How does URL Protocol determine if there is an installer locally?

how to determine whether to install the program locally, if so, pop up the corresponding program (to implement), if there is no installation prompt to install (not implemented)?

Mar.14,2021
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1ea8666-47c8b.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1ea8666-47c8b.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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