dynamically put together a variable from other variables in php

Question

I was wondering if you can construct a PHP variable from another variable.

I want to build a dynamic variable based on the output of another variable.

$cf = new RecursiveDirectoryIterator(dirname(__DIR__) . DS . "configuration");

foreach (new RecursiveIteratorIterator($cf) as $filename => $file) {
    if ($cf->getFilename() != "." && $cf->getFilename() != "..") {
        $ex = explode(".", $filename);
        $_.$ex[0] = parse_ini_file($filename, true);
    }
}

in that code above I want to look through my configuration folder and making ouputing something like this.

Lets say we have db.ini, and theme.ini in the configuration folder

so the output would hopefully look like

$_db = parse_ini_file("db.ini", true);
$_theme = parse_ini_file("theme.ini", true);

I thought maybe concatenating variables together I could make a new variable ;-)

The scenario is that I want to dump as many .ini files into my configuration folder and have my script dynamically make the $_ variables for me with the parse_ini_file function loaded for that file.

or am I just nuts?

It's not immediately clear what you're trying to accomplish. Please reword your question. — cdhowie
– cdhowie, Commented Aug 23, 2011 at 4:24

Jason · Accepted Answer · 2011-08-23 04:33:14Z

2

Dynamic Variables

What you want to do is possible, they are better known as variable variables:

http://php.net/manual/en/language.variables.variable.php

For example

$sql = "my query";
$variable = "sql";
echo ${$variable};

Output

my query

So for your example, just change it to

$_{$ex[0]} = parse_ini_file($filename, true);

A better Way

The inherent problem with that though is that it's going to be much harder to keep track of your ini files and what variable they are stored in. A much cleaner method is to use associative arrays.

http://au.php.net/manual/en/function.array.php

So your code would look like this:

$name = pathinfo($filename, PATHINFO_FILENAME); //mildly more accurate then explode
$ini[$name] = parse_ini_file($filename, true);

then after your look just print_r $ini to see the results

print_r($ini);

answered Aug 23, 2011 at 4:33

Jason

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Daniel · Accepted Answer · 2011-08-23 04:32:51Z

0

Try

$name = '_' . $ex[0];
$$name = parse_ini_file($filename, true);

answered Aug 23, 2011 at 4:32

Daniel

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cdhowie · Accepted Answer · 2011-08-23 04:34:00Z

0

You could do this:

// Inside the loop.
$ex = explode(".", $filename);
$variable = '_' . $ex[0];
$$variable = parse_ini_file($filename, true);

This would do what you want. However, be aware that if $ex[0] is something that's not a syntactically-valid PHP variable name (like "foo.bar") then the variable will be inaccessible except through the dynamic-variable mechanism ($varname = "foo.bar"; $value = $$varname;).

Also, make sure that you trust the INI file you're reading, since this has the potential to clobber your own variables and overwrite them with other data.

answered Aug 23, 2011 at 4:34

cdhowie

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2 Comments

Eli Over a year ago

well the variables are my own personal files, i trust myselt in that sense. So if i use $$varname bit you mentioned would be better?

cdhowie Over a year ago

The code at the top of my answer is the code you'd want to use.

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