bionic (3) Devel::ptkdb.3pm.gz
NAME
Devel::ptkdb - Perl debugger using a Tk GUI
DESCRIPTION
ptkdb is a debugger for perl that uses perlTk for a user interface.
Features include:
Hot Variable Inspection
Breakpoint Control Panel
Expression List
Subroutine Tree
SYNOPSIS
To debug a script using ptkdb invoke perl like this:
perl -d:ptkdb myscript.pl
Usage
perl -d:ptkdb myscript.pl
Code Pane
Line Numbers
Line numbers are presented on the left side of the window. Lines that
have lines through them are not breakable. Lines that are plain text
are breakable. Clicking on these line numbers will insert a
breakpoint on that line and change the line number color to
$ENV{'PTKDB_BRKPT_COLOR'} (Defaults to Red). Clicking on the number
again will remove the breakpoint. If you disable the breakpoint with
the controls on the BrkPt notebook page the color will change to
$ENV{'PTKDB_DISABLEDBRKPT_COLOR'}(Defaults to Green).
Cursor Motion
If you place the cursor over a variable (i.e. $myVar, @myVar, or %myVar) and pause for a second the
debugger will evaluate the current value of the variable and pop a balloon up with the evaluated
result. This feature is not available with Tk400.
If Data::Dumper(standard with perl5.00502)is available it will be used to format the result. If
there is an active selection, the text of that selection will be evaluated.
Notebook Pane
Exprs
This is a list of expressions that are evaluated each time the
debugger stops. The results of the expresssion are presented
hierarchically for expression that result in hashes or lists. Double
clicking on such an expression will cause it to collapse; double
clicking again will cause the expression to expand. Expressions are
entered through B<Enter Expr> entry, or by Alt-E when text is
selected in the code pane.
The B<Quick Expr> entry, will take an expression, evaluate it, and
replace the entries contents with the result. The result is also
transfered to the 'clipboard' for pasting.
Subs
Displays a list of all the packages invoked with the script
heirarchially. At the bottom of the heirarchy are the subroutines
within the packages. Double click on a package to expand
it. Subroutines are listed by their full package names.
BrkPts
Presents a list of the breakpoints current in use. The pushbutton
allows a breakpoint to be 'disabled' without removing it. Expressions
can be applied to the breakpoint. If the expression evaluates to be
'true'(results in a defined value that is not 0) the debugger will
stop the script. Pressing the 'Goto' button will set the text pane
to that file and line where the breakpoint is set. Pressing the
'Delete' button will delete the breakpoint.
Menus
File Menu
About...
Presents a dialog box telling you about the version of ptkdb. It recovers your OS name, version of
perl, version of Tk, and some other information
Open
Presents a list of files that are part of the invoked perl script. Selecting a file from this list
will present this file in the text window.
Save Config...
Requires Data::Dumper. Prompts for a filename to save the configuration to. Saves the breakpoints,
expressions, eval text and window geometry. If the name given as the default is used and the script
is reinvoked, this configuration will be reloaded automatically.
B<NOTE:> You may find this preferable to using
Restore Config...
Requires Data::Dumper. Prompts for a filename to restore a configuration saved with the "Save
Config..." menu item.
Goto Line...
Prompts for a line number. Pressing the "Okay" button sends the window to the line number entered.
item Find Text...
Prompts for text to search for. Options include forward search, backwards search, and regular
expression searching.
Quit
Causes the debugger and the target script to exit.
Control Menu
Run The debugger allows the script to run to the next breakpoint or until the script exits. item Run To
Here
Runs the debugger until it comes to wherever the insertion cursor in text window is placed.
Set Breakpoint
Sets a breakpoint on the line at the insertion cursor. item Clear Breakpoint
Remove a breakpoint on the at the insertion cursor.
Clear All Breakpoints
Removes all current breakpoints
Step Over
Causes the debugger to step over the next line. If the line is a subroutine call it steps over the
call, stopping when the subroutine returns.
