NAME
ssc - analyse static web sites at source



SYNOPSIS
ssc [...] directory
ssc -f config
ssc



DESCRIPTION
ssc (the Static Site Checker) is an opinionated HTML nit-picker, intended for people, such as its author, who hand code websites.
It doesn't just check static websites for broken links, dubious syntax, and bad semantic data, it will actively complain about
things that are perfectly legal but just a little bit untidy.

Except when serving CGI queries, it recursively scans the directory looking for HTML source files to analyse. It produces a list
of errors, warnings, comments, and other hints of imperfection. Once complete, it summarises internal site inconsistencies, and
can produce some simple statistics.

ssc ignores HTML scripts.



COMMAND LINE ONLY SWITCHES

These options are only available on the command line:

-f file                 Load configuration from file, which should be in .INI file format. See CONFIGURATION FILE FORMAT below.

-F                      Load configuration file from .ssc/config in the current directory.

-h                      Show a summary of switches and exit

-V                      Show version details and exit

--validation            Show attribute extensions and exits. Attribute extensions are additional values that can be associated with attributes
                        on many X/HTML elements.



COMMAND LINE AND CONFIGURATION FILES SWITCHES

These options are available on the command line and in configuration files:

--corpus.article        Prefer the content of <ARTICLE> when gathering corpus text.

--corpus.body           Prefer the content of <BODY> when gathering corpus text. This is the default.

--corpus.main           Prefer the content of <MAIN> when gathering corpus text.

--corpus.output file    Dump XML corpus of site into file. This is intended for use by a local search engine. If none of --corpus.article,
                        --corpus.body, or --corpus.main are specified, the content of <BODY> is used. If more than one are specified,
                        then the text collected depends on a page's content.

--general.css           Do NOT process .css files.

--general.custom el     Define a custom element 'el' for verifying the IS attribute. May be repeated.

--general.datapath dir  Look for any configuration, caches, and other useful files, in this directory.
-p dir

--general.error x       If nits of the specified category or worse are generated, then exit with an error code. Values are: 'catastrophe',
-E                      'error' (the default), 'warning', 'info', or 'comment'.

--general.ignored el    ignore attributes and content of the specified element. May be repeated.

--general.lang la       If an X/HTML file does not have a language / dialect specified (e.g. "en" for standard (British) English, "en_IE" for Irish
                        English, "lb_LU" for Luxembourgish, etc.), default to 'la'. If not given, the default is your system default, or, if none,
                        then "en_US" (the standard American dialect of English).

--general.maxfilesize n Do not process HTML source files that exceed n bytes in size. Specify 0 for unlimited, although be warned that ssc is
                        stunningly stupid in such circumstances and may even attempt to load files that exceed available memory.

--general.output        Output to the specified file. If this switch is not used, standard output is used.
-o file

--general.nochange      Report what ssc would do, but don't do it.
-n

--general.rdf           Check RDF attributes. This option currently underperforms. An extension to properly support RDF and RDFs is planned.

--general.rel           Only mention <LINK> REL values, found neither in the living standard nor at microformats.org, in debug output.

--general.slob          Ignore perfectly legal but inefficient, indeed thoroughly slobby, HTML, such as being far too lazy to get round to
                        bothering to close elements.

--general.ssi           Process Server Side Includes. Although ssc can process many server side includes, it cannot process those containing
-I                      formulae. Note that processing SSIs may cause incorrect line numbers to be mentioned when an issue is described.

--general.verbose x     Output nits to the specified verbosity: 'catastrophe', 'error', 'warning', 'info', 'comment' (the default), or '0' for
-v                      silence. Additional values are available when debugging. Each level includes its preceding level, so, for example,
                        'warning' will also output 'catastrophe' and 'error' nits.

--html.rfc1867          Ignore the RFC 1867 (INPUT=FILE) extension when processing HTML 2.0

--html.rfc1942          Ignore the RFC 1942 (tables) extension when processing HTML 2.0.

--html.rfc19802         Ignore the RFC 1980 (client side image maps) extension when processing HTML 2.0.

--html.rfc2070          Ignore the RFC 2070 (internationalisation) extension when processing HTML 2.0.

--html.tags             When an HTML file is loaded that contains no DOCTYPE, ssc normally presumes it's an HTML 1 file. This switch tells it to
                        presume the file follows an earlier HTML Tags specification (the one at CERN). This is overridden by --html.version.

