How would someone convert steamid64 (example: 76561198074259974) into a steamid (STEAM_0:0:56997123) using PHP/javascript (I would like to display a steamid on a loading screen, but not the steamid64)
Have a look at the code here for converting steamID to steamID64: https://forums.alliedmods.net/showthread.php?t=60899?t=60899
You can reverse it for converting steamID64 to steamID, for this the formula would be: (steamID64 - (76561197960265728 + (steamID64 % 2)))/2
This would give you the numbers after the second colon (:). If steamID64 is odd (steamID64 % 2) the number after the first colon would be 1 otherwise a 0.
来源：https://stackoverflow.com/questions/28516932/steam-convert-steamid64-to-steamid-using-php