Check to see if cURL is installed locally?

In the Terminal, type:

$ curl -V

That's a capital V for the version

If you are using XAMPP

In the current version (?) of the xampp you cannot locate the curl_exec in the php.ini, just try using

<?php
echo '<pre>';
var_dump(curl_version());
echo '</pre>';
?>

and save to your htdocs. Next go to your browser and paste

http://localhost/[your_filename].php

if the result looks like this

array(9) {
  ["version_number"]=>
  int(469760)
  ["age"]=>
  int(3)
  ["features"]=>
  int(266141)
  ["ssl_version_number"]=>
  int(0)
  ["version"]=>
  string(6) "7.43.0"
  ["host"]=>
  string(13) "i386-pc-win32"
  ["ssl_version"]=>
  string(14) "OpenSSL/1.0.2e"
  ["libz_version"]=>
  string(5) "1.2.8"
  ["protocols"]=>
  array(19) {
    [0]=>
    string(4) "dict"
    [1]=>
    string(4) "file"
    [2]=>
    string(3) "ftp"
    [3]=>
    string(4) "ftps"
    [4]=>
    string(6) "gopher"
    [5]=>
    string(4) "http"
    [6]=>
    string(5) "https"
    [7]=>
    string(4) "imap"
    [8]=>
    string(5) "imaps"
    [9]=>
    string(4) "ldap"
    [10]=>
    string(4) "pop3"
    [11]=>
    string(5) "pop3s"
    [12]=>
    string(4) "rtsp"
    [13]=>
    string(3) "scp"
    [14]=>
    string(4) "sftp"
    [15]=>
    string(4) "smtp"
    [16]=>
    string(5) "smtps"
    [17]=>
    string(6) "telnet"
    [18]=>
    string(4) "tftp"
  }
}

curl is enable

cURL is disabled for most hosting control panels for security reasons, but it's required for a lot of php applications. It's not unusual for a client to request it. Since the risk of enabling cURL is minimal, you are probably better off enabling it than losing a customer. It's simply a utility that helps php scripts fetch things using standard Internet URLs.

To enable cURL, you will remove curl_exec from the "disabled list" in the control panel php advanced settings. You will also find a disabled list in the various php.ini files; look in /etc/php.ini and other paths that might exist for your control panel. You will need to restart Apache to make the change take effect.

service httpd restart

To confirm whether cURL is enabled or disabled, create a file somewhere in your system and paste the following contents.

<?php
echo '<pre>';
var_dump(curl_version());
echo '</pre>';
?>

Save the file as testcurl.php and then run it as a php script.

php testcurl.php

If cURL is disabled you will see this error.

Fatal error: Call to undefined function curl_version() in testcurl.php on line 2

If cURL is enabled you will see a long list of attributes, like this.

array(9) {
["version_number"]=>
int(461570)
["age"]=>
int(1)
["features"]=>
int(540)
["ssl_version_number"]=>
int(9465919)
["version"]=>
string(6) "7.11.2"
["host"]=>
string(13) "i386-pc-win32"
["ssl_version"]=>
string(15) " OpenSSL/0.9.7c"
["libz_version"]=>
string(5) "1.1.4"
["protocols"]=>
array(9) {
[0]=>
string(3) "ftp"
[1]=>
string(6) "gopher"
[2]=>
string(6) "telnet"
[3]=>
string(4) "dict"
[4]=>
string(4) "ldap"
[5]=>
string(4) "http"
[6]=>
string(4) "file"
[7]=>
string(5) "https"
[8]=>
string(4) "ftps"
}
}