--html.title n          If some <TITLE> text is longer than n characters, say so.  This applies to child text of a <TITLE> element, not the value of
-z n                    TITLE attributes.

--html.version X        If no doctype (or xml header) is specified, presume version X of HTML. X can be:
                            tags        HTML tags (1991, informal),
                            1.0         HTML 1.0 (June 1993 draft),
                            +           HTML Plus (November 1993 draft),
                            2.0         HTML 2.0 (RFC 1860),
                            3.0         HTML 3.0 (March 1995 draft),
                            3.2         HTML 3.2,
                            4.0         HTML 4.0,
                            4.1         HTML 4.01,
                            4.2         XHTML 1.0,
                            4.3         XHTML 1.1 core,
                            4.4         XHTML 2.0 (December 2010 draft),
                            5.0         W3 HTML 5.0,
                            5.1         W3 HTML 5.1,
                            5.2         W3 HTML 5.2,
                            5.3         W3 HTML 5.3 (October 2018 draft),
                            2005/1/1    WhatWG WebApps draft (January 2005),
                            ...
                            2007/1/1    WhatWG WebApps draft (January 2007),
                            2007/7/1    WhatWG HTML 5 living standard (July 2007),
                            ...
                            2021/4/1    WhatWG HTML 5 living standard (April 2021),

                            XHTML 1.0   XHTML 1.0,
                            XHTML 1.1   XHTML 1.1 core,
                            XHTML 2.0   (December 2010 draft),
                            XHTML 5.x   XHTML corresponding to equivalent W3 HTML.

                        Although you can specify exact dates for versions of the What WG HTML 5 living standard, currently only broad versions
                        published in January and July are supported (and April 2021). It is expected that, as the standard develops, more
                        precision will be applied to changes in ssc analysis.

                        Certain versions of HTML offer variants, such as loose and strict definitions. ssc picks those up from the SGML headers
                        in the HTML file, if any, and carelessly ignores them.

                        Validation of XHTML is not strict.

                        Just to remind you, there are no guarantees of accuracy (or inaccuracy).

                        Copies of the appropriate standards can be found online at source, or can be downloaded from ssc.lu.

--link.301              Normally, when ssc checks external links (--link.external) it does not report http forwarding errors
-3                      301 and 308. Use this switch to have it do so.

--link.external         Check external links, e.g. those not on the site being checked. This requires a copy of curl on the path.
-e                      Note that ssc will NOT check sites such as example.com, rather it will presume the link is valid.

--link.internal         Check internal links, e.g. those within the website being checked.
-l

--link.once             Only report each broken external link once. If, for example, the site has a number of references to http://broken.com/duff.html
-O                      which does not exist, ssc will only report the first instance of the broken link. Note that, even if it reports every occurrence
                        of the link, it will only check it the first time it encounters it (requires --link.external).

--link.revoke           Do not check whether https links' certificates have been revoked (requires --link.external).
-r

--link.xlink            Check crosslink IDs on the site being analysed. For example, if a link goes to /index.html#id, then, when this switch is set,
-X                      ssc will verify that the id exists and that it is not hidden.

--math.version          Presume this version of MathML (1, 2 or 3). The following versions are supported:
                                0   work it out from the (HTML) version of the file being analysed,
                                1   MathML 1,
                                2   MathML 2,
                                3   MathML 3,
                                4   MathML 4 (December 2020 draft).

--microdata.microdata   Check microdata found in WhatWG microdata attributes (itemprop, itemtype, etc.). Note that ssc only knows about schema.org and
-m                      n.whatwg.org microdata.

--microdata.export      Export schema.org microdata encountered. This data is exported in JSON format.

--microdata.root dir    When exporting microdata with --microdata.export, write files into the directory dir. sssc will create the
                        directory tree structure as appropriate.

--microdata.version x.y Test for schema.org microdata version X.Y
                        The following values are valid:
                                version 2: 2.0 to 2.2;
                                version 3: 3.0 to 3.9;
                                versions 4.0, 5.0, 6.0;
                                version 7: 7.0 to 7.04;
                                versions 8.0, 9.0, 10.0, 11.0, 12.0.
                        If .Y is omitted, version X.0 is presumed.

--microdata.virtual v=d When exporting microdata using --microdata.export, export the contents of virtual directory 'v' to 'd'. 'v'
                        must corresponding to a directory identified with --site.virtual. For example:
                            --microdata.virtual virtual=D:\microdata.

