Métacaractère

In software, a wildcard character is a kind of placeholder represented by a single character, such as an asterisk (), which can be interpreted as a number of literal characters or an empty string. It is often used in file searches so the full name need not be typed. In telecommunications, a wildcard 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 upper-case alphanumeric characters. Whether the wildcard character represents a single character or a string of characters must be specified. In computer (software) technology, a wildcard is a symbol used to replace or represent one or more characters. Algorithms for matching wildcards have been developed in a number of recursive and non-recursive varieties. When specifying file names (or paths) in CP/M, DOS, Microsoft Windows, and Unix-like operating systems, the asterisk character (, also called "star") matches zero or more characters. For example, matches and but not . If files are named with a date stamp, wildcards can be used to match date ranges, such as *.mp4 to select video recordings from , to facilitate file operations such as copying and moving. In Unix-like and DOS operating systems, the question mark matches exactly one character. In DOS, if the question mark is placed at the end of the word, it will also match missing (zero) trailing characters; for example, the pattern will match and , but not . In Unix shells and Windows PowerShell, ranges of characters enclosed in square brackets ( and ) match a single character within the set; for example, matches any single uppercase or lowercase letter. In Unix shells, a leading exclamation mark negates the set and matches only a character not within the list. In shells that interpret as a history substitution, a leading caret can be used instead. The operation of matching of wildcard patterns to multiple file or path names is referred to as globbing.