PHP file upload process and summary_PHP tutorial

Processing process of PHP file upload and all aspects involved

HTML Basics

Submit via POST form

PHP upload steps

1. The client submits the form via HTTP POST
2. After the file is uploaded, it is stored in the default temporary directory. Configure the php.ini attribute upload_tmp_dir and the PHP running environment variable TMPDIR to set the temporary directory. The function putenv setting in the PHP language is invalid
3. Use move_upload_file to move the upload from the temporary directory to the specified location (this step is not required if upload_tmp_dir has been set to the specified location)
4. If the form does not choose to upload files $_FILES['userfile']['type'] == "" , $_FILES['userfile']['size']== 0

PHP related global predefined variables

• $_POST [array] is used to obtain the parameters submitted by form POST
• $_FILES [array]
  • $_FILES['userfile']['name'] Original name of client machine userfile == name attribute in input control
  • $_FILES['userfile']['type'] File MIME type
  • $_FILES['userfile']['size'] Uploaded file size (bytes)
  • $_FILES['userfile']['tmp_name'] The temporary file name stored on the server after the file is uploaded
  • $_FILES['userfile']['error'] The error code related to the file upload

PHP related functions

• is_upload_file(string $filename) determines whether the file is uploaded through HTTP POST
• move_upload_file($file,$des) moves the uploaded file to a new location and checks that file is a legal uploaded file

The file names involved in the parameters are all absolute paths

php.ini related settings

• file_uploads [boolean] Whether to allow HTTP file upload
• upload_max_filesize [integer] Maximum size of uploaded files, default 2M
• post_max_size [integer]The maximum size allowed for POST data, this value>upload_max_filesize
• memory_limit [integer]this value>post_max_size
• max_input_time [integer] The upload time starts from when the script is executed and ends when all the data arrives at the server. The default is 60s
• upload_tmp_dir [string] Temporary directory for file upload and storage, writable by the PHP process owner user
• max_execution_time [integer] script execution time, system call, sleep, database query, file upload time does not include

Error message

• [0] UPLOAD_ERR_OK File uploaded successfully
• [1] UPLOAD_ERR_INI_SIZE File upload exceeds UPLOAD_MAX_SIZE
• [2] UPLOAD_ERR_FORM_SIZE The uploaded file size exceeds MAX_FILE_SIZE
• [3] UPLOAD_ERR_PARTIAL File partially uploaded successfully
• [4] UPLOAD_ERR_NO_FILE No file was uploaded
• [6] UPLOAD_ERR_NO_TMP_DIR Temporary folder not found
• [7] UPLOAD_ERR_CANT_WRITE File writing failed

PSP server upload security processing

• Suffix name check
• Size limit
• Content-Type check
• If it is a picture, use getimagesize to check the file type
• Set application directory and upload directory access permissions separately through the server

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http://www.bkjia.com/PHPjc/764195.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/764195.htmlTechArticleThe processing flow of PHP file upload and all aspects involved. Pay attention to HTML basics. Submit PHP upload steps via POST form. Customers The client submits the file through the HTTP POST form and then stores it...