Step In
Causes the debugger to step into the next line. If the line is a subroutine call it steps into the
subroutine, stopping at the first executable line within the subroutine.
Return
Runs the script until it returns from the currently executing subroutine.
Restart
Saves the breakpoints and expressions in a temporary file and restarts the script from the beginning.
CAUTION: This feature will not work properly with debugging of CGI Scripts.
Stop On Warning
When "-w" is enabled the debugger will stop when warnings such as, "Use of uninitialized value at
undef_warn.pl line N" are encountered. The debugger will stop on the NEXT line of execution since
the error can't be detected until the current line has executed.
This feature can be turned on at startup by adding:
$DB::ptkdb::stop_on_warning = 1 ;
to a .ptkdbrc file
Data Menu
Enter Expression
When an expression is entered in the "Enter Expression:" text box, selecting this item will enter the
expression into the expression list. Each time the debugger stops this expression will be evaluated
and its result updated in the list window.
Delete Expression
Deletes the highlighted expression in the expression window.
Delete All Expressions
Delete all expressions in the expression window.
Expression Eval Window
Pops up a two pane window. Expressions of virtually unlimitted length can be entered in the top pane.
Pressing the 'Eval' button will cause the expression to be evaluated and its placed in the lower
pane. If Data::Dumper is available it will be used to format the resulting text. Undo is enabled for
the text in the upper pane.
HINT: You can enter multiple expressions by separating them with commas.
Use Data::Dumper for Eval Window
Enables or disables the use of Data::Dumper for formatting the results of expressions in the Eval
window.
Stack Menu
Maintains a list of the current subroutine stack each time the debugger stops. Selecting an item from
this menu will set the text in the code window to that particular subourtine entry point.
Bookmarks Menu
Maintains a list of bookmarks. The booksmarks are saved in ~/.ptkdb_bookmarks
Add Bookmark
Adds a bookmark to the bookmark list.
Options
Here is a list of the current active XResources options. Several of these can be overridden with
environmental variables. Resources can be added to .Xresources or .Xdefaults depending on your X
configuration. To enable these resources you must either restart your X server or use the xrdb -override
resFile command. xfontsel can be used to select fonts.
/*
* Perl Tk Debugger XResources.
* Note... These resources are subject to change.
*
* Use 'xfontsel' to select different fonts.
*
* Append these resource to ~/.Xdefaults | ~/.Xresources
* and use xrdb -override ~/.Xdefaults | ~/.Xresources
* to activate them.
*/
/* Set Value to se to place scrollbars on the right side of windows
CAUTION: extra whitespace at the end of the line is causing
failures with Tk800.011.
sw -> puts scrollbars on left, se puts scrollars on the right
*/
ptkdb*scrollbars: sw
/* controls where the code pane is oriented, down the left side, or across the top */
/* values can be set to left, right, top, bottom */
ptkdb*codeside: left
/*
* Background color for the balloon
* CAUTION: For certain versions of Tk trailing
* characters after the color produces an error
*/
ptkdb.frame2.frame1.rotext.balloon.background: green
ptkdb.frame2.frame1.rotext.balloon.font: fixed /* Hot Variable Balloon Font */
ptkdb.frame*font: fixed /* Menu Bar */
ptkdb.frame.menubutton.font: fixed /* File menu */
ptkdb.frame2.frame1.rotext.font: fixed /* Code Pane */
ptkdb.notebook.datapage.frame1.hlist.font: fixed /* Expression Notebook Page */
ptkdb.notebook.subspage*font: fixed /* Subroutine Notebook Page */
