19 KiB
The Library of Babel
- Introduction
- Simple
- File I/O
- Plotting code
- Org reference
- Tables
- Misc
- GANTT Charts
- Available languages
Introduction
The Library of Babel is an extensible collection of ready-made and
easily-shortcut-callable source-code blocks for handling common tasks.
Org-babel comes pre-populated with the source-code blocks located in
this file. It is possible to add source-code blocks from any org-mode
file to the library by calling (org-babel-lob-ingest
"path/to/file.org").
This file is included in worg mainly less for viewing through the web interface, and more for contribution through the worg git repository. If you have code snippets that you think others may find useful please add them to this file and contribute them to worg.
The raw Org-mode text of this file can be downloaded at library-of-babel.org
Simple
A collection of simple utility functions:
inputFile I/O
Reading and writing files
Read the contents of the file at file. The :results vector and
:results scalar header arguments can be used to read the contents of
file as either a table or a string.
(if (string= format "csv")
(with-temp-buffer
(org-table-import (expand-file-name file) nil)
(org-table-to-lisp))
(with-temp-buffer
(insert-file-contents (expand-file-name file))
(buffer-string)))
Write data to a file at file. If data is a list, then write it
as a table in traditional Org-mode table syntax.
(flet ((echo (r) (if (stringp r) r (format "%S" r))))
(with-temp-file file
(case (and (listp data)
(or ext (intern (file-name-extension file))))
('tsv (insert (orgtbl-to-tsv data '(:fmt echo))))
('csv (insert (orgtbl-to-csv data '(:fmt echo))))
(t (org-babel-insert-result data)))))
nilRemote files
json
Read local or remote file in json format into emacs-lisp objects.
(require 'json)
(cond
(file
(with-temp-filebuffer file
(goto-char (point-min))
(json-read)))
(url
(require 'w3m)
(with-temp-buffer
(w3m-retrieve url)
(goto-char (point-min))
(json-read))))Google docs
The following code blocks make use of the googlecl Google command line tool. This tool provides functionality for accessing Google services from the command line, and the following code blocks use googlecl for reading from and writing to Google docs with Org-mode code blocks.
Read a document from Google docs
The google command seems to be throwing "Moved Temporarily" errors
when trying to download textual documents, but this is working fine
for spreadsheets.
(let* ((file (concat title "." format))
(cmd (format "google docs get --format %S --title %S" format title)))
(message cmd) (message (shell-command-to-string cmd))
(prog1 (if (string= format "csv")
(with-temp-buffer
(org-table-import (shell-quote-argument file) '(4))
(org-table-to-lisp))
(with-temp-buffer
(insert-file-contents (shell-quote-argument file))
(buffer-string)))
(delete-file file)))
For example, a line like the following can be used to read the
contents of a spreadsheet named num-cells into a table.
#+call: gdoc-read(title="num-cells"")
A line like the following can be used to read the contents of a document as a string.
#+call: gdoc-read(title="loremi", :format "txt")
Write a document to a Google docs
Write data to a google document named title. If data is tabular
it will be saved to a spreadsheet, otherwise it will be saved as a
normal document.
(let* ((format (if (listp data) "csv" "txt"))
(tmp-file (make-temp-file "org-babel-google-doc" nil (concat "." format)))
(cmd (format "google docs upload --title %S %S" title tmp-file)))
(with-temp-file tmp-file
(insert
(if (listp data)
(orgtbl-to-csv
data '(:fmt (lambda (el) (if (stringp el) el (format "%S" el)))))
(if (stringp data) data (format "%S" data)))))
(message cmd)
(prog1 (shell-command-to-string cmd) (delete-file tmp-file)))example usage
#+name: fibs
#+begin_src emacs-lisp :var n=8
(flet ((fib (m) (if (< m 2) 1 (+ (fib (- m 1)) (fib (- m 2))))))
(mapcar (lambda (el) (list el (fib el))) (number-sequence 0 (- n 1))))
#+end_src
#+call: gdoc-write(title="fibs", data=fibs(n=10))
Plotting code
R
Plot column 2 (y axis) against column 1 (x axis). Columns 3 and beyond, if present, are ignored.
plot(data)| 1 | 2 |
| 2 | 4 |
| 3 | 9 |
| 4 | 16 |
| 5 | 25 |
nil
Gnuplot
Org reference
Headline references
(save-excursion
(when file (get-file-buffer file))
(org-open-link-from-string (org-make-link-string headline))
(save-restriction
(org-narrow-to-subtree)
(buffer-string)))Tables
LaTeX Table Export
booktabs
This source block can be used to wrap a table in the latex booktabs
environment. The source block adds a toprule and bottomrule (so
don't use hline at the top or bottom of the table). The hline
after the header is replaced with a midrule.
Note that this function bypasses the Org-mode LaTeX exporter and calls
orgtbl-to-generic to create the output table. This means that the
entries in the table are not translated from Org-mode to LaTeX.
