setuid和seteuid函数有什么区别.在man page中,两个函数都有类似的描述.
setuid的：
DESCRIPTION
setuid() sets the effective user ID of the calling process. If the effective UID of the caller is root,the real UID and saved
set-user-ID are also set.
个seteuid：
DESCRIPTION
seteuid() sets the effective user ID of the calling process. Unprivileged user processes may only set the effective user ID to
the real user ID,the effective user ID or the saved set-user-ID.
在两个描述中都包含设置调用进程的有效用户ID.那么有什么区别呢
这两个以及这些功能之间的功能如何不同.
还有一个疑问是,只使用chmod(chmod u s)
可以为文件设置set user id权限.然后,仅在程序的运行时期间,该进程具有设置为设置的权限
用户身份.除了这些函数之外,这些函数如何将有效的用户标识设置为进程.
最佳答案
从man page：
Thus,a set-user-ID-root program wishing to temporarily drop root
privileges,assume the identity of an unprivileged user,and then
regain root privileges afterward cannot use setuid(). You can
accomplish this with seteuid(2).
