Variable: magic-fallback-mode-alist
magic-fallback-mode-alist is a variable defined in files.el.gz.
Value
((image-type-auto-detected-p . image-mode)
("\\(PK00\\)?[P]K" . archive-mode)
("\\(?:<\\?xml[
\n]+[^>]*>\\)?[
\n]*<\\(?:!--\\(?:[^-]\\|-[^-]\\)*-->[
\n]*<\\)*\\(?:!DOCTYPE[
\n]+[^>]*>[
\n]*<[
\n]*\\(?:!--\\(?:[^-]\\|-[^-]\\)*-->[
\n]*<\\)*\\)?[Hh][Tt][Mm][Ll]"
. mhtml-mode)
("<![Dd][Oo][Cc][Tt][Yy][Pp][Ee][
\n]+[Hh][Tt][Mm][Ll]"
. mhtml-mode)
("<\\?xml " . xml-mode)
("[
\n]*<\\(?:!--\\(?:[^-]\\|-[^-]\\)*-->[
\n]*<\\)*!DOCTYPE "
. sgml-mode)
("\320\317\340\241\261\341" . doc-view-mode-maybe)
("%!PS" . ps-mode) ("# xmcd " . conf-unix-mode))
Documentation
Like magic-mode-alist but has lower priority than auto-mode-alist.
Each element looks like (REGEXP . FUNCTION) or (MATCH-FUNCTION . FUNCTION).
After visiting a file, if REGEXP matches the text at the beginning of the
buffer (case-sensitively), or calling MATCH-FUNCTION returns non-nil,
normal-mode will call FUNCTION, provided that magic-mode-alist and
auto-mode-alist have not specified a mode for this file.
If FUNCTION is nil, then it is not called.
Probably introduced at or before Emacs version 22.1.
Source Code
;; Defined in /usr/src/emacs/lisp/files.el.gz
(defvar magic-fallback-mode-alist
`((image-type-auto-detected-p . image-mode)
("\\(PK00\\)?[P]K\003\004" . archive-mode) ; zip
;; The < comes before the groups (but the first) to reduce backtracking.
;; TODO: UTF-16 <?xml may be preceded by a BOM 0xff 0xfe or 0xfe 0xff.
;; We use [ \t\r\n] instead of `\\s ' to make regex overflow less likely.
(,(let* ((incomment-re "\\(?:[^-]\\|-[^-]\\)")
(comment-re (concat "\\(?:!--" incomment-re "*-->[ \t\r\n]*<\\)")))
(concat "\\(?:<\\?xml[ \t\r\n]+[^>]*>\\)?[ \t\r\n]*<"
comment-re "*"
"\\(?:!DOCTYPE[ \t\r\n]+[^>]*>[ \t\r\n]*<[ \t\r\n]*" comment-re "*\\)?"
"[Hh][Tt][Mm][Ll]"))
. mhtml-mode)
("<![Dd][Oo][Cc][Tt][Yy][Pp][Ee][ \t\r\n]+[Hh][Tt][Mm][Ll]" . mhtml-mode)
;; These two must come after html, because they are more general:
("<\\?xml " . xml-mode)
(,(let* ((incomment-re "\\(?:[^-]\\|-[^-]\\)")
(comment-re (concat "\\(?:!--" incomment-re "*-->[ \t\r\n]*<\\)")))
(concat "[ \t\r\n]*<" comment-re "*!DOCTYPE "))
. sgml-mode)
("\320\317\021\340\241\261\032\341" . doc-view-mode-maybe) ; Word documents 1997-2004
("%!PS" . ps-mode)
("# xmcd " . conf-unix-mode))
"Like `magic-mode-alist' but has lower priority than `auto-mode-alist'.
Each element looks like (REGEXP . FUNCTION) or (MATCH-FUNCTION . FUNCTION).
After visiting a file, if REGEXP matches the text at the beginning of the
buffer (case-sensitively), or calling MATCH-FUNCTION returns non-nil,
`normal-mode' will call FUNCTION, provided that `magic-mode-alist' and
`auto-mode-alist' have not specified a mode for this file.
If FUNCTION is nil, then it is not called.")