It takes the following arguments – all but the first two are optional.
| arg | description |
|---|---|
| table | a reference to the table |
| align | alignment string |
| env | optional environment, default to "tabular" |
| width | optional width specification string |
(flet ((to-tab (tab)
(orgtbl-to-generic
(mapcar (lambda (lis)
(if (listp lis)
(mapcar (lambda (el)
(if (stringp el)
el
(format "%S" el))) lis)
lis)) tab)
(list :lend " \\\\" :sep " & " :hline "\\hline"))))
(org-fill-template
"
\\begin{%env}%width%align
\\toprule
%table
\\bottomrule
\\end{%env}\n"
(list
(cons "env" (or env "table"))
(cons "width" (if width (format "{%s}" width) ""))
(cons "align" (if align (format "{%s}" align) ""))
(cons "table"
;; only use \midrule if it looks like there are column headers
(if (equal 'hline (second table))
(concat (to-tab (list (first table)))
"\n\\midrule\n"
(to-tab (cddr table)))
(to-tab table))))))longtable
This block can be used to wrap a table in the latex longtable
environment, it takes the following arguments – all but the first two
are optional.
| arg | description |
|---|---|
| table | a reference to the table |
| align | optional alignment string |
| width | optional width specification string |
| hline | the string to use as hline separator, defaults to "\\hline" |
| head | optional "head" string |
| firsthead | optional "firsthead" string |
| foot | optional "foot" string |
| lastfoot | optional "lastfoot" string |
(org-fill-template
"
\\begin{longtable}%width%align
%firsthead
%head
%foot
%lastfoot
%table
\\end{longtable}\n"
(list
(cons "width" (if width (format "{%s}" width) ""))
(cons "align" (if align (format "{%s}" align) ""))
(cons "firsthead" (if firsthead (concat firsthead "\n\\endfirsthead\n") ""))
(cons "head" (if head (concat head "\n\\endhead\n") ""))
(cons "foot" (if foot (concat foot "\n\\endfoot\n") ""))
(cons "lastfoot" (if lastfoot (concat lastfoot "\n\\endlastfoot\n") ""))
(cons "table" (orgtbl-to-generic
(mapcar (lambda (lis)
(if (listp lis)
(mapcar (lambda (el)
(if (stringp el)
el
(format "%S" el))) lis)
lis)) table)
(list :lend " \\\\" :sep " & " :hline hline)))))booktabs-notes
This source block builds on /mirror/org-mode/src/commit/cab6718d4b41f1fb9127384ddeac33f3afbec338/doc/booktabs. It accepts two additional arguments, both of which are optional.
| arg | description |
|---|---|
| notes | an org-mode table with footnotes |
| lspace | if non-nil, insert addlinespace after bottomrule |
An example footnote to the arguments table specifies the column
span. Note the use of LaTeX, rather than Org-mode, markup.
| μlticolumn{2}{l}{This is a footnote to the \emph{arguments} table.} |
(flet ((to-tab (tab)
(orgtbl-to-generic
(mapcar (lambda (lis)
(if (listp lis)
(mapcar (lambda (el)
(if (stringp el)
el
(format "%S" el))) lis)
lis)) tab)
(list :lend " \\\\" :sep " & " :hline "\\hline"))))
(org-fill-template
"
\\begin{%env}%width%align
\\toprule
%table
\\bottomrule%spacer
%notes
\\end{%env}\n"
(list
(cons "env" (or env "table"))
(cons "width" (if width (format "{%s}" width) ""))
(cons "align" (if align (format "{%s}" align) ""))
(cons "spacer" (if lspace "\\addlinespace" ""))
(cons "table"
;; only use \midrule if it looks like there are column headers
(if (equal 'hline (second table))
(concat (to-tab (list (first table)))
"\n\\midrule\n"
(to-tab (cddr table)))
(to-tab table)))
(cons "notes" (if notes (to-tab notes) ""))
)))Elegant lisp for transposing a matrix
| 1 | 2 | 3 |
| 4 | 5 | 6 |
(apply #'mapcar* #'list table)| 1 | 4 |
| 2 | 5 |
| 3 | 6 |
Convert every element of a table to a string
| 1 | 2 | 3 |
| a | b | c |
(defun all-to-string (tbl)
(if (listp tbl)
(mapcar #'all-to-string tbl)
(if (stringp tbl)
tbl
(format "%s" tbl))))
(all-to-string tbl) (mapcar (lambda (row) (mapcar (lambda (cell) (stringp cell)) row)) tbl)| nil | nil | nil |
| t | t | t |
(mapcar (lambda (row) (mapcar (lambda (cell) (stringp cell)) row)) tbl)| t | t | t |
| t | t | t |
Misc
File-specific Version Control logging
This function will attempt to retrieve the entire commit log for the file associated with the current buffer and insert this log into the export. The function uses the Emacs VC commands to interface to the local version control system, but has only been tested to work with Git. 'limit' is currently unsupported.
