How to word wrap within code blocks

Question

I'm trying to get the formatting right for an org-mode file being exported to pdf. I set 'org-startup-truncated' to nil and that has resolved my word wrapping issues for non code blocks. But I cannot figure out how to set word wrapping or preventing lines from getting truncated within code blocks. Is there a way to accomplish this?

Here is a screenshot of the relevant pdf section. Notice the variable 'buffer' running off of the page.

Here is the text from my org file:

#+BEGIN_SRC python
#!/usr/bin/python
import socket

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

#buffer = 'Aa0Aa1Aa2Aa3Aa4Aa5Aa6Aa7Aa8Aa9Ab0Ab1Ab2Ab3Ab4Ab5Ab6Ab7Ab8Ab9Ac0Ac1Ac2Ac3Ac4Ac5Ac6Ac7Ac8Ac9Ad0Ad1Ad2Ad3Ad4Ad5Ad6Ad7Ad8Ad9Ae0Ae1Ae2Ae3Ae4Ae5Ae6Ae7$'
#+END_SRC

Answer 1

Org-mode files get exported to PDF with the document preparation system LaTeX.

Code blocks by default get exported into verbatim environment which does not have line wrapping. You can see this by visiting the .tex file created in the same folder when you export; your code blocks should look like this:

\begin{verbatim}
import socket
# etc
\end{verbatim}

You could tell Org-mode to use a different environment for code blocks.

listings

A commonly used environment for source code is lstlisting, provided by the LaTeX package listings. To get Org-mode to use it, add it to org-latex-packages-alist and set the variable org-latex-listings to t:

(add-to-list 'org-latex-packages-alist '("" "listings" nil))
(setq org-latex-listings t)

to then get listings to wrap, the breaklines=true option needs to be supplied to listings. Org-mode can do this:

(setq org-latex-listings-options '(("breaklines" "true")))

This will work for normal use, however your MWE will fail because of the long variable value which does not contain spaces; breaklines does not break lines in the middle of words.

Breaking lines in the middle of words is not trivial since it could result in unwanted line breaks elsewhere. See

• How to deal with very long lines that do not contain spaces
• listings: Break long hexadecimal in multiple lines
• Automatic line breaks of long numbers in listings
• Listings - break on whitespace+

Here is one way to make your MWE work, using Werner’s literate one-to-one mapping of numerals:

(setq org-latex-listings-options '(("breaklines" "true")
                                   ("literate" "{0}{0}{1}%
           {1}{1}{1}%
           {2}{2}{1}%
           {3}{3}{1}%
           {4}{4}{1}%
           {5}{5}{1}%
           {6}{6}{1}%
           {7}{7}{1}%
           {8}{8}{1}%
           {9}{9}{1}%
    ")))

minted

Another popular LaTeX package for this purpose is minted. In addition to installing the package you will need to install python and the python-based syntax highlighter pygments. The basic configuration to get Org-mode to then use minted is described in another SE question.

The package documentation describes the available options. One approach could be to use breaklines and breakanywhere.

(setq org-latex-minted-options '(("breaklines" "true")
                                 ("breakanywhere" "true")))

---

As an aside, I don’t see how setting org-startup-truncated could have changed anything about how the document is exported. This only affects truncate-lines in the buffer. LaTeX wraps the lines for you whether or not they are truncated in the buffer.