PHPsys_get_temp_dir()The function returns the path to the system temporary folder, usually on Unix/Linux systems/tmp, on Windows systems it is%TEMP%或%TMP%。
When you create a temporary file, it is usually saved in the system temporary folder. System temporary folders are usually managed by the operating system or web server, so in some cases, the system periodically clears old files in these folders to ensure that they do not take up too much disk space.
However, please note that the cleaning mechanism for temporary folders varies between operating systems and web servers. In some cases, temporary files may persist until you delete them manually. In other cases, temporary files may be automatically cleared after a short period of time, such as when your script completes execution and closes.
Therefore, if you need to ensure that your temporary files are deleted promptly, it is best to delete them manually after using them, for example, using PHPunlink()function. At the same time, make sure you only use temporary files when necessary and always consider security issues.