;; Most of this code is copied from vc.el vc-print-log
(require 'vc)
(when (vc-find-backend-function
(vc-backend (buffer-file-name (get-buffer buf))) 'print-log)
(let ((limit -1)
(vc-fileset nil)
(backend nil)
(files nil))
(with-current-buffer (get-buffer buf)
(setq vc-fileset (vc-deduce-fileset t)) ; FIXME: Why t? --Stef
(setq backend (car vc-fileset))
(setq files (cadr vc-fileset)))
(with-temp-buffer
(let ((status (vc-call-backend
backend 'print-log files (current-buffer))))
(when (and (processp status) ; Make sure status is a process
(= 0 (process-exit-status status))) ; which has not terminated
(while (not (eq 'exit (process-status status)))
(sit-for 1 t)))
(buffer-string)))))Trivial python code blocks
aa + bArithmetic
(+ a b) (- a b) (* a b) (/ a b)GANTT Charts
The elispgantt source block was sent to the mailing list by Eric
Fraga. It was modified slightly by Tom Dye.
(let ((dates "")
(entries (nthcdr 2 table))
(milestones "")
(nmilestones 0)
(ntasks 0)
(projecttime 0)
(tasks "")
(xlength 1))
(message "Initial: %s\n" table)
(message "Entries: %s\n" entries)
(while entries
(let ((entry (first entries)))
(if (listp entry)
(let ((id (first entry))
(type (nth 1 entry))
(label (nth 2 entry))
(task (nth 3 entry))
(dependencies (nth 4 entry))
(start (nth 5 entry))
(duration (nth 6 entry))
(end (nth 7 entry))
(alignment (nth 8 entry)))
(if (> start projecttime) (setq projecttime start))
(if (string= type "task")
(let ((end (+ start duration))
(textposition (+ start (/ duration 2)))
(flush ""))
(if (string= alignment "left")
(progn
(setq textposition start)
(setq flush "[left]"))
(if (string= alignment "right")
(progn
(setq textposition end)
(setq flush "[right]"))))
(setq tasks
(format "%s \\gantttask{%s}{%s}{%d}{%d}{%d}{%s}\n"
tasks label task start end textposition flush))
(setq ntasks (+ 1 ntasks))
(if (> end projecttime)
(setq projecttime end)))
(if (string= type "milestone")
(progn
(setq milestones
(format
"%s \\ganttmilestone{$\\begin{array}{c}\\mbox{%s}\\\\ \\mbox{%s}\\end{array}$}{%d}\n"
milestones label task start))
(setq nmilestones (+ 1 nmilestones)))
(if (string= type "date")
(setq dates (format "%s \\ganttdateline{%s}{%d}\n"
dates label start))
(message "Ignoring entry with type %s\n" type)))))
(message "Ignoring non-list entry %s\n" entry)) ; end if list entry
(setq entries (cdr entries)))) ; end while entries left
(format "\\pgfdeclarelayer{background}
\\pgfdeclarelayer{foreground}
\\pgfsetlayers{background,foreground}
\\renewcommand{\\ganttprojecttime}{%d}
\\renewcommand{\\ganttntasks}{%d}
\\noindent
\\begin{tikzpicture}[y=-0.75cm,x=0.75\\textwidth]
\\begin{pgfonlayer}{background}
\\draw[very thin, red!10!white] (0,1+\\ganttntasks) grid [ystep=0.75cm,xstep=1/\\ganttprojecttime] (1,0);
\\draw[\\ganttdatelinecolour] (0,0) -- (1,0);
\\draw[\\ganttdatelinecolour] (0,1+\\ganttntasks) -- (1,1+\\ganttntasks);
\\end{pgfonlayer}
%s
%s
%s
\\end{tikzpicture}" projecttime ntasks tasks milestones dates))Available languages
From Org's core
| Language | Identifier | Language | Identifier |
|---|---|---|---|
| Asymptote | asymptote | Awk | awk |
| Emacs Calc | calc | C | C |
| C++ | C++ | Clojure | clojure |
| CSS | css | ditaa | ditaa |
| Graphviz | dot | Emacs Lisp | emacs-lisp |
| gnuplot | gnuplot | Haskell | haskell |
| Javascript | js | LaTeX | latex |
| Ledger | ledger | Lisp | lisp |
| Lilypond | lilypond | MATLAB | matlab |
| Mscgen | mscgen | Objective Caml | ocaml |
| Octave | octave | Org-mode | org |
| Perl | perl | ||
| Plantuml | plantuml | Python | python |
| R | R | Ruby | ruby |
| Sass | sass | Scheme | scheme |
| GNU Screen | screen | shell | sh |
| SQL | sql | SQLite | sqlite |
From Org's contrib/babel/langs
- ob-oz.el, by Torsten Anders and Eric Schulte
- ob-fomus.el, by Torsten Anders