NAME¶
hxindex - insert an index into an HTML document
SYNOPSIS¶
hxindex [
-t ] [
-x ] [
-n ] [
-f ] [
-r ] [
-c classes ] [
-b base ] [
-i
indexdb ] [--] [
file-or-URL ]
DESCRIPTION¶
The
hxindex looks for terms to be indexed in a document, collects them,
turns them into target anchors and creates a sorted index as an HTML list,
which is inserted at the place of a placeholder in the document. The resulting
document is written to standard output.
The index is inserted at the place of a comment of the form
<!--index-->
or between two comments of the form
<!--begin-index-->
...
<!--end-index-->
In the latter case, all existing content between the two comments is removed
first.
Index terms are either elements of type
<dfn> or elements with a
class attribute of
"index". (For backward compatibility, also
class attributes
"index-inst" and
"index-def" are recognized.)
<dfn> elements (and
class
"index-def") are considered more important than
elements with class
"index" and will appear in bold in the
generated index.
The option
-c adds additional classes, that are aliases for
"index".
By default, the contents of the element are taken as the index term. Here are
two examples of occurrences of the index term "shoe":
A <dfn>shoe</dfn> is a piece of clothing that...
completed by a leather <span class="index">shoe</span>...
If the term to be indexed is not equal to the contents of the element, the
title attribute can be used to give the correct term:
... <dfn title="shoe">Shoes</dfn> are pieces of clothing that...
... with two leather <span class="index" title="shoe">shoes</span>...
The
title attribute must also be used when the index term is a subterm of
another. Subterms appear indented in the index, under their head term. To
define a subterm, use a
title attribute with two exclamation marks
("!!") between the term and the subterm, like this:
<dfn title="shoe!!leather">...</dfn>
<dfn title="shoe!!invention of">...</dfn>
<em class="index" title="shoe!!protective!!steel nosed">...</em>
As the last example above shows, there can be multiple levels of sub-subterms.
The
title attribute also allows multiple index terms to be associated
with a single occurrence. The multiple terms are separated with a vertical bar
("|"). Compare the following examples with the ones above:
<dfn title="shoe|boot">...</dfn>
<dfn title="shoe!!invention of|inventions!!shoe">...</dfn>
These two elements both insert two terms into the index. Note that the second
example above combines subterms and multiple terms.
It is possible to run index on a file that already has an index. The old target
anchors and the old index will be removed before being re-generated.
OPTIONS¶
The following options are supported:
- -t
- By default, hxindex adds an ID attribute to the
element that contains the occurrence of a term and also inserts an
<a> element inside it with a name attribute equal to
the ID. This is to allow old browsers that ignore ID attributes, such as
Netscape 4, to find the target as well. The -t option suppresses
the <a> element.
- -x
- This option turns on XML syntax conventions: empty elements
will end in /> instead of > as in HTML. -x
implies -t.
- -i indexdb
- hxindex can read an initial index from a file and
write the merged collection of index terms back to that file. This allows
an index to span several documents. The -i option is used to give
the name of the file that contains the index.
- -b base
- This option is useful in combination with -i to give
the base URL reference of the document. By default, hxindex will
store links to occurrences in the indexdb file in the form
#anchor, but when -b is given, the links will look like
base#anchor instead.
- -c class[,class[,...]]
- Normal index terms are recognized because they have a class
of "index". The -c option adds additional,
comma-separated class names that will be considered aliases for
"index". E.g., -c instance will make sure that
<span class="instance">term</span> is
recognized as a term for the index.
- -n
- By default, the index consists of links with "#"
as the anchor text. Option -n causes the link text to consist of
the section numbers of the sections in which the terms occur, falling back
to "#" only if no section number could be found. Section numbers
are found by looking for the nearest preceding start tag with a class of
"secno" or "no-num". In the case of "secno",
the contents of that element are taken as the section number. In the case
of "no-num" the section is assumed to have no number and
hxindex will print a "#" instead. These classes are also
used by hxnum(1), so it is useful to run hxindex
after hxnum, e.g.,
hxnum myfile.html | hxindex -n >mynewfile.html
- -f
- Remove title attributes that were used for the index
as well as the comments that delimit the inserted index. This avoids that
browsers display these attributes. Note that hxindex cannot be run
again on its own output if this option is used. (Mnemonic: "
freeze" or " final".)
- -r
- Do not ignore trailing punctuation when sorting index
terms. E.g., if two terms are written as
<dfn>foo,</dfn>... <span class=index>foo</span>
hxindex will normally ignore the comma and treat them as the same
term, but with -r, they are treated as different. This affects
trailing commas (,), semicolons (;), colons (:), exclamations mark (!),
question marks (?) and full stops (.). A final full stop is never ignored
if there are two or more in the term, to protect abbreviations
("B.C.") and ellipsis ("more..."). This does
not affect how the index term is printed (it is always printed as
it appears in the text), only how it is compared to similar terms.
(Mnemonic: " raw".)
OPERANDS¶
The following operand is supported:
- file-or-URL
- The name of an HTML or XML file or the URL of one. If
absent, or if the file is "-", standard input is read
instead.
EXIT STATUS¶
The following exit values are returned:
- 0
- Successful completion.
- >0
- An error occurred in parsing the HTML file.
ENVIRONMENT¶
The input is assumed to be in UTF-8, but the current locale is used to determine
the sorting order of the index terms. I.e.,
hxindex looks at the LANG,
LC_ALL and/or LC_COLLATE environment variables. See
locale(1).
To use a proxy to retrieve remote files, set the environment variables
http_proxy or
ftp_proxy. E.g.,
http_proxy="http://localhost:8080/"
BUGS¶
Assumes UTF-8 as input. Doesn't expand character entities (apart from the
standard ones: "&", "<",
">" and """). Instead, pipe the input
through
hxunent(1) and, if needed,
asc2xml(1) to convert it to
UTF-8.
Remote files (specified with a URL) are currently only supported for HTTP.
Password-protected files or files that depend on HTTP "cookies" are
not handled. (You can use tools such as
curl(1) or
wget(1) to
retrieve such files.)
SEE ALSO¶
asc2xml(1),
hxnormalize(1),
hxnum(1),
hxprune(1),
hxtoc(1),
hxunent(1),
xml2asc(1),
locale(1),
UTF-8 (RFC 2279)