Editing Escape character (section)

===Bourne shell===

In [[Bourne shell]] (sh), the [[asterisk]] ({{code|*}}) and [[question mark]] ({{code|?}}) characters are [[wildcard character]]s expanded via [[globbing]]. Without a preceding escape character, an {{code|*}} will expand to the names of all files in the [[working directory]] that do not start with a period [[if and only if]] there are such files, otherwise {{code|*}} remains unexpanded. So to refer to a file literally called "*", the shell must be told not to interpret it in this way, by preceding it with a backslash ({{code|\}}). This modifies the interpretation of the asterisk ({{code|*}}).

Compare:
{|
|-
| style="width:25px;"|&nbsp;<!--indented-->||
<syntaxhighlight lang="bash">
rm *    # delete all files in the current directory
</syntaxhighlight>
<syntaxhighlight lang="bash">
rm \*   # delete the file named *
</syntaxhighlight>
|}

Similarly, characters like the [[ampersand]], [[Vertical bar|pipe]] and [[semicolon]] (used for command chaining), angle brackets (used for [[Redirection (computing)|redirection]]), and parentheses have special syntactic meaning to the Bourne shell. These must also be escaped—referred to as "quoting" in the {{code|sh(1)}} manual page<ref>https://heirloom.sourceforge.net/sh/sh.1.html#8</ref>—in order to be used literally as arguments to another program:

<syntaxhighlight lang="console">
$ echo (｀-´)>     # not escaped or quoted
bash: syntax error near unexpected token `｀-´'

$ echo \(｀-´\)\>  # escaped with backslashes
(｀-´)>

$ echo '(｀-´)>'   # protected by single quotes; same effect as above
(｀-´)>

$ echo ;)          # syntax error
$ echo ';)' \;\)   # both OK
</syntaxhighlight>