2010/11 : [1]Building Web Applications using MySQL and PHP (W1)Slide Topic Files

2010/11 : [2]Building Web Applications using MySQL and PHP (W1)Slide Topic A file is opened with fopen() as a “stream”, and PHP returns a ‘handle’ to the file that can be used to reference the open file in other functions. Each file is opened in a particular mode. A file is closed with fclose() or when your script ends. Use full path to file Path to currently running script: dirname($_SERVER['SCRIPT_FILENAME']) Open/Close a File

2010/11 : [3]Building Web Applications using MySQL and PHP (W1)Slide Topic File Open Modes ‘r’ Open for reading only. Start at beginning of file. ‘r+’ Open for reading and writing. Start at beginning of file. ‘w’ Open for writing only. Remove all previous content, if file doesn’t exist, create it. ‘a’ Open writing, but start at END of current content. ‘a+’ Open for reading and writing, start at END and create file if necessary.

2010/11 : [4]Building Web Applications using MySQL and PHP (W1)Slide Topic File Open/Close Example <?php // open file to read $toread = fopen(‘some/file.ext’,’r’); // open (possibly new) file to write $towrite = fopen(‘some/file.ext’,’w’); // close both files fclose($toread); fclose($towrite); ?>

2010/11 : [5]Building Web Applications using MySQL and PHP (W1)Slide Topic Now what..? If you open a file to read, you can use more in-built PHP functions to read data.. If you open the file to write, you can use more in-built PHP functions to write..

2010/11 : [6]Building Web Applications using MySQL and PHP (W1)Slide Topic Reading Data There are two main functions to read data: fgets($handle,$bytes) Reads up to $bytes of data, stops at newline or end of file (EOF) fread($handle,$bytes) Reads up to $bytes of data, stops at EOF.

2010/11 : [7]Building Web Applications using MySQL and PHP (W1)Slide Topic Reading Data We need to be aware of the End Of File (EOF) point.. feof($handle) Whether the file has reached the EOF point. Returns true if have reached EOF.

2010/11 : [8]Building Web Applications using MySQL and PHP (W1)Slide Topic Data Reading Example $handle = fopen('people.txt', 'r'); while (!feof($handle)) { echo fgets($handle, 1024); echo ' '; } fclose($handle);

2010/11 : [9]Building Web Applications using MySQL and PHP (W1)Slide Topic Data Reading Example $handle = fopen('people.txt', 'r'); while (!feof($handle)) { echo fgets($handle, 1024); echo ' '; } fclose($handle); Open the file and assign the resource to $handle $handle = fopen('people.txt', 'r');

2010/11 : [10]Building Web Applications using MySQL and PHP (W1)Slide Topic Data Reading Example $handle = fopen('people.txt', 'r'); while (!feof($handle)) { echo fgets($handle, 1024); echo ' '; } fclose($handle); While NOT at the end of the file, pointed to by $handle, get and echo the data line by line while (!feof($handle)) { echo fgets($handle, 1024); echo ' '; }

2010/11 : [11]Building Web Applications using MySQL and PHP (W1)Slide Topic Data Reading Example $handle = fopen('people.txt', 'r'); while (!feof($handle)) { echo fgets($handle, 1024); echo ' '; } fclose($handle); Close the file fclose($handle);

2010/11 : [12]Building Web Applications using MySQL and PHP (W1)Slide Topic File Open shortcuts.. There are two ‘shortcut’ functions that don’t require a file to be opened: $lines = file($filename) Reads entire file into an array with each line a separate entry in the array. $str = file_get_contents($filename) Reads entire file into a single string.

