The remote shell (rsh) is a

command line A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and pro ...

computer program A computer program is a sequence or set of instructions in a programming language for a computer to execute. Computer programs are one component of software, which also includes documentation and other intangible components. A computer progra ...

that can execute shell commands as another user, and on another computer across a

computer network A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections ar ...

. The remote system to which ''rsh'' connects runs the ''rsh''

daemon Daimon or Daemon (Ancient Greek: , "god", "godlike", "power", "fate") originally referred to a lesser deity or guiding spirit such as the daimons of ancient Greek religion and mythology and of later Hellenistic religion and philosophy. The wo ...

(rshd). The daemon typically uses the well-known

Transmission Control Protocol The Transmission Control Protocol (TCP) is one of the main protocols of the Internet protocol suite. It originated in the initial network implementation in which it complemented the Internet Protocol (IP). Therefore, the entire suite is common ...

(TCP)

port number In computer networking, a port is a number assigned to uniquely identify a connection endpoint and to direct data to a specific service. At the software level, within an operating system, a port is a logical construct that identifies a specific ...

514.

History

''Rsh'' originated as part of the

BSD Unix The Berkeley Software Distribution or Berkeley Standard Distribution (BSD) is a discontinued operating system based on Research Unix, developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berke ...

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ef ...

, along with rcp, as part of the

rlogin The Berkeley r-commands are a suite of computer programs designed to enable users of one Unix system to log in or issue commands to another Unix computer via TCP/IP computer network. The r-commands were developed in 1982 by the Computer System ...

package on 4.2BSD in 1983. rsh has since been ported to other operating systems. The rsh command has the same name as another common UNIX utility, the restricted shell, which first appeared in

PWB/UNIX The Programmer's Workbench (PWB/UNIX) is an early, now discontinued, version of the Unix operating system that had been created in the Bell Labs Computer Science Research Group of AT&T. Its stated goal was to provide a time-sharing working envir ...

; in

System V Release 4 Unix System V (pronounced: "System Five") is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, an ...

, the restricted shell is often located at /usr/bin/rsh.

Limitations

As described in the

article, the rsh

protocol Protocol may refer to: Sociology and politics * Protocol (politics), a formal agreement between nation states * Protocol (diplomacy), the etiquette of diplomacy and affairs of state * Etiquette, a code of personal behavior Science and technology ...

is not secure for network use, because it sends unencrypted information over the network, among other reasons. Some implementations also

authenticate Authentication (from ''authentikos'', "real, genuine", from αὐθέντης ''authentes'', "author") is the act of proving an assertion, such as the identity of a computer system user. In contrast with identification, the act of indicati ...

by sending unencrypted

password A password, sometimes called a passcode (for example in Apple devices), is secret data, typically a string of characters, usually used to confirm a user's identity. Traditionally, passwords were expected to be memorized, but the large number of ...

s over the network. rsh has largely been replaced with the

secure shell The Secure Shell Protocol (SSH) is a cryptographic network protocol for operating network services securely over an unsecured network. Its most notable applications are remote login and command-line execution. SSH applications are based ...

(ssh) program, even on local networks.

Example

As an example of rsh use, the following executes the command ''mkdir testdir'' as user ''remoteuser'' on the computer ''host.example.com'' running a UNIX-like system: $ rsh -l remoteuser host.example.com "mkdir testdir" After the command has finished rsh terminates. If no command is specified then rsh will log in on the remote system using

. The network location of the remote computer is looked up using the

Domain Name System The Domain Name System (DNS) is a hierarchical and distributed naming system for computers, services, and other resources in the Internet or other Internet Protocol (IP) networks. It associates various information with domain names assigned ...

References

rsh - remote shell
- rsh

man page A man page (short for manual page) is a form of software documentation usually found on a Unix or Unix-like operating system. Topics covered include computer programs (including library and system calls), formal standards and conventions, and ev ...

. *{{man, 1, rsh, Darwin, remote shell Internet protocols OS/2 commands Unix network-related software

History

Limitations

Example

See also

References