setuid、setgid等 Functions

setuid、setgid - set user identity

作用

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

int setuid(uid_t uid);
int setgid(gid_t gid);
//Return： 0 if OK， -1 on error

具体能改变哪些ID取决于下图

seteuid、setegid

effective user ID and group ID

seteuid, setegid - set effective user or group ID

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

int seteuid(uid_t euid);
int setegid(gid_t egid);
//Both return: 0 if OK, -1 on error

Group IDs