In many UnixUnix (officially trademarked as UNIX®) is a computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and Douglas McIlroy. Today's Unix systems are split into various branches, developed over time by AT&T as well as various commercial ...Unix variants, "nobody" is the conventional name of a user accountUser in a computing context refers to one who uses a computer system. Users may need to identify themselves for the purposes of accounting, security, logging and resource management. In order to identify oneself, a user has an account (a user account) and a username (also called a screen name, handle, nickname, or nick on some systems), and in most cases also a password (see below). Users employ the user interface to access systems, and the ...user account which owns no files, is in no privileged groups, and has no abilities over and above those which every user has.
It is common to run daemonsIn Unix and other computer multitasking operating systems, a daemon (IPA pronunciation: or ) is a computer program that runs in the background, rather than under the direct control of a user; they are usually initiated as processes. Typically daemons have names that end with the letter "d" (for example, syslogd, the daemon that handles the system log, or sshd, which handles the incoming SSH connections). In ...daemons as nobody, especially serversServer has several related meanings. In information technology, a server (also called a server application) is "an application program that accepts connections in order to service requests by sending back responses." (RFC 2616 (Hypertext Transfer Protocol ...servers, in order to limit the damage that could be done by a malicious user who gained control of it. However, the usefulness of this technique is reduced if more than one daemon is run like this, because then gaining control of one daemon would provide control of them all. The reason is that nobody processes have the ability to send signals to each other and even (on LinuxLinux (IPA pronunciation: ) is a Unix-like computer operating system. Linux is one of the most prominent examples of free software and open source development; its underlying source code can be freely modified, used, and redistributed by anyone. The Linux kernel was first released to the public on 17 September 1991, for the Intel x86 PC architecture. The kernel was augmented with system utilities and libraries from the GNU project to create a usable operating system, which later led to the alternate term GNU/Linux. Linux is now packaged ...Linux) ptracestrace is a debugging utility in Linux to monitor the system calls used by a program and all the signals it receives, similar to "truss" utility in other Unix systems. This is made possible by a Linux kernel feature known as ptrace. A similar utility is provided by Cygwin.ptrace each other. Creating one account for each daemon provides for a tighter security policy, and is specified by the Linux Standard BaseThe Linux Standard Base, or LSB, is a joint project by several Linux distributions under the organizational structure of the Linux Foundation to standardize the internal structure of Linux-based operating systems. The LSB is based on the POSIX specification, the Single UNIX Specification, and several ...Linux Standard Base.
