这是一个多合一的解决方案。它将从Rnw创建并显示PDF。
具体来说，它将：
- 保存Rnw缓冲区并进行编织，
- 将给定的LaTeX引擎应用于生成的TeX文件，
- 识别BibTeX引擎可执行文件（例如biber，bibtex8），
- 如果bib文件比TeX文件新，请在TeX文件上运行BibTeX引擎，
- 再次运行LaTeX，6在指定的查看器中打开生成的PDF。
如果上述步骤之一失败，该过程将尝试退出并提供提示性消息。
如有必要，将打开一个R实例，或者使用当前实例显示编织过程。
LaTeX输出将发送到“ TeX-output”缓冲区，如果发生编译错误，该缓冲区也会弹出。
用法
Meta- x knit-me创建和查看PDF。
Meta- x knit-me-clear删除中间的LaTeX文件和knit-me。
参考书目需要“ biblatex”软件包，即：
\usepackage[
options...
backend=ENGINE,
]{biblatex}
\addbibresource{foo.bib}
通过解析关键字bibtex，biber获得了bib引擎的名称（例如）backend。
\addbibresource解析命令以获取书目文件：如果foo.bib比TeX文件新，则运行bib引擎。在这方面，\addbibresource如果有很多命令，则仅考虑第一个命令。
定制
要实际查看PDF，请使用以下命令设置查看器的可执行路径：
(setq pdf-viewer "path/to/pdf-viewer")
可能使用诸如SumatraPDF的查看器，该查看器在重新编译时会自动更新PDF，并且不会阻止打开的文件阻止新的编译。
默认的LaTeX引擎为pdflatex（假定在当前路径中）。自定义：
(setq latex-engine "newengine"
latex-args "--option-1 --option-2")
当然，您可能需要绑定knit-me并绑定knit-me-clear一些方便的键。
笔记
在Windows MiKTeX（带有biber和bibtex8后端）以及GNU Emacs 25.1.1中进行了测试。
Elisp代码
;; (require 'ess-site) ; assumed in your init file
(defun knit-me-clear ()
"Delete intermediate LaTeX files and run `knkt-me'.
These are based on extensions .aux, .blg, .out, .run.xml, .bbl, .log, -blx.bib"
(interactive)
(check-Rnw)
(let
((file)
(stem (file-name-sans-extension (buffer-file-name))))
(dolist (elt
(list ".aux" ".blg" ".out" ".run.xml" ".bbl" ".log" "-blx.bib"))
(setq file (concat stem elt))
(if (file-exists-p file) (delete-file file))))
(knit-me))
(defun knit-me ()
"Knit->LaTeX-engine->bibtex-engine->LaTeX-engine->View.
Default LaTeX engine is \"pdflatex\" and can be customised with `latex-engine';
default LaTeX arguments are set to nil and can be customised with `latex-args';
default PDF viewer is set to nil and can be customised with `pdf-viewer'.
Bibliography must be set via \"biblatex\" LaTeX package.
Bibliography engine is obtained from \"backend\" option in \"biblatex\" package.
A reference LaTeX bib file is obtained from the first LaTeX command \"\addbibresource{foo.bib}\".
The biblatex-engine is run if the bib file is newer of the TeX file.
If there are multiple \"\addbibresource\" only the first will be used to decide whether to run the biblatex-engine."
(interactive)
;; Default values
(defvar pdf-viewer nil)
(defvar latex-engine "pdflatex")
(defvar latex-args nil)
(check-Rnw)
;;If 1 R-proc found, associate it with buffer;
;;if many found, ask to choose one; if none found, launch and associate
(ess-force-buffer-current "Process to use: ")
;;Save Rnw buffer
(save-buffer)
(let*
(;;Set file paths
(pathstem (file-name-sans-extension (buffer-file-name)))
(namestem (file-name-nondirectory pathstem))
(cur-dir (file-name-directory pathstem))
(rnw-name (concat namestem ".Rnw"))
(tex-name (concat namestem ".tex"))
;;Create LaTeX commmand
(latex-args (concat latex-args " " namestem))
(latex-cmd (concat latex-engine " " latex-args))
;;Create knit commmand
(knit-cmd (format "require(knitr); setwd('%s'); knit('%s')" cur-dir rnw-name))
;;Get R buffer proc
(r-proc (ess-get-process))
(r-buf (ess-get-process-buffer))
;;TeX executable process and bibtex engine/file
(tex-proc)
(tex-buf)
(bibfile (bib-getfile))
(bibengine (bib-getengine))
(bibfile-updated
(file-newer-than-file-p
(concat cur-dir (file-name-nondirectory bibfile) ".bib") (concat pathstem ".tex")))
;;Command success
(success nil)
(error-msg "")
)
(setq default-directory cur-dir)
;; Exit on error
(catch 'exit-func
;;Check bibtex file and engine
(when (not bibfile)
(setq error-msg (bib-getfile t))
(throw 'exit-func nil))
(when (not bibengine)
(setq error-msg (bib-getengine t))
(throw 'exit-func nil))
;; Biber wants .bib
(let ((fail (and (string= bibengine "biber")
(string= (file-name-nondirectory bibfile) (file-name-base bibfile)))))
(setq success (not fail)))
(when (not success)
(setq error-msg
(format "biber wants \\addbibresource{%s%s}" (file-name-base bibfile) ".bib"))
(throw 'exit-func nil))
;; Knitting
(switch-to-buffer-other-window r-buf)
(message knit-cmd)
(ess-eval-linewise knit-cmd nil t nil t)
;; Foll. 3 lines are an alternative to ess-eval
;; (inferior-ess-mark-as-busy r-proc) ; knit immediately after this line
;; (process-send-string r-proc (format "cat(\"%s\");%s\n" knit-cmd knit-cmd)) ; real
;; (ess-wait-for-process r-proc nil)
;; Check for knitting results
(with-current-buffer r-buf
;; Parse last 3 lines
(let ((beg) (end) (out))
(goto-char (point-max))
(setq end (point))
(forward-line -3)
(setq beg (point))
(setq out (buffer-substring-no-properties beg end))
;; Knitting successful?
