NAME

setuid, setgid − set user and group IDs

SYNOPSIS

int setuid (uid)
int uid;

int setgid (gid)
int gid;

DESCRIPTION

Setuid is used to set the real user ID and effective user ID of the calling process. 

Setgid is used to set the real group ID and effective group ID of the calling process. 

If the effective user ID of the calling process is super-user, the real user (group) ID and effective user (group) ID are set to uid (gid).

If the effective user ID of the calling process is not super-user, but its real user (group) ID is equal to uid (gid), the effective user (group) ID is set to uid (gid).

Setuid will fail if the real user (group) ID of the calling process is not equal to uid (gid) and its effective user ID is not super-user.  ­[EPERM]

RETURN VALUE

Upon successful completion, a value of 0 is returned.  Otherwise, a value of −1 is returned and errno is set to indicate the error. 

SEE ALSO

getuid(2), intro(2). 

May 16, 1980