Tornado

7
Debugger
Moves one level down the stack. This is the converse of the button, and
like it, affects the data you can see but not the state of your program.
This button issues the down command, and has the same effect on a
following finish or until command as down. The location of the
temporary breakpoint that is set for finish or until depends on the selected
frame, which is changed by down.
Calls up an editor (specified by your EDITOR environment variable—or vi
if EDITOR is not defined) on the current source file. To specify the starting
context, drag the editor button to a line in the region you wish to edit,
using the middle button on your mouse.
Prints a symbol’s value in the command panel. Begin by left-clicking on
the symbol of interest, in the program-display panel; the debugger
highlights the symbol. Then press this button to display its value.
This button issues the print command, and echoes the command and its
output—the symbol value—to the command panel.
Prints the value at a pointer location. This button has a similar effect to the
print button above, except that it de-references the selected symbol. Use
this button to inspect data when you have a pointer to the data, rather than
the data itself.
This button issues the print * command, and echoes the command and its
output—the value at the selected pointer location—to the command
panel.
Launches an inspection window that monitors a symbol’s current value.
This auxiliary display is automatically updated each time control returns
to the debugger.
Several different kinds of data-inspection windows are available,
depending on data structure; the debugger chooses the right one
automatically.
Figure 7-11 shows the two simplest displays: for ordinary numeric data,
and for a pointer. In both cases, the numeric value of the variable is
displayed in a small independent window. The name of the variable being
displayed appears next to the numeric value. The window’s title bar also
shows the name of the variable displayed, preceded by a parenthesized
display number. 2
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The debugger indicates whether the displayed variable is a pointer, by
placing an asterisk to its left (as with pNode in Figure 7-11). To follow a
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