coshell ( 1 ) USER COMMANDScoshell ( 1 )

NAME

coshell - network shell coprocess server

SYNOPSIS

coshell [ options ] + | - | -command [ arg ... ]

DESCRIPTION

coshell is a local network shell coprocess server for programs using coshell(3). There is one coshell server per user. This server runs as a daemon on the user's home host, and only processes running on the home host have access to the server. The server controls a background ksh(1) shell process, initiated by rsh(1) or ssh(1), on each of the connected hosts. The environment of the local host shell is inherited from the server whereas the environment of remote shells is initialized by .profile and $ENV. The shells run with the ksh --bgnice and --monitor options.

Job requests are accepted from user processes on the local host and are executed on the connected hosts. stdout , stderr, FPATH, NPROC (see ENVIRONMENT), PWD, PATH, VPATH, vpath, umask and the environment variables listed in COEXPORT (see ENVIRONMENT) are set to match requesting user values. stdin is set to /dev/null; coshell does not directly support interactive jobs. Job scheduling is based on load and idle time information generated by the ss(1) system status daemon. This information is updated every 60 seconds on average.

The server is started by running coshell +. The command exits after a child server process is forked in the background. The optional info arguments name files containing local network host information which may be generated from two shell scripts genlocal and genshare under the subdirectory bin of the installation root directory. If no files are specified then the default local is used. The local network is comprised of hosts sharing the same file name space.

Attributes used by coshell can be categorized into two types, global and host-specific. The global attributes control coshell and are not associated with any particular host. Attribute value pairs, not including readonly ones, may be specified in the local network host information files, in COATTRIBUTES (see ENVIRONMENT) or may be set/added using coshell -a, and may be referenced in an expression in COATTRIBUTES. Attribute names must match [a-zA-Z_][a-zA-Z_0-9]*. In the following description on these attributes, host may be an actual host name or a comma separated list of attribute value pairs specified in COATTRIBUTES.

SEE ALSO

nmake(1), ksh(1), ss(1)

IMPLEMENTATION

version
coshell (AT&T Research) 2007-10-23
author
Glenn Fowler <gsf@research.att.com >
copyright
Copyright © 1990-2009 AT&T Intellectual Property
license
http://www.opensource.org/licenses/cpl1.0.txt