Replace key of a PHP array by the value of a constant with common name?

Question

The title may be sound confusing so here is the code to explain clearly.

I wrote the following code in a PHP script

    $options=array(
        CURLOPT_URL => 'http://site2sms.com/userregistration_next.asp',
        CURLOPT_REFERER => 'http://site2sms.com/UserRegistration_Next.asp',
        CURLOPT_USERAGENT => 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31',
        CURLOPT_POST => TRUE,
        CURLOPT_POSTFIELDS => http_build_query($post_fields)
    );

But, when the dump the array using var_dump function here is what I got

array (size=5)
  10002 => string 'http://site2sms.com/userregistration_next.asp' (length=45)
  10016 => string 'http://site2sms.com/UserRegistration_Next.asp' (length=45)
  10018 => string 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31' (length=108)
  47 => int 1
  10015 => string 'action=UserCreate&txtFullName=fdsf&genderCombo=Male&birth_day=2&birth_month=12&birth_year=2013&txtEmail=fdsf%40dssad&ProfessCombo=1&StateCombo=Delhi&txtMobileNum=4234&cityCombo=223&Submit=Register' (length=196)

Clearly, the value of constant CURLOPT_URL is replaced by 10002 in its dump. So, I replaced the original array by this

    $options=array(
        'CURLOPT_URL' => 'http://site2sms.com/userregistration_next.asp',
        'CURLOPT_REFERER' => 'http://site2sms.com/UserRegistration_Next.asp',
        'CURLOPT_USERAGENT' => 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31',
        'CURLOPT_POST' => TRUE,
        'CURLOPT_POSTFIELDS' => http_build_query($post_fields)
    );

to get this dump value

array (size=5)
  'CURLOPT_URL' => string 'http://site2sms.com/userregistration_next.asp' (length=45)
  'CURLOPT_REFERER' => string 'http://site2sms.com/UserRegistration_Next.asp' (length=45)


  'CURLOPT_USERAGENT' => string 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31' (length=108)
  'CURLOPT_POST' => boolean true
  'CURLOPT_POSTFIELDS' => string 'action=UserCreate&txtFullName=fdsf&genderCombo=Male&birth_day=2&birth_month=12&birth_year=2013&txtEmail=fdsf%40dssad&ProfessCombo=1&StateCombo=Delhi&txtMobileNum=4234&cityCombo=485&Submit=Register' (length=196)

Now, I am getting an error Warning: curl_setopt_array(): Array keys must be CURLOPT constants or equivalent integer values. So, How can I tweak the array so that dumping array shows constant name not value and when used with curl_setopt_array it should work nicely. I am looking for some function that can be used a step earlier than curl_setopt_array function so that it can make necessary changes to array. If it is not possible through PHP built in functions please suggest me how to create this function manually.

Note: I have raised this question out of curiosity. I am learning PHP these days — user2286243
– user2286243, Commented Dec 18, 2013 at 23:57
You could keep your string keys, but utilize constant() for passing its keys to _setopt. — mario
– mario, Commented Dec 18, 2013 at 23:59
@mario How can I implement this in my array? Is there some built in functions for it or I should for each loop for it. — user2286243
– user2286243, Commented Dec 19, 2013 at 0:02

mario · Accepted Answer · 2013-12-19 01:02:07Z

2

There's even a compact way for that:

curl_setopt_array($ch,
    array_combine(
        array_map("constant", array_keys($options)),
        array_values($options)
    )
);

To explain this a little:

constant() converts a stringy constant name to its value
array_keys() just extracts the keys from your $options array
array_map() applys constant to each key, returning its value, but keeps the order of the now integer-key list
array_values() returns the indexed list of your $options values
finally array_combine() remerges the both-still-in-order numeric keys with their values

Since you mostly need this for commanding curl, I'd also like to present a little alternative here. Not for the overall question, but the concrete task at hand.

I'm personally using a small hybrid/fluent wrapper curl.php for such things. It's possibly often shorter than the array options approach:

$result =
    curl()
       ->URL('http://site2sms.com/userregistration_next.asp')
       ->REFERER('http://site2sms.com/UserRegistration_Next.asp')
       ->USERAGENT('Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/')
       ->POST(true)
       ->POSTFIELDS(http_build_query($post_fields))
       ->exec();

Which reduces all the curl_ function and CURL_ constant prefixes.
(But it still had ->setopt_array() available, btw.)

edited Dec 19, 2013 at 1:02

answered Dec 19, 2013 at 0:06

mario

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9 Comments

Eugen Rieck Over a year ago

This is an accident waiting to happen! If used inside a class, it will prefer a method named "constant" to the global function.

mario Over a year ago

@EugenRieck I'm not sure I've ever seen array_map call up a method without passing [$this,'method'].

Eugen Rieck Over a year ago

Just try it out, inside a class, where a method has the same name as a global function. Verified on PHP 5.3.10-1ubuntu3.9 with Suhosin-Patch right now. (I was bitten by this in the past ...)

mario Over a year ago

@EugenRieck Seriously, you have to show me. Can't reproduce it with either 5.3.10-1ubuntu3.8+suhosin, 5.4.8, 5.5.5, 5.2.2, 5.1.0, 5.0.5 or 4.4.7.

Eugen Rieck Over a year ago

Don't know how this will format: <?php define('FOO_CONST','BAR-NAME'); class foo { function constant($name) {return "foo-name";} function test() {return constant('FOO_CONST');} } echo foo::test(); ?> outputs 'foo-name'

|

phil-lavin · Accepted Answer · 2013-12-19 00:23:05Z

Here's an example dump function for this. Pass it the array and a prefix of the constants it'll use for the map.

<?php

function const_keyed_array_dump($arr, $const_prefix) {
        static $map = array();

        // Primative caching
        if (!$map) {
                foreach (get_defined_constants() as $name=>$val) {
                        if (strpos($name, $const_prefix) === 0) {
                                $map[$val] = $name;
                        }
                }
        }

        $output = array();

        foreach ($arr as $key=>$val) {
                $output[$map[$key]] = $val;
        }

        return $output;
}

var_dump(
        const_keyed_array_dump(
                array(
                        CURLOPT_DNS_USE_GLOBAL_CACHE => 'foo',
                        CURLFTPSSL_TRY => 'bar',
                ),
                'CURL'
        )
);

Eugen Rieck · Accepted Answer · 2013-12-19 00:03:22Z

-1

CURLOPT_URL (without quotes) is just another name for the integer 10002 - the moment you use it, it is translated. This is a one-way process!

If you want to use the string representation, you need either interims table:

$dumpableoptions=array(
    'CURLOPT_URL' => 'http://site2sms.com/userregistration_next.asp',
    ...
);

$translations=array(
    'CURLOPT_URL' => CURLOPT_URL,
    ...
);

and later

$options=array();
foreach ($dumpableoptions as $key=>$value)
  $options[$translations[$key]]=$value;

or you have to make use of the horror of horrors: eval(). I am not willing to provide code for that.

EDIT

After reading @mario's comment, I found out, that after developing in PHP since version 2 I still have lots to learn! I simply didn't know the constant() function. This changes a lot:

forget the interims table, it is inside the cURL extension
change the later code to

.

$options=array();
foreach ($dumpableoptions as $key=>$value)
  $options[constant($key)]=$value;

answered Dec 19, 2013 at 0:03

Eugen Rieck

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2 Comments

user2286243 Over a year ago

@mario again got another advanced way for that.

Eugen Rieck Over a year ago

@VarunAgw And as I commented there, it has a big disadvantage!

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