(setq success "output file: %s\n\n[1] \"%s\"\n> ")
(setq success (string= (format success tex-name tex-name) out))))
(when (not success)
(setq error-msg (concat "Unable to knit " rnw-name))
(throw 'exit-func nil))
;; First LaTeXing
(setq tex-buf (get-buffer-create "TeX-output")) ; Create output buffer or use existing
(with-current-buffer tex-buf
(buffer-disable-undo)
(erase-buffer))
(message "1st latex ...")
(send-r-mess (format "Starting LaTeX (see \"%s\")" (buffer-name tex-buf)))
(send-r-mess latex-cmd)
(setq success (= 0 (call-process latex-engine nil tex-buf t latex-args)))
(goto-char (point-max))
;; Check 1st LaTeX results
(when (not success)
(setq error-msg (concat "Unable to LaTeX " namestem))
(switch-to-buffer-other-window tex-buf)
(other-window 1)
(throw 'exit-func nil))
;; Run bibtex engine
(when bibfile-updated
(message "biblatex ...")
(send-r-mess (concat bibengine " " namestem))
(setq success (= 0 (call-process bibengine nil tex-buf t namestem)))
(goto-char (point-max))
;; Check bibtex results
(when (not success)
(setq error-msg (concat "Unable to " bibengine " " namestem))
(switch-to-buffer-other-window tex-buf)
(other-window 1)
(throw 'exit-func nil)))
;; Second LaTeXing
(message "2nd latex ...")
(send-r-mess latex-cmd)
(setq success (= 0 (call-process latex-engine nil tex-buf t latex-args)))
(goto-char (point-max))
;; Check 2nd LaTeX results
(when (not success)
(setq error-msg (concat "Unable to LaTeX " pathstem))
(switch-to-buffer-other-window tex-buf)
(other-window 1)
(throw 'exit-func nil))
;; View
(if (not pdf-viewer) (throw 'exit-func nil))
(send-r-mess "...and now the viewer")
(goto-char (point-max))
(setq success (file-exists-p pdf-viewer))
(when (not success)
(setq error-msg (concat "Can\\'t find executable " pdf-viewer))
(throw 'exit-func nil))
;; If you need viewer console output, use "(start-process "pdf-viewer" tex-buf ...";
;; but you block tex-buf buffer till the viewer is open
(start-process "pdf-viewer" nil pdf-viewer (concat namestem ".pdf")))
(if success
(if bibfile-updated (message (concat "Updated to " (file-name-nondirectory bibfile))))
(message error-msg)
(send-r-mess error-msg))))
(defun bib-getfile(&optional show-messages)
"Check if 'addbibresource' command and related file exist.
If found, return .bib file full path, else:
if SHOW-MESSAGES is nil return nil, if SHOW-MESSAGES is non-nil return related error."
(save-excursion
(goto-char (point-min))
(re-search-forward "\\\\addbibresource{\\(.+\\)}" nil t))
(let ((fmatch (match-string-no-properties 1))
(success nil)
mess)
(cond
((not fmatch) (setq mess "Missing \\addbibresource command."))
((not (file-exists-p (concat (file-name-sans-extension fmatch) ".bib")))
(setq mess (concat "Missing file: " fmatch ".bib")))
;; if no problem, sucess=message=bib-file-path
(t (setq mess (concat (file-name-directory (buffer-file-name)) fmatch)
success mess)))
(if show-messages mess success)))
(defun bib-getengine(&optional show-messages)
"Find biblatex engine.
If found, engine name, else:
if SHOW-MESSAGES is nil return nil, if SHOW-MESSAGES is non-nil return related error."
(save-excursion
(goto-char (point-min))
(let ((pack (re-search-forward "\\\\usepackage *\\(\\[[^]]*\\)\\] *{ *biblatex *}" nil t))
(bend nil)
mess)
(when pack (setq pack (match-string-no-properties 1)))
(when (and pack
(string-match "[^[:alpha:]]+backend *= *\\([^, \n]+\\)" pack))
(setq bend (match-string 1 pack)))
(cond
((not pack) (setq mess "Missing biblatex package command."))
((not bend) (setq mess "Missing biblatex backend."))
;; if no problem, sucess=message=bib-file-path
(t (setq mess bend)))
(if show-messages mess bend))))
(defun send-r-mess (mess)
"Just send MESS at the end of R console buffer"
(process-send-string (ess-get-process)
(format "cat('%s\\n')\n" mess)))
(defun check-Rnw ()
"Give error if `ess-dialect' is not \"R\""
(if (not (string= "R" ess-dialect))
(error "Not an Rnw buffer")))
rmarkdown::render（通过shell-command）键绑定buffer-file-name，这将在另一个窗口中更新pdf。