Implementation method of binary conversion of PHP images, _PHP tutorial

//Since the uploaded image is saved in a temporary file,
//We only need to read the file to get the passed image
$fp = fopen($_FILES["myFile"]["tmp_name"],"rb");
$buf = addslashes(fread($fp,$_FILES["myFile"]["size"]));
//Create a PDO object
$dbh = new PDO("mysql:host=localhost;port=
3306;dbname=test", "root", "123456″);
//Perform the insertion operation and save the result in a variable
$result = $dbh->query("INSERT INTO img (images) VALUES ('$buf')");
//Get the number of affected rows
if ($result->rowCount() >0) {
echo("Data has been inserted.");
} else {
echo("Cannot perform insertion operation.");
}
//Explicitly close the PDO connection
$dbh = NULL;
?>

$conn=@mysql_connect("localhost","root","123456″) or die("Server connection error!"); //Link database
@mysql_select_db("test",$conn) or die("No database found!");
$query="select * from img where Id=".$_GET['id'];
$result=mysql_query($query);
$num=mysql_num_rows($result);
$data = mysql_result($result,0,"images");
header("Content-type: image/" . $num['imgType']);
echo $data;
?>

"r+" opens the file in read-write mode, and the file pointer points to the beginning.

"w" opens the file for writing, points the file pointer to the beginning, and sets the length of the original file to 0. If the file does not exist, create a new file.

"w+" opens the file in read-write mode, points the file pointer to the beginning, and sets the length of the original file to 0. If the file does not exist, create a new file.

"a"The file opening mode is writing, and the file pointer points to the end of the file. If the file does not exist, create a new file.

"a+" The file opening mode is readable and writable, and the file pointer points to the end of the file. If the file does not exist, create a new file.

"b"If the text and binary files of the operating system are different, you can use this parameter. UNIX systems do not need to use this parameter.

2. Addslashes function

The Addslashes function is used to add slashes to a string. The syntax is as follows. Note: When I tested, I removed this function and it succeeded. You know the reason. You will understand if you try it yourself.

string addslashes(string str);

This function adds slashes to the quotation marks of the string that needs to be processed by the database so that the database query can operate smoothly. The characters that will be changed include single quotation marks (') and double quotation marks ( "), backslash() and null character NULL (the null byte).

3. fread function

The fread function is used to read a byte group of a specified length or to EOF at the end of the file. The syntax is as follows:

string fread(int fp, int length); safe for binary files

fread() reads up to length bytes from the file pointer file. This function reads up to length bytes, or when EOF is reached, or (for network streams) when a packet is available, or Reading of the file will stop when 8192 bytes have been read (after opening the userspace stream), whichever condition is encountered first.

Convert binary to image

Note: $newFilePath processes the generated image name and path. You can implement it yourself. The code is as follows:

You can save the read binary stream to the database, or you can directly write it into a picture to obtain the binary header file to know what type of file it belongs to. The code is as follows:

I hope this article will be helpful to everyone’s PHP programming design.