Bash Quick Start Guide

Shell metacharacters

So far, all of our examples of commands and arguments have been single unquoted shell words. However, there is a set of metacharacters that have a different meaning to Bash, and trying to use them as part of a word causes problems.

For example, suppose you want to create (touch) a new file named important file. Note that there's a space in the name. If you try to create it as follows, you get unexpected results:

$ touch important file

If we list the files in the directory after running this, using ls -1 to put all the names on separate lines, we can see we've actually created two files; one named important, and one named file:

$ ls -1
file
important

This happened because the space between the two words separated them ...