How to escape the ‘#’ comment character within Ansible lineinfile module

ansibleescapingyaml

How can I escape characters in Ansible's lineinfile module?

Here's the line I want to insert on the server:

EMAIL='hi@demo.com' # Server notification email address enter only 1 address

But when I try the following, Ansible refuses to parse it due to YAML errors:

line="EMAIL='{{ email_address }}' # Server notification email address enter only 1 address"

I'm guessing it's because I have a strange combination of double quotes, single quotes, equal character and pound character.

Best Answer

The problem indeed is the # in your string - for whatever reason.

Though you can easily prevent the parsing error by using this trick:

line="EMAIL='{{ email_address }}' {{ '#' }} Server notification email address enter only 1 address"

Use `\r` instead of `\n`.

Substituting by \n inserts a null character into the text. To get a newline, use \r. When searching for a newline, you’d still use \n, however. This asymmetry is due to the fact that \n and \r do slightly different things:

\n matches an end of line (newline), whereas \r matches a carriage return. On the other hand, in substitutions \n inserts a null character whereas \r inserts a newline (more precisely, it’s treated as the input CR). Here’s a small, non-interactive example to illustrate this, using the Vim command line feature (in other words, you can copy and paste the following into a terminal to run it). xxd shows a hexdump of the resulting file.

echo bar > test
(echo 'Before:'; xxd test) > output.txt
vim test '+s/b/\n/' '+s/a/\r/' +wq
(echo 'After:'; xxd test) >> output.txt
more output.txt

Before:
0000000: 6261 720a                                bar.
After:
0000000: 000a 720a                                ..r.

In other words, \n has inserted the byte 0x00 into the text; \r has inserted the byte 0x0a.

Html – How to escape ampersands in XML so they are rendered as entities in HTML

When your XML contains &amp;, this will result in the text &.

When you use that in HTML, that will be rendered as &.

Best Answer

Related Solutions

How to replace a character by a newline in Vim

Use \r instead of \n.

Html – How to escape ampersands in XML so they are rendered as entities in HTML

Related Topic

Use `\r` instead of `\n`.