NAME

setuid — set-user-ID

SYNOPSIS

#include <sys/types.h>
#include <unistd.h>

int setuid(uid_t uid);

DESCRIPTION

If the process has appropriate privileges, setuid() sets the real user ID, effective user ID, and the saved set-user-ID to uid .

If the process does not have appropriate privileges, but uid is equal to the real user ID or the saved set-user-ID, setuid() sets the effective user ID to uid; the real user ID and saved set-user-ID remain unchanged.

RETURN VALUE

Upon successful completion, 0 is returned. Otherwise, -1 is returned and errno is set to indicate the error.

ERRORS

The setuid() function will fail and return -1 and set errno to the corresponding value if one or more of the following are true:

[EINVAL]

The value of the uid argument is invalid and not supported by the implementation.

[EPERM]

The process does not have appropriate privileges and uid does not match the real user ID or the saved set-user-ID.

EXAMPLES

None.

APPLICATION USAGE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

exec(3) , geteuid(3) , getuid(3) , setgid(3) , <sys/types.h> , <unistd.h> .

DERIVATION

Derived from Issue 1 of the SVID.