Tornado

5
Shell
Notice that the -> prompt indicates we are still in the C interpreter, even though
we just executed a line of Tcl.
! CAUTION: You may not embed Tcl evaluation inside a C expression; the ? prefix
works only as the first nonblank character on a line, and passes the entire line
following it to the Tcl interpreter.
For example, you may occasionally want to use Tcl control structures to
supplement the facilities of the C interpreter. Suppose you have an application
under development that involves several collaborating tasks; in an interactive
development session, you may need to restart the whole group of tasks repeatedly.
You can define a Tcl variable with a list of all the task entry points, as follows:
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-> ? set appTasks {appFrobStart appGetStart appPutStart …}
appFrobStart appGetStart appPutStart …
Then whenever you need to restart the whole list of tasks, you can use something
like the following:
-> ? foreach it $appTasks {shParse "sp($it)"}
task spawned: id = 25e388, name = u0
task spawned: id = 259368, name = u1
task spawned: id = 254348, name = u2
task spawned: id = 24f328, name = u3
5.7.3 Tcl: Tornado Shell lnitialization
When you execute an instance of the Tornado shell, it begins by looking for a file
called .wind/windsh.tcl in two places: first under wind, and then in the directory
specified by the HOME environment variable (if that environment variable is
defined). In each of these directories, if the file exists, the shell reads and executes
its contents as Tcl expressions before beginning to interact. You can use this file to
automate any initialization steps you perform repeatedly.
You can also specify a Tcl expression to execute initially on the windsh command
line, with the option -e tclExpr. For example, you can test an initialization file before
saving it as .wind/windsh.tcl using this option, as follows:
% windsh phobos -e "source ./tcltest" &
Example 5-4
Shell Initialization File
This file causes I/O for target routines called in WindSh to be directed to the
target’s standard I/O rather than to WindSh. It changes the default C++ strategy
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