Shell - DTracing Shell Scripting

   These scripts trace activity of various shell programming languages,
   and make use of specific shell DTrace providers, which are either
   integrated or available for download from the shells page listed below.
   Each script has a prefix to make the shell language clear.

	http://www.opensolaris.org/os/community/dtrace/shells/

   sh - the Bourne Shell. This provider was written by Alan Hargreaves and
   is currently available both as a diff and in binary form from the shells
   page.

   Since the DTrace Shell providers are under development, there is a chance
   that they have changed slightly by the time you are reading this, causing
   these scripts to either break or behave oddly. Firstly, check for newer
   versions of the DTraceToolkit; if it hasn't been updated and you need
   to use these scripts immediately, then updating them shouldn't take
   too long. The following was the state of the providers when these scripts
   were written - check for changes and update the scripts accordingly,

	provider sh {
	    probe function-entry(file, function, lineno);
	    probe function-return(file, function, rval);
	    probe builtin-entry(file, function, lineno);
	    probe builtin-return(file, function, rval);
	    probe command-entry(file, function, lineno);
	    probe command-return(file, function, rval);
	    probe script-start(file);
	    probe script-done(file, rval);
	    probe subshell-entry(file, childpid);
	    probe subshell-return(file, rval);
	    probe line(file, lineno);
	};