Wildcards

[*] A number of characters are interpreted by the Unix shell before any other action takes place. These characters are known as wildcard characters. Usually these characters are used in place of filenames or directory names.

    *     An asterisk matches any number of characters in a filename,
               including none.
    ?     The question mark matches any single character.
    [ ]   Brackets enclose a set of characters, any one of
               which may match a single character at that position.
    -     A hyphen used within [ ] denotes a range of characters.
    ~     A tilde at the beginning of a word expands to the name
               of your home directory.  If you append another user's login
               name to the character, it refers to that user's home directory.

1. cat c* displays any file whose name begins with c including the file c, if it exists.
2. ls *.c lists all files that have a .c extension.
3. cp ../rmt?. copies every file in the parent directory that is four characters long and begins with rmt to the working directory. (The names will remain the same.)
4. ls rmt[34567] lists every file that begins with rmt and has a 3, 4, 5, 6, or 7 at the end.
5. ls rmt[3-7] does exactly the same thing as the previous example.
6. ls ~ lists your home directory.
7. ls ~hessen lists the home directory of the guy[+] with the user id hessen.