dtspcdenv(special file)

NAME
dtspcdenv — environment Variable File for the CDE Subprocess Control Service

DESCRIPTION

The CDE Subprocess Control service provides the ability for a process running on one system to invoke another process on a different system. By default, the environment variables of the parent process are passed unmodified to the child process (on the remote host); however, there are some environment variables that are given special handling. In addition, the user or system administrator can specify environment variables that should be modified when they are passed to the child process.

The system-wide environment files are: /etc/dt/config/dtspcdenv and /usr/dt/config/dtspcdenv and the user-specific environment file is: $HOME/.dt/dtspcdenv. The file /usr/dt/config/dtspcdenv is created when CDE is installed. This file may be overwritten by subsequent CDE installations. Consequently, local variable definitions should be placed in the file /etc/dt/config/dtspcdenv because this file is not overwritten during installation.

The environment variable files are evaluated in the following order:

local host: /usr/dt/config/dtspcdenv
local host: /etc/dt/config/dtspcdenv
local host: $HOME/.dt/dtspcdenv
remote host: /usr/dt/config/dtspcdenv
remote host: /etc/dt/config/dtspcdenv
remote host: $HOME/.dt/dtspcdenv

The precedence occurs in the reverse order of evaluation. Thus, variables in the remote host's $HOME/.dt/dtspcdenv file have the highest precedence and variables in the local host's /etc/dt/config/dtspcdenv file have the lowest precedence. In this context, the local host is the host where a CDE client is running and the remote host is the host where a remote process will be started (on behalf of the local client).

Lines beginning with a numer symbol (#) are considered comments and are not processed.

The syntax for a non-commented line is:

VAR_NAME=some_value

where VAR_NAME is the name of an environment variable and some_value is the value assigned to the variable.

If some_value contains a variable reference, the reference will be replaced by the variable's value. For example, if a CDE client has the following definition in its environment:

PATH=/bin:/sbin:/usr/local/bin

and the following definition occurs in one of the environment files:

PATH=/opt/foo/bin:$PATH

then before the remote process is executed, PATH will be expanded to:

PATH=/opt/foo/bin:/bin:/sbin:/usr/local/bin

The environment variable names may consist of letters, digits or underscores and may be enclosed in curly braces. The environment variable files may contain "unset <variable_name>" commands to prevent an environment variable from being propagated to the remote process. For example, the following line would prevent the variable LIB_PATH from being propagated to the remote process:

unset LIB_PATH

ENVIRONMENT VARIABLES

The dtspcd daemon treats the following variables specially:

DISPLAY
    If DISPLAY is set to "unix:<n>", "local:<n>" or ":<n>" (where <n> is the screen number), then before the remote process is executed, DISPLAY is changed to the name of the local host and the screen number is preserved.

HOME
    Before the remote process is executed, HOME is set to the value of the user's home directory in the password file on the remote host.

SHELL
    If SHELL is not in the parent processes environment, SHELL is set to the value of the user's shell in the password file on the remote host.

PWD The variable PWD is not propagated to the remote host. Note that the above variables will be overridden by their corresponding definitions in an environment file.

EXAMPLES

The following definition sets the variable FOO_BIN_PATH to the value /var/foo/bin: FOO_BIN_PATH=/var/foo/bin

FILES

/usr/dt/config/dtspcdenv
    System-wide, installed environment variable definitions used when a process is executed

/etc/dt/config/dtspcdenv
    System-wide, locally defined environment variable definitions used when a process is executed

$HOME/.dt/dtspcdenv
    User-specific environment variable definitions used when a process is executed

SEE ALSO

dtspcd(1m).