How to output Bash heredoc blocks using PHP heredoc

Question

I need to display a bash script on a webpage without any formatting.

The bash script uses standard 'here document' blocks. When I try to output the script using the PHP heredoc function, it cuts off the output when it encounters a '<<' sub-string. I thought the PHP heredoc function did not require escaping.

How do I output this script correctly?

<?php

$string = $_GET["string"];

$bashscript = <<<MYMARKER
<pre>

#!/bin/sh
rm /tmp/blue.sh
cat <<INSTALL > /tmp/blue.sh
#!/bin/sh
cd /tmp
mkdir output
cd output
cat <<EOF > interface.conf
remote $string
EOF
INSTALL

</pre>
MYMARKER;

echo $bashscript;

?>

The output I get on the page is

#!/bin/sh
rm /tmp/blue.sh
cat < /tmp/blue.sh
#!/bin/sh
cd /tmp
mkdir output
cd output
cat < interface.conf
remote 
EOF
INSTALL

dan-lee · Accepted Answer · 2013-02-19 16:29:01Z

3

That's because <INSTALL > and <EOF > are interpreted as tags in your browser (unrecognized though). Open it with right click -> view source and you'll see it right. Just move out the <pre> and use htmlspecialchars() to display it correctly:

$bashscript = <<<MYMARKER
... everything without the <pre> tags ...
MYMARKER;

echo '<pre>'.htmlspecialchars($bashscript).'</pre>';

edited Feb 19, 2013 at 16:29

answered Feb 19, 2013 at 16:23

dan-lee

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2 Comments

Michelle Over a year ago

Thanks, I should have picked that up, time for a break!

dan-lee Over a year ago

Happens to us all; glad I could help

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