--microformat.verify    Verify Microformats data in class and rel attributes (see https://microformats.org/).
-M

--microformat.export    Export microformat data encountered in JSON format. This option will write files in the same directory as the source,
                        with the extension .json.

--microformat.version x Presume microformats version x. The following values are current accepted:
                                1   microformats version 1 only,
                                2   microformats version 2 only,
                                3   both microformats versions 1 and 2.

--nits.catastrophe n    redefine nit n as a catastrophe; may be repeated (the value of n can be determined using --nits.nids below).

--nits.codes            Output nit codes.

--nits.comment n        Redefine nit n as a comment; may be repeated (the value of n can be determined using --nits.nids).

--nits.debug   n        Redefine nit n as a debug message; may be repeated (the value of n can be determined using --nits.nids).

--nits.error n          Redefine nit n as an error; may be repeated (the value of n can be determined using --nits.nids).

--nits.info n           Redefine nit n as information; may be repeated (the value of n can be determined using --nits.nids).

--nits.nids             Output nit ids, which can be used to redefine nits.

--nits.silence n        Silence nit n; may be repeated (the value of n can be determined using --nits.nids).

--nits.warning n        Redefine nit n as a warning; may be repeated (the value of n can be determined using --nits.nids).

--shadow.comment        Do not delete comments when writing shadow pages.

--shadow.copy X         Create a shadow directory structure from source HTML files, with errors removed and some things tidied up. X can be:
                                no     copy nothing (default);
                                pages  write 'fixed' source files, ignore non source files;
                                hard   set up hard links to non-source files (requires source and shadow directories to be on the same disk);
                                soft   set up soft links to non-source files;
                                all    copy non HTML files too;
                                dedu   copy non HTML files too, but deduplicate them, changing links in HTML source if necessary;
                                report only report duplicates (no shadowing).
                        ssc cannot convert between versions of HTML, or between HTML and XHTML.
                        The soft and hard options are only available on systems that support file links.

--shadow.file f         Write ssc's shadow cache to file f, to accelerate future shadows of the same content.

--shadow.ignore ext     When shadowing, ignore files with this extension (may be repeated).

--shadow.info           Add a comment at or near the top of each shadowed HTML file noting its generation time.

--shadow.msg text       Insert a comment containing the text at the top of every generated page. Note that, if any SSI included file is updated, the comment
                        will appear whether or not the original page is updated.

--shadow.root dir       Where to write the shadowed site.

--shadow.ssi            Do NOT resolve SSIs when shadowing even if --general.ssi is set.

--shadow.space          Leave excess/repeated spaces and blank lines in the shadowed files untidily untouched.

--shadow.virtual v=d    When shadowing virtual directories, output the shadow of virtual directory 'v' to directory 'd'. 'v' must corresponding to a directory
                        set up using --site.virtual.

--site.domain domain    The domain name of the site is 'domain'. This can be repeated. This is used to identify any URL that is apparently external but
-S domain               is actually internal to the site.

--site.extension ext    Treat files with this extension as X/HTML source files. This may be repeated. Files with extension .html are always checked.
-x ext

--site.index file       This is the name of the index file in a directory. This can be repeated. This is used for checking internal links.
-i file

--site.root dir         This is the root of the website to analyse. ssc will recursively scan the directory analysing any HTML
-g dir                  files it finds. The default is the current directory.

--site.virtual v=a      The HTML virtual directory 'v' is located in actual directory 'a' on the local filesystem. For example:
-L v=a                      --site.virtual virtual=D:\actual

--stats.meta            Produce statistics on <META> usage in <HEAD>. Note that pragmas reported (http-equiv) are those found in the HTML source, not those
                        returned by the HTTP protocol. Note that many web servers (not all) will remove some pragmas when serving pages.

--stats.page            Produce statistics for each source file encountered.

--stats.summary         Produce a summary of overall statistics for the website.

--svg.version x         Presume any SVG code encountered is this version, unless the SVG code itself specifies a version. Versions recognised:
                            1.0,
                            1.1,
                            1.2 (really 1.2/tiny),
                            1.2/tiny,
                            1.2/full (May 2004 draft, incomplete, any conflict with tiny always resolved in favour of tiny),
                            2.0,
                            2.1 (april 2021 draft).
                        If this switch is not used, and some SVG code does not identify its version, the version is derived from the version of the host
                        X/HTML code.

--validation.minor x    When validating W3 HTML 5 source code, using this minor version of HTML 5. Valid values are 0, 1, 2, and 3.
-m x                    WhatWG versions are determined by date, corresponding roughly to the date of the (online) publication of the
                        specific version. See the --html.version switch.

