the encoding can't be found, use utf8 as the default
1347+ let encoding = NSString . _getEncodingFromDataByCheckingForUnicodeBOM ( readResult) ?? . utf8
1348+ enc? . pointee = encoding. rawValue
13141349
1315- guard let enc = enc , let cf = CFStringCreateWithBytes ( kCFAllocatorDefault , bytePtr , readResult. length , CFStringConvertNSStringEncodingToEncoding ( enc . pointee ) , true ) else {
1316- throw NSError ( domain: NSCocoaErrorDomain, code: CocoaError . fileReadInapplicableStringEncoding . rawValue, userInfo: [
1350+ guard let cf = NSString . _createCFString ( fromData : readResult, withEncoding : encoding ) else {
1351+ throw NSError ( domain: NSCocoaErrorDomain, code: CocoaError . fileReadUnknownStringEncoding . rawValue, userInfo: [
13171352 " NSDebugDescription " : " Unable to create a string using the specified encoding. "
13181353 ] )
13191354 }
1355+
13201356 var str : String ?
13211357 if String . _conditionallyBridgeFromObjectiveC ( cf. _nsObject, result: & str) {
13221358 self . init ( str!)
13231359 } else {
1324- throw NSError ( domain: NSCocoaErrorDomain, code: CocoaError . fileReadInapplicableStringEncoding . rawValue, userInfo: [
1360+ throw NSError ( domain: NSCocoaErrorDomain, code: CocoaError . fileReadUnknownStringEncoding . rawValue, userInfo: [
13251361 " NSDebugDescription " : " Unable to bridge CFString to String. "
13261362 ] )
13271363 }
13281364 }
13291365
1366+ private static func _getEncodingNameFromString( _ encodingStr: String ) -> String . Encoding ? {
1367+ // Iterate through all possible CFStringEncoding values and compare to the string argument
1368+ let cfEncodings = CFStringGetListOfAvailableEncodings ( )
1369+ var encodingPtr = cfEncodings
1370+
1371+ while encodingPtr? . pointee != kCFStringEncodingInvalidId {
1372+ if let cfEncodingName = CFStringConvertEncodingToIANACharSetName ( encodingPtr!. pointee) {
1373+ var encodingName : String ?
1374+ if String . _conditionallyBridgeFromObjectiveC ( cfEncodingName. _nsObject, result: & encodingName) {
1375+ if encodingName == encodingStr {
1376+ let encoding = CFStringConvertEncodingToNSStringEncoding ( encodingPtr!. pointee)
1377+ return String . Encoding. init ( rawValue: encoding)
1378+ }
1379+ } else {
1380+ continue
1381+ }
1382+ }
1383+
1384+ encodingPtr = encodingPtr? . advanced ( by: 1 )
1385+ }
1386+
1387+ return nil
1388+ }
1389+
13301390 public convenience init ( contentsOfFile path: String , usedEncoding enc: UnsafeMutablePointer < UInt > ? ) throws {
1331- NSUnimplemented ( )
1391+ let readResult = try Data ( contentsOf: URL ( fileURLWithPath: path) , options: [ ] )
1392+ var encoding : String . Encoding ?
1393+
1394+ // Check extended attributes for 'com.apple.TextEncoding'
1395+ let attrName = " com.apple.TextEncoding "
1396+ let bufCount = getxattr ( path, attrName, nil , 0 , 0 , 0 )
1397+ if bufCount > 0 {
1398+ var buf = [ UInt8] ( repeating: 0 , count: bufCount)
1399+ if getxattr ( path, attrName, & buf, bufCount, 0 , 0 ) != - 1 {
1400+ if let attrValue = String ( bytes: buf, encoding: . utf8) {
1401+ encoding = NSString . _getEncodingNameFromString ( attrValue)
1402+ }
1403+ }
1404+ }
1405+
1406+ // If the encoding can't be found in extended attrubutes, check for a BOM
1407+ if encoding == nil {
1408+ // If the encoding can't be found, use utf8 as the default
1409+ encoding = NSString . _getEncodingFromDataByCheckingForUnicodeBOM ( readResult) ?? . utf8
1410+ }
1411+
1412+ enc? . pointee = encoding!. rawValue
1413+
1414+ guard let cf = NSString . _createCFString ( fromData: readResult, withEncoding: encoding!) else {
1415+ throw NSError ( domain: NSCocoaErrorDomain,
1416+ code: CocoaError . fileReadUnknownStringEncoding. rawValue,
1417+ userInfo: [
1418+ " NSDebugDescription " : " The file \" \( path) \" couldn't be opened because the text encoding of its contents can't be determined. " ,
1419+ " NSFilePath " : path
1420+ ] )
1421+ }
1422+
1423+ var str : String ?
1424+ if String . _conditionallyBridgeFromObjectiveC ( cf. _nsObject, result: & str) {
1425+ self . init ( str!)
1426+ } else {
1427+ throw NSError ( domain: NSCocoaErrorDomain, code: CocoaError . fileReadUnknownStringEncoding. rawValue, userInfo: [
1428+ " NSDebugDescription " : " Unable to bridge CFString to String. "
1429+ ] )
1430+ }
13321431 }
13331432}
13341433
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