PHP Questions on Files

1) How to include remote file in PHP?
To allow inclusion of remote files, the directive allow_url_include must be set to On in php.ini

But it is bad, in a security-oriented point of view ; and, so, it is generally disabled (I’ve never seen it enabled, actually)

It is not the same as allow_url_fopen, which deals with opening (and not including) remote files — and this one is generally enabled, because it makes fetching of data through HTTP much easier (easier than using curl)

$url = “http://www.example.org/”;
$ch = curl_init();
curl_setopt ($ch, CURLOPT_URL, $url);
curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT, 5);
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, true);
$contents = curl_exec($ch);

As long as allow_url_fopen is enabled in php.ini, you can use HTTP and FTP URLs with most of the functions that take a filename as a parameter. In addition, URLs can be used with the include, include_once, require and require_once statements (since PHP 5.2.0, allow_url_include must be enabled for these)

2) What are the different ways of reading a file?

a) file — Reads entire file into an array
$lines = file('http://www.example.com/'); // $lines is an array

b) file_get_contents – Reads entire file into a string
$file = file_get_contents('./people.txt', true); // $file is a string

c) fread – Binary-safe file read
fread() reads up to length bytes from the file pointer referenced by handle. It stops if it encounters EOF earlier.

$filename = "/usr/local/something.txt";
$handle = fopen($filename, "r");
$contents = fread($handle, filesize($filename)); // $contents is a string
fclose($handle);

d) fgets – Gets line from file pointer
$handle = @fopen("/tmp/inputfile.txt", "r");
if ($handle) {
while (($buffer = fgets($handle, 4096)) !== false) {
echo $buffer;
}
if (!feof($handle)) {
echo "Error: unexpected fgets() fail\n";
}
fclose($handle);
}

e) fscanf
fscanf() is similar to sscanf(), but it takes its input from a file associated with handle and interprets the input according to the specified format, which is described in the documentation for sprintf(). Each call to fscanf() reads one line from the file

$handle = fopen("users.txt", "r");
while ($userinfo = fscanf($handle, "%s\t%s\t%s\n")) {
list ($name, $profession, $countrycode) = $userinfo;
//... do something with the values
}
fclose($handle);

f) fgetc — Gets character from file pointer
$fp = fopen('somefile.txt', 'r');
if (!$fp) {
echo 'Could not open file somefile.txt';
}
while (false !== ($char = fgetc($fp))) {
echo "$char\n";
}

2) How to delete a file ?
unlink();