Learning Unix for Mac OS X, Second Edition

File and Directory Wildcards

When you have a number of files named in series (for example, chap1 to chap12) or filenames with common characters (such as aegis, aeon, and aerie), you can use wildcards to specify many files at once. These special characters are * (asterisk), ? (question mark), and [ ] (square brackets). When used in a file or directory name given as an argument on a command line, the following is true:

*

An asterisk stands for any number of characters in a filename. For example, ae* would match aegis, aerie, aeon, etc. if those files were in the same directory. You can use this to save typing for a single filename (for example, al* for alphabet.txt) or to choose many files at once (as in ae*). A * by itself matches all file and subdirectory names in a directory, with the exception of any starting with a period. To match all your dot files, try .??*.

?

A question mark stands for any single character (so h?p matches hop and hip, but not help).

[]

Square brackets can surround a choice of single characters (i.e., one digit or one letter) you’d like to match. For example, [Cc]hapter would match either Chapter or chapter, but chap[12] would match chap1 or chap2. Use a hyphen (-) to separate a range of consecutive characters. For example, chap[1-3] would match chap1, chap2, or chap3.

The following examples show the use of wildcards. The first command lists all the entries in a directory, and the rest use wildcards to list just some of the entries. The last one ...