How to read variables from a php file in bash

Question

How do I export variables from a PHP script in Bash?

I'm writing a Bash script to read database names from config.php files of each website, and then import the database from the backup repository. I tried to use source config.php but it seems it doesn't recognize PHP variables.

Any help would be appreciated.

Answer 1

I suggest that you use the program that will "do one thing well" (Unix philosophy), in this case use PHP to parse PHP. You can do so from bash as follows:

variable1=$(php -r 'require("input.php"); echo $variable1;')
variable2=$(php -r 'require("input.php"); echo $variable2;')

You can test this with an input.php file like:

<?php
$variable1="hello";
$variable2="hello2";
?>

For an example where the php file has a return, instead see my answer at https://askubuntu.com/a/1469387/766334.

Answer 2

Building up on @Poikilos's answer:

eval "$(
  php -r '
    require("config.php");
    foreach(get_defined_vars() as $name => $var)
      if (is_string($var))
        echo "php_", $name, "=", escapeshellarg($var), "\n";
  '
)"

Would define a $php_varname shell variable for each $varname string PHP variable.

Beware that PHP variables that contain NUL bytes trip escapeshellargs().

Answer 3

A very simplified version would be something as follows:

2 lines in config.php:

cat config.php
$variable1 = 'foo with bar';
$variable1 = 'foo2 with bar2';

Set Bash $variable1 to last matching instance of $variable1 in config.php, just in case it has been reset. If you want to change it to the first match, simply change tail -1 to head -1 in the following code:

variable1="$(grep -oE '\$variable1 = .*;' config.php | tail -1 | sed 's/$variable1 = //g;s/;//g')"

Confirm Bash variable via echo:

echo "$variable1"
'foo2 with bar2'

Note that this will mostly work for strings. There are many types of PHP variables that cannot be directly converted to Bash variables. The code above will grab the last $variable1 referenced in config.php. Like I said, if that variable has been set multiple times, you can set to the first value or last value by toggling head or tail in the Bash command that sets the variable.