2010/11 : [13]Building Web Applications using MySQL and PHP (W1)Slide Topic Writing Data To write data to a file use: fwrite($handle,$data) Write $data to the file. There is write shortcut function.. file_put_contents($filename, $data);

2010/11 : [14]Building Web Applications using MySQL and PHP (W1)Slide Topic Data Writing Example $handle = fopen('people.txt', 'a'); fwrite($handle, “\nFred:Male”); fclose($handle);

2010/11 : [15]Building Web Applications using MySQL and PHP (W1)Slide Topic Data Writing Example $handle = fopen('people.txt', 'a'); fwrite($handle, '\nFred:Male'); fclose($handle); $handle = fopen('people.txt', 'a'); Open file to append data (mode 'a') fwrite($handle, '\nFred:Male'); Write new data (with line break after previous data)

2010/11 : [16]Building Web Applications using MySQL and PHP (W1)Slide Topic Other File Operations Delete file unlink('filename'); Rename (file or directory) rename('old name', 'new name'); Copy file copy('source', 'destination'); And many, many more!

2010/11 : [17]Building Web Applications using MySQL and PHP (W1)Slide Topic Permissions On Linux/Unix/Windows access to each file is governed by it's permissions The web process (apache) runs as a particular “user” e.g. www-data, apache, nobody etc. Have to be careful when mixing ftp-ed and uploaded files with permissions.

2010/11 : [18]Building Web Applications using MySQL and PHP (W1)Slide Topic Detailed discussion of permissions is beyond the scope of this course. Setting Permissions. e.g. Files Use FTP software to set file permissions to 666 Use chmod('filename', 0666) Created Directories Use FTP software to set file permissions to 777 Use chmod('directory', 0777) Permissions

2010/11 : [19]Building Web Applications using MySQL and PHP (W1)Slide Topic PHP Safe Mode is an attempt to solve the shared-server security problem. Many ISP's use safe mode for now. It has been DEPRECATED as of PHP Security and safe mode

2010/11 : [20]Building Web Applications using MySQL and PHP (W1)Slide Topic Because of the safe mode restrictions, it is not possible to create a folder and then store files in it. One workaround is to create the folder first, using the FTP software, set the permissions to 7 for everyone (757) This will allow the script to store files in the folder Safe mode work around for dcs

2010/11 : [21]Building Web Applications using MySQL and PHP (W1)Slide Topic In other servers it is safer to change the group of the folder that you have created manually, so that it is the group of the web server (e.g. nogroup, dba, etc) Then set the permissions for the group to be 7 (775) This will allow PHP on the server to create/change files and folders, but not other users of the server. Safe mode work around (2)

2010/11 : [22]Building Web Applications using MySQL and PHP (W1)Slide Topic Dealing With Directories Open a directory $handle = opendir('dirname'); $handle 'points' to the directory Read contents of directory readdir($handle) Returns name of next file in directory Files are sorted as on filesystem Close a directory closedir($handle) Closes directory 'stream'

2010/11 : [23]Building Web Applications using MySQL and PHP (W1)Slide Topic Directory Example //In filesystems. means current directory $handle = opendir('./'); while(false !== ($file=readdir($handle))) { echo "$file "; } closedir($handle);

2010/11 : [24]Building Web Applications using MySQL and PHP (W1)Slide Topic Directory Example $handle = opendir('./'); while(false !== ($file=readdir($handle))) { echo "$file "; } closedir($handle); Open current directory $handle = opendir('./');

2010/11 : [25]Building Web Applications using MySQL and PHP (W1)Slide Topic Directory Example $handle = opendir('./'); while(false !== ($file=readdir($handle))) { echo "$file "; } closedir($handle); Whilst readdir() returns a name, loop through directory contents, echoing results while(false !== ($file=readdir($handle))) { echo "$file "; }

2010/11 : [26]Building Web Applications using MySQL and PHP (W1)Slide Topic Directory Example $handle = opendir('./'); while(false !== ($file=readdir($handle))) { echo "$file "; } closedir($handle); Close the directory stream closedir($handle);

2010/11 : [27]Building Web Applications using MySQL and PHP (W1)Slide Topic Other Directory Operations Get current directory getcwd() Change Directory chdir('dirname'); Create directory mkdir('dirname'); Delete directory (MUST be empty) rmdir('dirname'); And more!

