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Information about Wildcard Character

For other meanings of 'wild card' see wild card.


The term wildcard character has the following meanings:

Telecommunication

In telecommunications, a wildcard character is a character that may be substituted for any of a defined subset of all possible characters.
  • In high-frequency (HF) radio automatic link establishment, the wildcard character "?" may be substituted for any one of the 36 characters, "A" through "Z" and "0" through "9."
  • Whether the wildcard character represents a single character or a string of characters must be specified.

Computing

In computer (software) technology, a wildcard character can be used to substitute for any other character or characters in a string.

The asterisk (*) usually substitutes as a wildcard character for any zero or more characters, and the question mark (?) usually substitutes as a wildcard character for any one character, as in the CP/M, DOS, Microsoft Windows and POSIX (Unix) shells. (In Unix this is referred to as glob expansion.) In SQL, wildcard characters can be used in "LIKE" expressions; the percent sign (%) matches zero or more characters, and underscore (_) a single character. In many regular expression implementations, the period (.) is the wildcard character for a single character.

References

See also

External links

The term wild card was originally used in card games, but the term has evolved to describe what the Merriam-Webster Dictionary calls "an unknown or unpredictable factor" in any number of domains.
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Telecommunication is the transmission of signals over a distance for the purpose of communication. In modern times, this process typically involves the sending of electromagnetic waves by electronic transmitters, but in earlier times telecommunication may have involved the use of
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character is a unit of information that roughly corresponds to a grapheme, grapheme-like unit, or symbol, such as in an alphabet or syllabary in the written form of a natural language.

An example of a character is a letter, numeral, or punctuation mark.
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High frequency (HF) radio frequencies are between 3 and 30 MHz. Also known as the decameter band or decameter wave as the wavelengths range from one to ten decameters. Shortwave (2.310 - 25.820 MHz) overlaps and is slightly lower than HF.
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Radio is the wireless transmission of signals, by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space.
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Automatic Link Establishment, commonly known as ALE, is the worldwide de facto standard for initiating High Frequency radio communications. ALE is a feature in an HF communications transceiver system, that enables the station to make contact, or initiate a circuit, between
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string is an ordered sequence of symbols. These symbols are chosen from a predetermined set.

In programming, when stored in memory each symbol is represented using a numeric value.
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computer is a machine which manipulates data according to a list of instructions.

Computers take numerous physical forms. The first devices that resemble modern computers date to the mid-20th century (around 1940 - 1941), although the computer concept and various machines
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Computer software is a general term used to describe a collection of computer programs, procedures and documentation that perform some task on a computer system. [1]
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asterisk (*), is a typographical symbol or glyph. It is so called because it resembles a conventional image of a star (Latin astrum). Computer scientists and mathematicians often pronounce it as star (as, for example, in the A* search algorithm
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question mark (?), also known as an interrogation point, question point, query,[1] or eroteme, is a punctuation mark that replaces the full stop at the end of an interrogative sentence.
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CP/M is an operating system originally created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc. Initially confined to single tasking on 8-bit processors and no more than 64 kilobytes of memory, later versions of CP/M added multi-user variations, and
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DOS (from Disk Operating System) commonly refers to the family of closely related operating systems which dominated the IBM PC compatible market between 1981 and 1995 (or until about 2000, if Windows 9x systems are included): DR-DOS, FreeDOS, MS-DOS, Novell-DOS, OpenDOS, PC-DOS,
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Microsoft Windows

Screenshot of Windows Vista Ultimate, the latest version of Microsoft Windows.
Company/developer: Microsoft Corporation
OS family: MS-DOS/9x-based, Windows CE, Windows NT
Source model: Closed source

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POSIX (IPA: /ˈpɒsɪks/) or "Portable Operating System Interface" [1] is the collective name of a family of related standards specified by the IEEE to define the application programming interface (API) for
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Unix (officially trademarked as UNIX®) is a computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and Douglas McIlroy.
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glob() is a Unix library function that expands file names using a pattern matching notation reminiscent of regular expression syntax but without the expressive power of true regular expressions. The word "glob" is also used as a noun when discussing a particular pattern, e.g.
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SQL
Paradigm: multi-paradigm
Appeared in: 1974
Designed by: Donald D. Chamberlin and Raymond F. Boyce
Developer: IBM
Latest release: SQL:2003/ 2003
Typing discipline: static, strong
Major implementations: Many
SQL
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In mathematics, a percentage is a way of expressing a number as a fraction of 100 (per cent meaning "per hundred"). It is often denoted using the percent sign, "%". For example, 45 % (read as "forty-five percent") is equal to 45 / 100, or 0.45.
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underscore ( _ ), called LOW LINE in various computer standards, is the character with ASCII value 95. On the standard US or UK 101/102 computer keyboard it shares a key with the hyphen on the top row, to the right of the 0 key.
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In computing, a regular expression is a string that is used to describe or match a set of strings, according to certain syntax rules.

Regular expressions are used by many text editors, utilities, and programming languages to search and manipulate text based on patterns.
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Full Stop is an album released in 2000 by Annabelle Chvostek.

Track listing

  1. "Icy blue"
  2. "Messages get through"
  3. "Body Work"
  4. "Gray's Pussycat Edie"
  5. "Chills"
  6. "Blows me away"
  7. "La La La"
  8. "Booby Boo"
  9. "That in itself"

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Federal Standard 1037C, entitled Telecommunications: Glossary of Telecommunication Terms is a United States Federal Standard, issued by the General Services Administration pursuant to the Federal Property and Administrative Services Act of 1949, as amended.
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MIL-STD-188 is a series of U.S. military standards relating to telecommunications.

Purpose

Faced with “past technical deficiencies in telecommunications systems and equipment and software…that were traced to basic inadequacies in the application of
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glob() is a Unix library function that expands file names using a pattern matching notation reminiscent of regular expression syntax but without the expressive power of true regular expressions. The word "glob" is also used as a noun when discussing a particular pattern, e.g.
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A wildcard DNS record is a record in a DNS zone file that will match all requests for non-existent domain names, i.e. domain names for which there are no records at all.

Wildcards in practice

Whilst the aforegiven definition is in accordance with RFC 1034 § 4.3.
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wildmat is a pattern matching library developed by Rich Salz. Based on the wildcard syntax already used in the Bourne shell, wildmat provides a uniform mechanism for matching patterns across applications with simpler syntax than that typically offered by regular expressions.
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