## Name seteuid, setegid - set effective user / group ID ## Synopsis ```**c++ #include int seteuid(uid_t); int setegid(gid_t); ``` ## Description Sets the effective user or group ID. For non-superusers, the effective ID can only be set to the current real or saved ID. In particular, `seteuid(geteuid())` will fail if the current effective user ID is not equal to the current real or saved ID. ## Return value If the call was set successful, returns 0. Otherwise, returns -1 and sets `errno` to describe the error. ## Errors * `EPERM`: The new ID is not equal to the real ID or saved ID, and the user is not superuser. ## See also * [`setuid_overview`(7)](../man7/setuid_overview.md) * [`geteuid`(2) / `getegid`(2)](geteuid.md) * [`getuid`(2) / `getgid`(2)](getuid.md) * [`getresuid`(2) / `getresgid`(2)](getresuid.md) * [`setuid`(2) / `setgid`(2)](setuid.md) * [`setresuid`(2) / `setresgid`(2)](setresuid.md)