2010/11 : [28]Building Web Applications using MySQL and PHP (W1)Slide Topic We know all this... so what's new?

2010/11 : [29]Building Web Applications using MySQL and PHP (W1)Slide Topic Send this file: Uploading files

2010/11 : [30]Building Web Applications using MySQL and PHP (W1)Slide Topic Uploading files Send this file: "multipart/form-data" Signifies that files can be uploaded by the form

2010/11 : [31]Building Web Applications using MySQL and PHP (W1)Slide Topic Send this file: Uploading files Sets the maximum size file that the form will accept. Checked by PHP... and perhaps a little useless!

2010/11 : [32]Building Web Applications using MySQL and PHP (W1)Slide Topic Send this file: Uploading files Creates an input box with a browse button for file selection. The 'name' will be used in the processing to get information about the file and deal with it accordingly.

2010/11 : [33]Building Web Applications using MySQL and PHP (W1)Slide Topic File information stored in global array $_FILES For the example ( name="userfile" ) $_FILES['userfile']['name'] Original name of the file $_FILES['userfile']['type'] The mime type of the file (if provided), e.g "image/gif". NOT checked on the PHP side. $_FILES['userfile']['size'] The size, in bytes, of the uploaded file. $_FILES['userfile']['tmp_name'] The temporary filename when initially stored on the server. $_FILES['userfile']['error'] The error code associated with this file upload The uploaded superglobal

2010/11 : [34]Building Web Applications using MySQL and PHP (W1)Slide Topic is_uploaded_file('filename'); Checks file was uploaded by a form Ensures script isn't tricked into working on a different file move_uploaded_file('filename','destination'); Moves temporary file to it's new home basename('path'); Returns just the filename from a path Uploaded file functions

2010/11 : [35]Building Web Applications using MySQL and PHP (W1)Slide Topic if (is_uploaded_file($_FILES['userfile']['tmp_name'])) { $updir = dirname(__FILE__).'/to/target/'; $upfilename = basename($_FILES['userfile']['name']); if ( move_uploaded_file($_FILES['userfile']['tmp_name'], $updir.$upfilename) ) { echo 'File successfully uploaded '; } else { echo 'File upload failed '; } Dealing with uploaded files

2010/11 : [36]Building Web Applications using MySQL and PHP (W1)Slide Topic if (is_uploaded_file($_FILES['userfile']['tmp_name'])) { $updir = dirname(__FILE__).'/to/target/'; $upfilename = basename($_FILES['userfile']['name']); if ( move_uploaded_file($_FILES['userfile']['tmp_name'], $updir.$upfilename) ) { echo 'File successfully uploaded '; } else { echo 'File upload failed '; } Dealing with uploaded files if (is_uploaded_file($_FILES['userfile']['tmp_name'])) Check that the files has been legitimately uploaded

2010/11 : [37]Building Web Applications using MySQL and PHP (W1)Slide Topic if (is_uploaded_file($_FILES['userfile']['tmp_name'])) { $updir = dirname(__FILE__).'/to/target/'; $upfilename = basename($_FILES['userfile']['name']); if ( move_uploaded_file($_FILES['userfile']['tmp_name'], $updir.$upfilename) ) { echo 'File successfully uploaded '; } else { echo 'File upload failed '; } Dealing with uploaded files $updir = dirname(__FILE__).'/to/target/'; $upfilename = basename($_FILES['userfile']['name']); Set the directory where the file will go. Then append the 'real' filename to the directory.

