A Peek at Metacharacters

Metacharacters are special characters that have particular meaning to your shell that dollar sign or hash mark prompt where you do your work. The two I want to look at are the asterisk and the question mark. The following is what they mean to the shell:

*	Match any number of characters.
?	Match a single character.

Extending our talk of listing files, you could list all files containing "ackle" by using this command:

 $ ls *ackle* hackle hackles tackles 

Similarly, you could find all the words that start with an "h" like this:

 $ ls h* hackle hackles 

Now, if you want to see all the seven-letter words in your directory, use this command:

 $ ls ??????? hackles tackles 

Each question mark represents a single letter position.