suid(glossar.html) - phpMan

getresuid (2)        - get real, effective and saved user/group IDs
getresuid32 (2)      - get real, effective and saved user/group IDs
setfsuid (2)         - set user identity used for file system checks
setfsuid32 (2)       - set user identity used for file system checks
setresuid (2)        - set real, effective and saved user or group ID
setresuid32 (2)      - set real, effective and saved user or group ID