30.10 SGML, XML, and HTML Modes

The major modes for SGML and HTML include indentation support and commands to operate on tags. This section describes the special commands of these modes. (HTML mode is a slightly customized variant of SGML mode.)

C-c C-n

Interactively specify a special character and insert the SGML ‘&’-command for that character.

C-c C-t

Interactively specify a tag and its attributes (sgml-tag). This command asks you for a tag name and for the attribute values, then inserts both the opening tag and the closing tag, leaving point between them.

With a prefix argument n, the command puts the tag around the n words already present in the buffer after point. With −1 as argument, it puts the tag around the region. (In Transient Mark mode, it does this whenever a region is active.)

C-c C-a

Interactively insert attribute values for the current tag (sgml-attributes).

C-c C-f

Skip across a balanced tag group (which extends from an opening tag through its corresponding closing tag) (sgml-skip-tag-forward). A numeric argument acts as a repeat count.

C-c C-b

Skip backward across a balanced tag group (which extends from an opening tag through its corresponding closing tag) (sgml-skip-tag-forward). A numeric argument acts as a repeat count.

C-c C-d

Delete the tag at or after point, and delete the matching tag too (sgml-delete-tag). If the tag at or after point is an opening tag, delete the closing tag too; if it is a closing tag, delete the opening tag too.

C-c ? tag <RET>

Display a description of the meaning of tag tag (sgml-tag-help). If the argument tag is empty, describe the tag at point.

C-c /

Insert a close tag for the innermost unterminated tag (sgml-close-tag). If called from within a tag or a comment, close this element instead of inserting a close tag.

C-c 8

Toggle a minor mode in which Latin-1 characters insert the corresponding SGML commands that stand for them, instead of the characters themselves (sgml-name-8bit-mode).

C-c C-v

Run a shell command (which you must specify) to validate the current buffer as SGML (sgml-validate).

C-x TAB

Toggle the visibility of existing tags in the buffer. This can be used as a cheap preview.

SGML mode and HTML mode support XML also. In XML, every opening tag must have an explicit closing tag. When sgml-xml-mode is non-nil, SGML mode (and HTML mode) always insert explicit closing tags. When you visit a file, these modes determine from the file contents whether it is XML or not, and set sgml-xml-mode accordingly, so that they do the right thing for the file in either case.