Php processes and summarizes the file upload process. PHP file upload process and various related aspects note: HTML basic submission through POST form PHP Upload steps the client uses HTTPPOST form to submit a file after uploading the file to store the PHP file upload process and the procedures involved notes
HTML basics
Submit through POST form
PHP Upload steps
- The client submits the form through http post.
- After the file is uploaded, it is stored in the default temporary directory. you can configure the php. ini attributes upload_tmp_dir and the PHP runtime environment variable TMPDIR to set the temporary directory. the putenv setting function in php is invalid.
- 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)
- If the form does not select to upload FILES $ _ FILES ['userfile'] ['type'] = "", $ _ FILES ['userfile'] ['size'] = 0
Global predefined variables related to PHP
- $ _ POST [array] is used to obtain parameters submitted in form POST mode.
- $ _ FILES [array]
- $ _ FILES ['userfile'] ['name'] original name of the client machine userfile = name attribute in the input control
- $ _ FILES ['userfile'] ['type'] file MIME type
- $ _ FILES ['userfile'] ['size'] size of the uploaded file (in bytes)
- $ _ FILES ['userfile'] ['tmp _ name'] temporary file name stored on the server after the file is uploaded
- $ _ FILES ['userfile'] ['error'] error code related to the file Upload
PHP 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 whether the file is a valid file.
The file names involved in the parameters are all absolute paths.
Php. ini settings
- File_uploads [boolean] whether HTTP File upload is allowed
- Upload_max_filesize [integer] maximum size of the file to be uploaded. the default value is 2 MB.
- Post_max_size [integer] maximum size allowed by POST data. value> upload_max_filesize
- Memory_limit [integer] This value> post_max_size
- Max_input_time [integer] the upload time starts when the script is executed, and all data reaches the server end. the default value is 60 s.
- Upload_tmp_dir [string] temporary directory for file upload and storage. The PHP process owner can write permission.
- Max_execution_time [integer] script execution time, which is not included in system call, sleep, database query, and file upload time
Error message
- [0] UPLOAD_ERR_ OK file uploaded successfully
- [1] the upload of the UPLOAD_ERR_INI_SIZE file exceeds UPLOAD_MAX_SIZE.
- [2] UPLOAD_ERR_FORM_SIZE the size of the uploaded file exceeds MAX_FILE_SIZE
- [3] Part of UPLOAD_ERR_PARTIAL file uploaded successfully
- [4] no file is uploaded in UPLOAD_ERR_NO_FILE.
- [6] The temporary folder cannot be found in UPLOAD_ERR_NO_TMP_DIR.
- [7] An error occurred while writing the UPLOAD_ERR_CANT_WRITE file.
PHP server Upload security processing
- Suffix check
- Size limit
- Content-Type check
- If the image uses getimagesize for file type check
- Set the application directory and upload directory access permissions on the server.
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HTML basics submit PHP Upload steps through POST form the client submits files through the http post form Upload After storage...
