-
-
Save achansonjr/8d0f3066bb2c4aabf1f96711d4d64015 to your computer and use it in GitHub Desktop.
Swift: Generate hex dumps for arrays/sequences of bytes.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| // hexdump.swift | |
| // | |
| // This file contains library functions for generating hex dumps. | |
| // | |
| // The functions intended for client use are | |
| // | |
| // - `printHexDumpForBytes(_:)` | |
| // - `printHexDumpForStandardInput()` | |
| // - `hexDumpStringForBytes(_:)` | |
| // - `logHexDumpForBytes(_:)` | |
| // | |
| // The `forEachHexDumpLineForBytes(_:, processLine:)` function is available | |
| // to implement hex dumps to other types of input sources and output | |
| // destinations, and other lower-level functions are available to construct | |
| // different formats of hex-dump output. | |
| import Cocoa | |
| /// Split a sequence into equal-size chunks and process each chunk. | |
| /// | |
| /// Each chunk will have the specified number of elements, except for the last chunk, | |
| /// which will be as long as necessary for the remainder of the data. | |
| /// | |
| /// - parameters: | |
| /// - sequence: Sequence of data elements. | |
| /// - perChunkCount: Number of elements in each chunk. | |
| /// - processChunk: Function that takes an offset into the data and array of data elements. | |
| public func forEachChunkOfSequence<S : Sequence>(sequence: S, perChunkCount: Int, processChunk: (Int, [S.Iterator.Element]) -> ()) | |
| { | |
| var offset = 0 | |
| var chunk = Array<S.Iterator.Element>() | |
| for element in sequence { | |
| chunk.append(element) | |
| if chunk.count == perChunkCount { | |
| processChunk(offset, chunk) | |
| chunk.removeAll() | |
| offset += perChunkCount | |
| } | |
| } | |
| if chunk.count > 0 { | |
| processChunk(offset, chunk) | |
| } | |
| } | |
| /// Get hex representation of a byte. | |
| /// | |
| /// - parameter byte: A `UInt8` value. | |
| /// | |
| /// - returns: A two-character `String` of hex digits, with leading zero if necessary. | |
| public func hexStringForByte(byte: UInt8) -> String { | |
| return String(format: "%02x", UInt(byte)) | |
| } | |
| /// Get hex representation of an array of bytes. | |
| /// | |
| /// - parameter bytes: A sequence of `UInt8` values. | |
| /// | |
| /// - returns: A `String` of hex codes separated by spaces. | |
| public func hexStringForBytes<S: Sequence>(bytes: S) -> String where S.Iterator.Element == UInt8 | |
| { | |
| return bytes.lazy.map(hexStringForByte).joined(separator: " ") | |
| } | |
| /// Get printable representation of character. | |
| /// | |
| /// - parameter byte: A `UInt8` value. | |
| /// | |
| /// - returns: A one-character `String` containing the printable representation, or "." if it is not printable. | |
| public func printableCharacterForByte(byte: UInt8) -> String { | |
| return (isprint(Int32(byte)) != 0) ? String(UnicodeScalar(byte)) : "." | |
| } | |
| /// Get printable representation of an array of characters. | |
| /// | |
| /// - parameter bytes: A sequence of `UInt8` values. | |
| /// | |
| /// - returns: A `String` of characters containing the printable representations of the input bytes. | |
| public func printableTextForBytes<S: Sequence>( | |
| bytes: S | |
| ) -> String where S.Iterator.Element == UInt8 | |
| { | |
| return bytes.lazy.map(printableCharacterForByte).joined(separator: "") | |
| } | |
| /// Count of bytes printed per row in a hex dump. | |
| public let HexBytesPerRow = 16 | |
| /// Generate hex-dump output line for a row of data. | |
| /// | |
| /// Each line is a string consisting of an offset, hex representation | |
| /// of the bytes, and printable ASCII representation. There is no | |
| /// end-of-line character included. | |
