seteuid(3C)

NAME
     seteuid, setruid, setegid, setrgid - set user and group IDs

SYNOPSIS
     #include <unistd.h>

     int seteuid(uid_t euid);
     int setruid(uid_t ruid);

     int setegid(gid_t egid);
     int setrgid(gid_t rgid);

DESCRIPTION
     seteuid (setegid) sets the effective user ID (group ID) of the current
     process.

     setruid (setrgid) sets the real user ID (group ID) of the current
     process.

     These calls are only permitted to the super-user or if the argument is
     the real or effective ID.

DIAGNOSTICS
     Zero is returned if the user (group) ID is set.  Otherwise -1 is returned
     and errno is set to EPERM if the caller is not the super-user and a
     disallowed ID is used.

SEE ALSO
     setreuid(2), setregid(2), setuid(2), setgid(2), getuid(2), getgid(2).