NAME

setuid, setgid − set user and group IDs

SYNOPSIS

int setuid (uid)
int uid;

int setgid (gid)
int gid;

DESCRIPTION

setuid (setgid) is used to set the real user (group) ID and effective user (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).

If the effective user ID of the calling process is not super-user, but the saved set-user (group) ID from exec(2) is equal to uid (gid), the effective user (group) ID is set to uid (gid). 

setuid (setgid) fails if either of the following conditions is true:

­[EPERM] 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. 

­[EINVAL] The uid is out of range. 

SEE ALSO

getuid(2), intro(2). 

DIAGNOSTICS

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

September 02, 1992