Is the asterisk is the wild-card used to represent one and only one character in find criteria?

Answer 1

The interpretation of the asterisk depends on the exact filter language and dialect in use.

For example, the Windows console supports an asterisk as a placeholder for any alphanumerical character which can be part of a file base name, that is, letters, digits, underscore, and some others, but other characters with special meaning in this context, such as a period, a colon or a backslash. For example - the instruction Dir *.txt would list every file with the extension txt.

Commonly used equivalents console applications under the Unix (Linux) family of operating systems (so-called 'shell' programs such as BASH and many others) interpret the asterisk as a placeholder for any valid file name character (that is, including the period).

In most regular expression dialects, the asterisk does not represent a particular character or group of characters at all. It is instead used to implement a multiplier, where the asterisk matches "zero or more times whichever search expression precedes the asterisk." Thus, 'AZ*' will be interpreted as "match a sequence consisting of letter A, followed by zero or more letters Z: 'A', 'AZ', 'AZZZZZ', etc.