| /// | |
| /// - parameters: | |
| /// - offset: Numeric offset into the input data sequence. | |
| /// - bytes: Sequence of `UInt8` values to be hex-dumped for this line. | |
| /// | |
| /// - returns: A `String` with the format described above. | |
| public func hexDumpLineForOffset<S: Sequence>( | |
| offset: Int, | |
| bytes: S | |
| ) -> String where S.Iterator.Element == UInt8 | |
| { | |
| let hex = hexStringForBytes(bytes: bytes) | |
| let paddedHex = String(format: "%-47s", NSString(string: hex).utf8String!) | |
| let printable = printableTextForBytes(bytes: bytes) | |
| return String(format: "%08x %@ %@", offset, paddedHex, printable) | |
| } | |
| /// Given a sequence of bytes, generate a series of hex-dump lines. | |
| /// | |
| /// - parameters: | |
| /// - bytes: Sequence of `UInt8` values to be hex-dumped. | |
| /// - processLine: Function to be invoked for each generated line. | |
| public func forEachHexDumpLineForBytes<S: Sequence>( bytes: S, processLine: @escaping (String) -> ()) where S.Iterator.Element == UInt8 | |
| { | |
| forEachChunkOfSequence(sequence: bytes, perChunkCount: HexBytesPerRow) { offset, chunk in | |
| let line = hexDumpLineForOffset(offset: offset, bytes: chunk) | |
| processLine(line) | |
| } | |
| } | |
| /// Dump a sequence of bytes as hex to standard output. | |
| /// | |
| /// - parameter bytes: Sequence of `UInt8` values to be hex-dumped. | |
| public func printHexDumpForBytes<S: Sequence>(bytes: S) where S.Iterator.Element == UInt8 | |
| { | |
| forEachHexDumpLineForBytes(bytes: bytes) { print($0) } | |
| } | |
| /// Print hex dump for standard input to standard output. | |
| public func printHexDumpForStandardInput() { | |
| let standardInputAsUInt8Sequence = AnyIterator { () -> UInt8? in | |
| let ch = getchar() | |
| return (ch == EOF) ? nil : UInt8(ch) | |
| } | |
| printHexDumpForBytes(bytes: standardInputAsUInt8Sequence) | |
| } | |
| /// Dump a sequence of bytes to a `String`. | |
| /// | |
| /// - parameter bytes: Sequence of `UInt8` values to be hex-dumped. | |
| /// | |
| /// - returns: A `String`, which may contain newlines. | |
| public func hexDumpStringForBytes<S: Sequence>(bytes: S) -> String where S.Iterator.Element == UInt8 | |
| { | |
| var s = "" | |
| forEachHexDumpLineForBytes(bytes: bytes) { s += $0 + "\n" } | |
| return s | |
| } | |
| /// Dump a sequence of bytes to the log. | |
| /// | |
| /// - parameter bytes: Sequence of `UInt8` values to be hex-dumped. | |
| public func logHexDumpForBytes<S: Sequence>(bytes: S) where S.Iterator.Element == UInt8 | |
| { | |
| forEachHexDumpLineForBytes(bytes: bytes) { NSLog("%@", $0) } | |
| } | |
| // MARK:- Tests | |
| let testString = "This is test data for my hex-dump code.\nIt has two lines.\n" | |
| let testData = [UInt8](testString.utf8) | |
| print("Test printHexDumpForBytes:") | |
| printHexDumpForBytes(testData) | |
| print("Test hexDumpStringForBytes:") | |
| print(hexDumpStringForBytes(testData)) | |
| // Test printHexDumpForBytes: | |
| // 00000000 54 68 69 73 20 69 73 20 74 65 73 74 20 64 61 74 This is test dat | |
| // 00000010 61 20 66 6f 72 20 6d 79 20 68 65 78 2d 64 75 6d a for my hex-dum | |
| // 00000020 70 20 63 6f 64 65 2e 0a 49 74 20 68 61 73 20 74 p code..It has t | |
| // 00000030 77 6f 20 6c 69 6e 65 73 2e 0a wo lines.. | |
| // Test hexDumpStringForBytes: | |
| // 00000000 54 68 69 73 20 69 73 20 74 65 73 74 20 64 61 74 This is test dat | |
| // 00000010 61 20 66 6f 72 20 6d 79 20 68 65 78 2d 64 75 6d a for my hex-dum | |
| // 00000020 70 20 63 6f 64 65 2e 0a 49 74 20 68 61 73 20 74 p code..It has t | |
| // 00000030 77 6f 20 6c 69 6e 65 73 2e 0a wo lines.. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment