Wildcard character.html



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 command line interpreters of CP/M, DOS, Microsoft Windows and Unix-like operating systems. 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 Microsoft Access, wildcard characters can be used in "LIKE" expressions; the asterisk sign (*) matches zero or more characters, and question mark (?) a single character. In many regular expression implementations, the period (.) is the wildcard character for a single character.

References

• Federal Standard 1037C and from MIL-STD-188

See also

• glob (programming)
• Wildcard DNS record
• wildmat

External links

• How to Use Wildcards
• shwild: Shell-compatible wildcards (C/C++)