2010/11 : [38]Building Web Applications using MySQL and PHP (W1)Slide Topic if (is_uploaded_file($_FILES['userfile']['tmp_name'])) { $updir = dirname(__FILE__).'/to/target/'; $upfilename = basename($_FILES['userfile']['name']); if ( move_uploaded_file($_FILES['userfile']['tmp_name'], $updir.$upfilename) ) { echo 'File successfully uploaded '; } else { echo 'File upload failed '; } Dealing with uploaded files if ( move_uploaded_file($_FILES['userfile']['tmp_name'], $updir.$upfilename) ) Move the file to its new location and check if it has succeeded.

2010/11 : [39]Building Web Applications using MySQL and PHP (W1)Slide Topic Useful Error Codes 0: UPLOAD_ERR_OK No error, file uploaded successfully. 1: UPLOAD_ERR_INI_SIZE The uploaded file exceed the upload_max_filesize directive in php.ini. 2: UPLOAD_ERR_FORM_SIZE The uploaded file exceeds the MAX_FILE_SIZE directive that was specified in the HTML form. 3: UPLOAD_ERR_PARTIAL The uploaded file was only partially uploaded. 4: UPLOAD_ERR_NO_FILE No file was uploaded. Upload error codes

2010/11 : [40]Building Web Applications using MySQL and PHP (W1)Slide Topic Can use error logic to check what you do Check the error code If OK (i.e. 0) Complete upload processing If not OK (i.e. any of the other numbers!) Stop processing and inform user of error Can also check type of upload e.g. $_FILES['userfile']['type'] Some image types image/gif, image/jpeg, image/png Errors

2010/11 : [41]Building Web Applications using MySQL and PHP (W1)Slide Topic Send these files: Uploading multiple files

2010/11 : [42]Building Web Applications using MySQL and PHP (W1)Slide Topic Send these files: Uploading multiple files Filename is set as an array to enable the data for more than one file to be stored.

2010/11 : [43]Building Web Applications using MySQL and PHP (W1)Slide Topic $updir = 'some/dir/'; foreach ($_FILES['userfile']['error'] as $key => $error) { if ($error == 0) { $tmp_name = $_FILES['userfile']['tmp_name'][$key]; $name=$_FILES['userfile']['name'][$key]; move_uploaded_file($tmp_name, "$updir$name"); } Processing multiple uploads

2010/11 : [44]Building Web Applications using MySQL and PHP (W1)Slide Topic $updir = 'some/dir/'; foreach ($_FILES['userfile']['error'] as $key => $error) { if ($error == 0) { $tmp_name = $_FILES['userfile']['tmp_name'][$key]; $name=$_FILES['userfile']['name'][$key]; move_uploaded_file($tmp_name, "$updir$name"); } Processing multiple uploads foreach ($_FILES['userfile']['error'] as $key => $error) For each file in the array assign the key to $key and the Error Code to $error

2010/11 : [45]Building Web Applications using MySQL and PHP (W1)Slide Topic $updir = 'some/dir/'; foreach ($_FILES['userfile']['error'] as $key => $error) { if ($error == 0) { $tmp_name = $_FILES['userfile']['tmp_name'][$key]; $name=$_FILES['userfile']['name'][$key]; move_uploaded_file($tmp_name, "$updir$name"); } Processing multiple uploads if ($error == 0) If the error code is 0 (No error) for the current file in the array we'll carry on processing.

2010/11 : [46]Building Web Applications using MySQL and PHP (W1)Slide Topic $updir = 'some/dir/'; foreach ($_FILES['userfile']['error'] as $key => $error) { if ($error == 0) { $tmp_name = $_FILES['userfile']['tmp_name'][$key]; $name=$_FILES['userfile']['name'][$key]; move_uploaded_file($tmp_name, "$updir$name"); } Processing multiple uploads $tmp_name = $_FILES['userfile']['tmp_name'][$key]; $name=$_FILES['userfile']['name'][$key]; move_uploaded_file($tmp_name, "$updir$name"); Get the temporary file name and the original name and then move the file to a previously set location

2010/11 : [47]Building Web Applications using MySQL and PHP (W1)Slide Topic HOE: File Uploads