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ASCII, an acronym for American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. ASCII has just 128 code points, of which only 95 are printable characters, which severely limit its scope. The set of available punctuation had significant impact on the syntax of computer languages and text markup. ASCII hugely influenced the design of character sets used by modern computers, including Unicode which has over a million code points, but the first 128 of these are the same as ASCII.
In computer programming, a string is traditionally a sequence of characters, either as a literal constant or as some kind of variable. The latter may allow its elements to be mutated and the length changed, or it may be fixed. A string is generally considered as a data type and is often implemented as an array data structure of bytes that stores a sequence of elements, typically characters, using some character encoding. String may also denote more general arrays or other sequence data types and structures.
UTF-8 is a character encoding standard used for electronic communication. Defined by the Unicode Standard, the name is derived from Unicode Transformation Format – 8-bit. Almost every webpage is stored in UTF-8.
UTF-16 (16-bit Unicode Transformation Format) is a character encoding method capable of encoding all 1,112,064 valid code points of Unicode. The encoding is variable-length as code points are encoded with one or two 16-bitcode units. UTF-16 arose from an earlier obsolete fixed-width 16-bit encoding now known as UCS-2 (for 2-byte Universal Character Set), once it became clear that more than 216 (65,536) code points were needed, including most emoji and important CJK characters such as for personal and place names.
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A hex editor is a computer program that allows for manipulation of the fundamental binary data that constitutes a computer file. The name 'hex' comes from 'hexadecimal', a standard numerical format for representing binary data. A typical computer file occupies multiple areas on the storage medium, whose contents are combined to form the file. Hex editors that are designed to parse and edit sector data from the physical segments of floppy or hard disks are sometimes called sector editors or disk editors.
This article compares Unicode encodings in two types of environments: 8-bit clean environments, and environments that forbid the use of byte values with the high bit set. Originally, such prohibitions allowed for links that used only seven data bits, but they remain in some standards and so some standard-conforming software must generate messages that comply with the restrictions. The Standard Compression Scheme for Unicode and the Binary Ordered Compression for Unicode are excluded from the comparison tables because it is difficult to simply quantify their size.
Windows code pages are sets of characters or code pages used in Microsoft Windows from the 1980s and 1990s. Windows code pages were gradually superseded when Unicode was implemented in Windows, although they are still supported both within Windows and other platforms, and still apply when Alt code shortcuts are used.
In computer data, a substitute character (␚) is a control character that is used to pad transmitted data in order to send it in blocks of fixed size, or to stand in place of a character that is recognized to be invalid, erroneous or unrepresentable on a given device. It is also used as an escape sequence in some programming languages.
The following is a comparison of notable hex editors.
Motorola S-record is a file format, created by Motorola in the mid-1970s, that conveys binary information as hex values in ASCII text form. This file format may also be known as SRECORD, SREC, S19, S28, S37. It is commonly used for programming flash memory in microcontrollers, EPROMs, EEPROMs, and other types of programmable logic devices. In a typical application, a compiler or assembler converts a program's source code to machine code and outputs it into a HEX file. The HEX file is then imported by a programmer to write the machine code into non-volatile memory, or is transferred to the target system for loading and execution.
GNU Unifont is a free Unicode bitmap font created by Roman Czyborra. The main Unifont covers all of the Basic Multilingual Plane (BMP). The "upper" companion covers significant parts of the Supplementary Multilingual Plane (SMP). The "Unifont JP" companion contains Japanese kanji present in the JIS X 0213 character set.
Extended ASCII is a repertoire of character encodings that include the original 96 ASCII character set, plus up to 128 additional characters. There is no formal definition of "extended ASCII", and even use of the term is sometimes criticized, because it can be mistakenly interpreted to mean that the American National Standards Institute (ANSI) had updated its ANSI X3.4-1986 standard to include more characters, or that the term identifies a single unambiguous encoding, neither of which is the case.
FlexHex is a freeware hex editor for Microsoft Windows that can edit files, NTFS alternate streams and sparse data, OLE compound files, logical disks, and physical drives.
References
- ↑ "5 Best hex editors as of 2020". Slant.
- ↑ Marak, Victor (2015). Windows Malware Analysis Essentials. Packt Publishing Ltd. ISBN 9781785281518.
- ↑ "6 Hex Editors for Malware Analysis". SANS Digital Forensics and Incident Response Blog. Archived from the original on 2020-01-15. Retrieved 2020-01-17.
- ↑ Nolan, Godfrey (2014). Bulletproof Android: Practical Advice for Building Secure Apps. Addison-Wesley Professional. ISBN 9780133993325.
- ↑ Mandia, Kevin; Pepe, Matthew; Luttgens, Jason (2014). Incident Response & Computer Forensics, Third Edition. McGraw Hill Professional. ISBN 9780071798686.
- ↑ McClure, Stuart; Scambray, Joel; Kurtz, George (2012). Hacking Exposed 7: Network Security Secrets and Solutions. McGraw Hill Professional. ISBN 9780071780285.
- ↑ "Hex Editors". Malware-Analyzer. Archived from the original on 2020-08-19. Retrieved 2020-01-17.
- ↑ "x86 Disassembly/Analysis Tools". wikibooks.org.
- ↑ "Malware Forensic Field Guides: Tool Box". Syngress.
- ↑ Sikorski, Michael; Honig, Andrew (2012). Practical Malware Analysis: A Hands-On Guide to Dissecting Malicious Software. No Starch Press. ISBN 9781593272906.