Function: org--open-file-format-command

org--open-file-format-command is a byte-compiled function defined in org.el.gz.

Signature

(org--open-file-format-command MAILCAP-COMMAND FILE LINK MATCH-DATA)

Documentation

Format MAILCAP-COMMAND to launch viewer for the FILE.

MAILCAP-COMMAND may be an entry from the org-file-apps list or viewer field from mailcap file loaded to mailcap-mime-data. See "RFC
1524. A User Agent Configuration Mechanism For Multimedia Mail Format
Information" (URL https://www.rfc-editor.org/rfc/rfc1524.html) for details, man page mailcap(5) for brief summary, and Info node
(emacs-mime) mailcap for specific related to Emacs. Only a part of
mailcap specification is supported.

The following substitutions are interpolated in the MAILCAP-COMMAND string:

- "%s" to FILE name passed through
  convert-standard-filename, so it must be absolute path.

- "%1" to "%9" groups from MATCH-DATA found in the LINK string by
  the regular expression in the key part of the org-file-apps entry.
  (performed by caller). Not recommended, consider a lisp function
  instead of a shell command. For example, the following link in an
  Org file

       <file:///usr/share/doc/bash/bashref.pdf::#Redirections::allocate a file>

   may be handled by an org-file-apps entry like

       ("\\\\.pdf\\\\(?:\\\\.[gx]z\\\\|\\\\.bz2\\\\)?::\\\\(#[^:]+\\\\)::\\\\(.+\\\\)\\\\\\='"
        . "okular --find %2 %s%1")

Use backslash "\\" to quote percent "%" or any other character including backslash itself.

In addition, each argument is passed through shell-quote-argument, so quotes around substitutions should not be used. For compliance with mailcap files shipped e.g. in Debian GNU/Linux, single or double quotes around substitutions are stripped. It deviates from mailcap specification that requires file name to be safe for shell and for the application.

Source Code

;; Defined in /usr/src/emacs/lisp/org/org.el.gz
(defun org--open-file-format-command
    (mailcap-command file link match-data)
  "Format MAILCAP-COMMAND to launch viewer for the FILE.

MAILCAP-COMMAND may be an entry from the `org-file-apps' list or viewer
field from mailcap file loaded to `mailcap-mime-data'.  See \"RFC
1524.  A User Agent Configuration Mechanism For Multimedia Mail Format
Information\" (URL `https://www.rfc-editor.org/rfc/rfc1524.html') for
details, man page `mailcap(5)' for brief summary, and Info node
`(emacs-mime) mailcap' for specific related to Emacs.  Only a part of
mailcap specification is supported.

The following substitutions are interpolated in the MAILCAP-COMMAND
string:

- \"%s\" to FILE name passed through
  `convert-standard-filename', so it must be absolute path.

- \"%1\" to \"%9\" groups from MATCH-DATA found in the LINK string by
  the regular expression in the key part of the `org-file-apps' entry.
  (performed by caller).  Not recommended, consider a lisp function
  instead of a shell command.  For example, the following link in an
  Org file

       <file:///usr/share/doc/bash/bashref.pdf::#Redirections::allocate a file>

   may be handled by an `org-file-apps' entry like

       (\"\\\\.pdf\\\\(?:\\\\.[gx]z\\\\|\\\\.bz2\\\\)?::\\\\(#[^:]+\\\\)::\\\\(.+\\\\)\\\\\\='\"
        . \"okular --find %2 %s%1\")

Use backslash \"\\\" to quote percent \"%\" or any other character
including backslash itself.

In addition, each argument is passed through `shell-quote-argument',
so quotes around substitutions should not be used.  For compliance
with mailcap files shipped e.g. in Debian GNU/Linux, single or double
quotes around substitutions are stripped.  It deviates from mailcap
specification that requires file name to be safe for shell and for the
application."
  (let ((spec (list (cons ?s  (convert-standard-filename file))))
        (ngroups (min 9 (- (/ (length match-data) 2) 1))))
    (when (> ngroups 0)
      (set-match-data match-data)
      (dolist (i (number-sequence 1 ngroups))
        (push (cons (+ ?0 i) (match-string-no-properties i link)) spec)))
    (replace-regexp-in-string
     (rx (or (and "\\" (or (group anything) string-end))
             (and (optional (group (any "'\"")))
                  "%"
                  (or (group anything) string-end)
                  (optional (group (backref 2))))))
     (lambda (fmt)
       (let* ((backslash (match-string-no-properties 1 fmt))
              (key (match-string 3 fmt))
              (value (and key (alist-get (string-to-char key) spec))))
         (cond
          (backslash)
          (value (let ((quot (match-string 2 fmt))
                       (subst (shell-quote-argument value)))
                   ;; Remove quotes around the file name - we use
                   ;; `shell-quote-argument'.
                   (if (match-string 4 fmt)
                       subst
                     (concat quot subst))))
          (t (error "Invalid format `%s'" fmt)))))
     mailcap-command nil 'literal)))