通过PHP的File函数库来完成上传图像文件并让其显示

通过File文件函数来操作上传的图片,下面是转自zend.com上的一篇文章，有许多可取之处，但是却感觉到众多的目录很古怪，大家看了后可以相互讨论一下：

// FILE 1: DISPLAY AND PROCESS ENTRY FORM AND UPLOAD PICTURE FILE TO SERVER

// full directory path
$filepath = "/home/httpd/html/tut/upload";

// 200K is the maximum (picture) file size to be accepted
define("MAX_FILE_SIZE", 200*1024);

function print_error ($err) {
echo "

$err

---

";
}

do {
// check if picture name variable has a value; if not, skip to the
// "while(false)" section of "do" statement
if(isset($picture)) {
// here is where the server transparently checks that the client picture file
// doesn't exceed maximum allowable size
if(getenv("CONTENT_LENGTH") > MAX_FILE_SIZE) {
print_error("File too large: $picture_name");
break;
}

// open client picture file for read only; "@" prefix tells fopen not to print
// message if there is an error, since function print_error does that

// if there is an error, break out of "do" loop and continue at "while(false)"

$fp = @fopen($picture,"r");
if(!$fp) {
print_error("Cannot open file: $picture_name");
break;
}

// generate unique name for session, use it to generate unique server
// directory name, and create the directory

srand((double) microtime() * 1000000);
$id = md5(uniqid(rand()));
$dirname = "$filepath/$id";
mkdir($dirname,0700);

// create the server picture file in the newly created server directory
$filename = $dirname . "/picture";

// open server picture file for write only; "@" prefix tells fopen not to
// print message if there is an error, since function print_error does that

// if there is an error, break out of "do" loop and continue at "while(false)"
$out = @fopen($filename,"w");
if(!$out) {
print_error("Cannot open file: $filename");
break;
}

// copy client picture file to server picture file
while($buffer = fread($fp,8192)) {
fwrite($out,$buffer);
}

// close client picture file and server picture file
fclose($fp);
fclose($out);

// create server name file in picture file directory; this file will hold the
// name of the picture file
$filename = $dirname . "/name";

// open server name file for write only; "@" prefix tells fopen not to print
// message if there is an error, since function print_error does that

// if there is an error, break out of "do" loop and continue at "while(false)"
$out = @fopen($filename,"w");
if(!$out) {
print_error("Cannot open file: $filename");
break;
}

// write the server picture name to the server name file, and close the server
// name file
fputs($out,$name);
fclose($out);

// display message that client picture file was successfully copied to the
// server, display a prompt to look at updated server photo gallery, and supply
// the HTML link

?>

Picture added. Thanks.

Continue to the gallery

// exit to the server photo gallery
exit();
}
} while(false);

// you get to here only when "if(isset($picture))" is false, which means that
// no picture name has been submitted, therefore go display the input form where
// the necessary information can be entered

?>

Photo gallery add

// start of segment of code for displaying input form

// using $PHP_SELF for value of "form action" causes form to refer to itself
// when "submit" button is clicked

?>

// pass the PHP constant MAX_FILE_SIZE to the HTML maximum file size
// constant MAX_FILE_SIZE

?>

// display the text boxes for entering user name and picture name, and store
// the entered values in PHP variables; browsing is enabled

?>

Your name is:

Your picture:

// display the "submit" button

?>

// ------------------------------------------------------
// FILE 2: DISPLAY THE SERVER PHOTO GALLERY

Photo gallery

// full directory path
$filepath = "/home/httpd/html/tut/upload";

// user's path in browser -- same as full directory path
$url_path = "/tut/upload";

// get unique server directory used for this user session
$dir = dir($filepath);

// loop through all server subdirectories for this user session
while($entry=$dir->read()) {
// if entry is system file (doesn't have picture files), go to next entry in
// "while" loop
if($entry == "." || $entry == "..") {
continue;
}

// open server name file for read only; "@" prefix tells fopen not to print
// message if there is an error, since function print_error does that

// if there is an error, go to next entry in "while" loop
$fp = @fopen("$filepath/$entry/name","r");
if(!$fp) {
print "Bad entry: $entry
";
continue;
}

// get name of the server picture file and close the server name file
$name = fgets($fp,4096);
fclose($fp);

// display each picture and its file name; in addition, "alt=" causes the file
// name to be displayed as ToolTip text when mouse points to picture

?>

"
alt="https://www.php1.cn/detail/"> https://www.php1.cn/detail/

}
?>