Info Catalog org: Extracting source code org: Working With Source Code org: Library of Babel

org: Evaluating code blocks

 
 14.5 Evaluating code blocks
 ===========================
 
 Code blocks can be evaluated(1) and the results of evaluation optionally
 placed in the Org mode buffer.  The results of evaluation are placed
 following a line that begins by default with ‘#+RESULTS’ and optionally
 a cache identifier and/or the name of the evaluated code block.  The
 default value of ‘#+RESULTS’ can be changed with the customizable
 variable ‘org-babel-results-keyword’.
 
    By default, the evaluation facility is only enabled for Lisp code
 blocks specified as ‘emacs-lisp’.  However, source code blocks in many
 languages can be evaluated within Org mode (see Languages for a
 list of supported languages and Structure of code blocks for
 information on the syntax used to define a code block).
 
    There are a number of ways to evaluate code blocks.  The simplest is
 to press ‘C-c C-c’ or ‘C-c C-v e’ with the point on a code block(2).
 This will call the ‘org-babel-execute-src-block’ function to evaluate
 the block and insert its results into the Org mode buffer.
 
    It is also possible to evaluate named code blocks from anywhere in an
 Org mode buffer or an Org mode table.  Live code blocks located in the
 current Org mode buffer or in the “Library of Babel” (see Library
 of Babel) can be executed.  Named code blocks can be executed with a
 separate ‘#+CALL:’ line or inline within a block of text.
 
    The syntax of the ‘#+CALL:’ line is
 
      #+CALL: <name>(<arguments>)
      #+CALL: <name>[<inside header arguments>](<arguments>) <end header arguments>
 
    The syntax for inline evaluation of named code blocks is
 
      ... call_<name>(<arguments>) ...
      ... call_<name>[<inside header arguments>](<arguments>)[<end header arguments>] ...
 
 ‘<name>’
      The name of the code block to be evaluated (see Structure of
      code blocks).
 ‘<arguments>’
      Arguments specified in this section will be passed to the code
      block.  These arguments use standard function call syntax, rather
      than header argument syntax.  For example, a ‘#+CALL:’ line that
      passes the number four to a code block named ‘double’, which
      declares the header argument ‘:var n=2’, would be written as
      ‘#+CALL: double(n=4)’.
 ‘<inside header arguments>’
      Inside header arguments are passed through and applied to the named
      code block.  These arguments use header argument syntax rather than
      standard function call syntax.  Inside header arguments affect how
      the code block is evaluated.  For example, ‘[:results output]’ will
      collect the results of everything printed to ‘STDOUT’ during
      execution of the code block.
 ‘<end header arguments>’
      End header arguments are applied to the calling instance and do not
      affect evaluation of the named code block.  They affect how the
      results are incorporated into the Org mode buffer and how the call
      line is exported.  For example, ‘:results html’ will insert the
      results of the call line evaluation in the Org buffer, wrapped in a
      ‘BEGIN_HTML:’ block.
 
      For more examples of passing header arguments to ‘#+CALL:’ lines
      see Header arguments in function calls.
 
    ---------- Footnotes ----------
 
    (1) Whenever code is evaluated there is a potential for that code to
 do harm.  Org mode provides safeguards to ensure that code is only
 evaluated after explicit confirmation from the user.  For information on
 these safeguards (and on how to disable them) see Code evaluation
 security.
 
    (2) The option ‘org-babel-no-eval-on-ctrl-c-ctrl-c’ can be used to
 remove code evaluation from the ‘C-c C-c’ key binding.
 

Info Catalog org: Extracting source code org: Working With Source Code org: Library of Babel