What is the method called for using wildcard characters for file names in Shell Scripts?

The method used for utilizing wildcard characters in file names within shell scripts is known as file globbing. Globbing allows users to specify patterns that can match multiple file names or directories. Wildcards such as the asterisk (*) and question mark (?) are typically employed in globbing. The asterisk matches zero or more characters, whereas the question mark matches a single character.

For instance, if you use *.txt in a command, the shell interprets this pattern to match all files in the current directory that have a .txt extension, thus simplifying file management tasks. This powerful feature allows for flexibility when performing operations on groups of files without needing to explicitly list each one.

In contrast, other terms such as file expansion, file concatenation, and file indexing have separate meanings and applications that do not involve the wildcard matching process for file names. File expansion typically refers to the process of expanding parameters or variable names to their values, whereas file concatenation relates to combining the contents of multiple files into one. File indexing generally refers to creating a data structure that improves the speed of data retrieval operations on a database. Thus, file globbing is the correct terminology for the specific method of using wildcards in shell scripting.