--validation.microdata  Validate (schema.org) microdata.

--validation.*          Add a permitted value to a particular HTML enumeration. Can be repeated. Extendable enumerations include charset,
                        class (valid values may also be picked up from CSS files), colour, currency, http-equiv, lang, metaname, mimetype,
                        rel, and SGML. A full set of possible enumerations can be listed using the --validation switch.



CONFIGURATION FILE FORMAT

If a configuration file is used, it should be in INI file format. All content is optional.

Section and option names are derived from the long form switch name, which consists of SECTION.OPTION, laid out in the format:
[SECTION]
OPTION=yes
OPTION=123456

Switches that do not have a long form version cannot be used in a configuration file.

Note that the ssc source code includes a number of tests, all of which have configuration files. Browse them for examples.



ENVIRONMENT

QUERY_STRING            Run under OpenBSD's httpd server. See notes below.
SSC_CONFIG              If no configuration file given on the command line, use this one
SSC_ARGS                Preliminary command line parameters

If, when SSC is run, the environment variable QUERY_STRING is set to an OpenBSD httpd server CGI value that includes the parameter
html.snippet, then SSC will nitpick that snippet only. Some other parameters are processed, including general.verbose and html.version.



EXIT STATUS
If no errors are found, ssc exits with 0, otherwise it exits with a value > 0.



EXAMPLES

To verify the version of ssc:
ssc -V

To check the static web side source directory /home/site/wwwroot:
ssc /home/site/wwwroot

To check a static website for example.com,  in the current directory, that uses server side includes,
including verification of external links, with very verbose output:
ssc -e -I -x html -x shtml -s example.com -v 5 -i index.shtml

To check a static web side in the current directory, with a virtual directory, verifying microformats:
ssc -L vitual=/home/site/virtual -M

To check a static web site using a configuration file:
ssc -f config.file

A simple configuration file might contain:
[general]
verbose=4
output=simple.out
[site]
domain=example.edu
extension=html
index=index.html
root=simple

A configuration file to check a site against HTML 5.2 and SVG 1.1 might contain:
[general]
output=site.out
class=yes
[link]
check=yes
[site]
domain=example.edu
extension=html
index=index.html
root=site
[html]
version=5.2
[svg]
version=1.1

A configuration file to check against a particular WhatWG living standard, gathering statistics:
[general]
output=jan21.out
[html]
version=2021/01/01
[link]
check=yes
[microdata]
version=11.0
[site]
domain=example.edu
extension=html
index=index.html
root=site
[stats]
summary=yes
meta=yes

A configuration file to shadow copy and deduplicate a site might contain:
[general]
output=dedu.out
class=yes
[site]
domain=example.edu
extension=html
index=index.html
root=site
[shadow]
copy=5
root=shadow
file=dedu.ndx

A configuration file to export microdata preparing against schema.org version 7.2 might contain:
[general]
output=export.out
class=yes
[site]
domain=example.edu
extension=html
index=index.html
root=site
[link]
check=yes
[microdata]
export=yes
root=export
version=7.2



PREPARING and UPDATING a SITE

These files are based on the steps I take to update an OpenBSD website.

Presumine a directory containing the following:
site.conf    ssc configuration file for a website
site         shadow output produced by ssc

Then I run a script like this:

ssc -f site.conf
upload.sh site /var/www/site-upload server user 0
ssh user@server "cd /var/www ; mv site x ; mv site-upload site ; mv x site-upload ; ln -sf site htdocs"

upload.sh is a macos bash script that can be found among the source code. Note that I have
rather naughtily replaced OpenBSD's httpd document directory /var/www/htdocs with a link.

Here is site.conf:

[general]
verbose=info
class=yes
output=site.out
ssi=yes
ignore=pre
rpt=yes

[html]
version=2021/04/01

[link]
check=yes
xlink=yes

[microformat]
verify=yes

[site]
domain=example.com
extension=html
extension=shtml
index=index.shtml
root=corrupt_source

[stats]
summary=yes

[shadow]
copy=dedu
root=site
file=site.ndx
ignore=inc
info=yes




SEE ALSO
tidy



STANDARDS
A full set of standards used to guide the development of ssc can be viewed at https://ssc.lu/. These are copied from
many sources online, including https://w3.org/ and https://whatwg.org/. Check https://ssc.lu/ for details.



HISTORY
ssc is written by Dylan Harris, https://ssc.lu/.
