Whole document tree

5. Running an external SGML parser

PSGML can not validate an SGML document (see below what it can and can't do). If you have a validating SGML parser, like `sgmls', you can run the parser on your file with the command C-c C-v (sgml-validate).

Some variables control this function:

User Option: sgml-validate-command

The shell command to validate an SGML document.

This is a format control string that by default should contain two %s conversion specifications: the first will be replaced by the value of sgml-declaration (or the empty string, if nil); the second will be replaced by the current buffer's file name (or the empty string, if nil).

If sgml-validate-files is non-nil, the format string should contain one %s conversion specification for each element of its result.

If sgml-validate-command is a list, then every element should be a string. The strings will be tried in order and `%'-sequences in the string will be replaced according to the list below, if the string contains `%'-sequences with no replacement value the next string will be tried.

%b

means the visited file of the current buffer

%s

means the SGML declaration specified in the sgml-declaration variable

%d

means the file containing the DOCTYPE declaration, if not in the buffer

The default value is nsgmls -s %s %s.

User Option: sgml-validate-files

If non-nil, a function of no arguments that returns a list of file names. These file names will serve as the arguments to the sgml-validate-command format control string instead of the defaults.

User Option: sgml-declaration

The name of the SGML declaration file.

User Option: sgml-offer-save

If non-nil, C-c C-v (sgml-validate) will ask about saving modified buffers before running the validate command. The default value is t.

The built-in parser can find some markup errors. The command C-c C-o (sgml-next-trouble-spot) is the best way to use the built-in parser for this. To check the whole file go to the beginning of the buffer and use C-c C-o.

Some of the markup errors not found are:

• Errors in the SGML declaration.
• Errors in attribute specifications.
• Omitted start-tags for empty elements.