actual User id:Some articles refer to it as the real user ID, which is the ID when we log on to the UNIX system.
Valid User ID: Defines the rights of the operator. A valid user ID is a property of a process that determines the access to the file
Actual User ID, valid user ID, and save setting user IDrealuserID: the actual user ID, which refers to the worker tiveuserid of the process executor: valid user ID, savedset-user-ID: save the set user ID as the inclutiveuser... actual user ID, valid
Actual user ID, valid user ID, and save Set user ID real user ID: the actual user ID, which is the valid user ID of the process executor, saved set-user-ID: Save the set user ID as a copy of the valid user ID, you can restore the original effectiv
Several Common Unix concepts are explained below.
First, we need to clarify that these concepts are related to processes.Real user ID indicates who actually executes the process. valid userid is mainly used to verify the File Access Permissions
In the UNIX system, privileges, such as being able to change the system's notion of the current date, and access control, such as being able to read or write a particle file, are based on user and group IDs. when our programs need additional
Real User id: Actual username, refers to who the process performer is
Effective User ID: Valid user ID, which is the access to the file when the process executes
Saved Set-user-id: Save the Set User ID as a copy of the effective user ID, which
UNIX environment Advanced Programming 8.11 mentioned in the user's actual ID, valid user ID, save the user ID set the concept of the time, I stuck, the internet to find a post, to do a detailed description. Collection of.
7.6 The USER ID of A
Every process has six or more IDs associated with it. These are shown in Figure 4.5.
Figure 4.5. user IDs and group IDs associated with each process
Real user IDReal group ID
Who we really are
Valid user IDValid
Recently, when I was watching apue, I saw 3.14 knots and fcntl.#include int fcntl (int fd, int cmd, .../* int arg */);Error returns-1, the specific return value depends on the cmd parameter.It refers to a cmd,fd_getfd fd_setfd returned by the file
For real-machine debugging, you must first register an app ID on the Apple website and buy an iPhone develop program (IDP) Developer license for $99. To create a CSR request for a certificate, follow these steps:
Set OCSP and CRL to disabled.
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.