1.Dd July 27, 2013
 2.Dt he 1
 3.Sh NAME
 4.Nm he
 5.Nd encode/decode HTML entities just like a browser would
 6.Sh SYNOPSIS
 7.Nm
 8.Op Fl -escape Ar string
 9.br
10.Op Fl -encode Ar string
11.br
12.Op Fl -encode Fl -use-named-refs Fl -everything Fl -allow-unsafe Ar string
13.br
14.Op Fl -decode Ar string
15.br
16.Op Fl -decode Fl -attribute Ar string
17.br
18.Op Fl -decode Fl -strict Ar string
19.br
20.Op Fl v | -version
21.br
22.Op Fl h | -help
23.Sh DESCRIPTION
24.Nm
25encodes/decodes HTML entities in strings just like a browser would.
26.Sh OPTIONS
27.Bl -ohang -offset
28.It Sy "--escape"
29Take a string of text and escape it for use in text contexts in XML or HTML documents. Only the following characters are escaped: `&`, `<`, `>`, `"`, and `'`.
30.It Sy "--encode"
31Take a string of text and encode any symbols that aren't printable ASCII symbols and that can be replaced with character references. For example, it would turn `©` into `&#xA9;`, but it wouldn't turn `+` into `&#x2B;` since there is no point in doing so. Additionally, it replaces any remaining non-ASCII symbols with a hexadecimal escape sequence (e.g. `&#x1D306;`). The return value of this function is always valid HTML.
32.It Sy "--encode --use-named-refs"
33Enable the use of named character references (like `&copy;`) in the output. If compatibility with older browsers is a concern, don't use this option.
34.It Sy "--encode --everything"
35Encode every symbol in the input string, even safe printable ASCII symbols.
36.It Sy "--encode --allow-unsafe"
37Encode non-ASCII characters only. This leaves unsafe HTML/XML symbols like `&`, `<`, `>`, `"`, and `'` intact.
38.It Sy "--decode"
39Takes a string of HTML and decode any named and numerical character references in it using the algorithm described in the HTML spec.
40.It Sy "--decode --attribute"
41Parse the input as if it was an HTML attribute value rather than a string in an HTML text content.
42.It Sy "--decode --strict"
43Throw an error if an invalid character reference is encountered.
44.It Sy "-v, --version"
45Print he's version.
46.It Sy "-h, --help"
47Show the help screen.
48.El
49.Sh EXIT STATUS
50The
51.Nm he
52utility exits with one of the following values:
53.Pp
54.Bl -tag -width flag -compact
55.It Li 0
56.Nm
57successfully encoded/decoded the input and printed the result.
58.It Li 1
59.Nm
60wasn't instructed to encode/decode anything (for example, the
61.Ar --help
62flag was set); or, an error occurred.
63.El
64.Sh EXAMPLES
65.Bl -ohang -offset
66.It Sy "he --escape '<script>alert(1)</script>'"
67Print an escaped version of the given string that is safe for use in HTML text contexts, escaping only `&`, `<`, `>`, `"`, and `'`.
68.It Sy "he --decode '&copy;&#x1D306;'"
69Print the decoded version of the given HTML string.
70.It Sy "echo\ '&copy;&#x1D306;'\ |\ he --decode"
71Print the decoded version of the HTML string that gets piped in.
72.El
73.Sh BUGS
74he's bug tracker is located at <https://github.com/mathiasbynens/he/issues>.
75.Sh AUTHOR
76Mathias Bynens <https://mathiasbynens.be/>
77.Sh WWW
78<http://mths.be/he>