ptkdb.notebook.brkptspage*entry.font: fixed /* Delete Breakpoint Buttons */
ptkdb.notebook.brkptspage*button.font: fixed /* Breakpoint Expression Entries */
ptkdb.notebook.brkptspage*button1.font: fixed /* Breakpoint Expression Entries */
ptkdb.notebook.brkptspage*checkbutton.font: fixed /* Breakpoint Checkbuttons */
ptkdb.notebook.brkptspage*label.font: fixed /* Breakpoint Checkbuttons */
ptkdb.toplevel.frame.textundo.font: fixed /* Eval Expression Entry Window */
ptkdb.toplevel.frame1.text.font: fixed /* Eval Expression Results Window */
ptkdb.toplevel.button.font: fixed /* "Eval..." Button */
ptkdb.toplevel.button1.font: fixed /* "Clear Eval" Button */
ptkdb.toplevel.button2.font: fixed /* "Clear Results" Button */
ptkdb.toplevel.button3.font: fixed /* "Clear Dismiss" Button */
/*
* Background color for where the debugger has stopped
*/
ptkdb*stopcolor: blue
/*
* Background color for set breakpoints
*/
ptkdb*breaktagcolor*background: yellow
ptkdb*disabledbreaktagcolor*background: white
/*
* Font for where the debugger has stopped
*/
ptkdb*stopfont: -*-fixed-bold-*-*-*-*-*-*-*-*-*-*-*
/*
* Background color for the search tag
*/
ptkdb*searchtagcolor: green
Environmental Variables
PTKDB_BRKPT_COLOR
Sets the background color of a set breakpoint
PTKDB_DISABLEDBRKPT_COLOR
Sets the background color of a disabled breakpoint
PTKDB_CODE_FONT
Sets the font of the Text in the code pane.
PTKDB_CODE_SIDE
Sets which side the code pane is packed onto. Defaults to 'left'. Can be set to 'left', 'right',
'top', 'bottom'.
Overrides the Xresource ptkdb*codeside: side.
PTKDB_EXPRESSION_FONT
Sets the font used in the expression notebook page.
PTKDB_EVAL_FONT
Sets the font used in the Expression Eval Window
PTKDB_EVAL_DUMP_INDENT
Sets the value used for Data::Dumper 'indent' setting. See man Data::Dumper
PTKDB_SCROLLBARS_ONRIGHT
A non-zero value Sets the scrollbars of all windows to be on the
right side of the window. Useful for Windows users using ptkdb in an
X environment.
PTKDB_LINENUMBER_FORMAT
Sets the format of line numbers on the left side of the window. Default value is %05d. useful if
you have a script that contains more than 99999 lines.
PTKDB_DISPLAY
Sets the X display that the ptkdb window will appear on when invoked. Useful for debugging CGI
scripts on remote systems.
PTKDB_BOOKMARKS_PATH
Sets the path of the bookmarks file. Default is $ENV{'HOME'}/.ptkdb_bookmarks
PTKDB_STOP_TAG_COLOR
Sets the color that highlights the line where the debugger is stopped
FILES
.ptkdbrc
If this file is present in ~/ or in the directory where perl is invoked the file will be read and
executed as a perl script before the debugger makes its initial stop at startup. There are several 'api'
calls that can be used with such scripts. There is an internal variable $DB::no_stop_at_start that may be
set to non-zero to prevent the debugger from stopping at the first line of the script. This is useful
for debugging CGI scripts.
There is a system ptkdbrc file in $PREFIX/lib/perl5/$VERS/Devel/ptkdbrc
brkpt($fname, @lines)
Sets breakspoints on the list of lines in $fname. A warning message is generated if a line is not
breakable.
condbrkpt($fname, @($line, $expr) )
Sets conditional breakpoints in $fname on pairs of $line and $expr. A warning message is generated if
a line is not breakable. NOTE: the validity of the expression will not be determined until execution
of that particular line.
brkonsub(@names)
Sets a breakpoint on each subroutine name listed. A warning message is generated if a subroutine does
not exist. NOTE: for a script with no other packages the default package is "main::" and the
subroutines would be "main::mySubs".
brkonsub_regex(@regExprs)
Uses the list of @regExprs as a list of regular expressions to set breakpoints. Sets breakpoints on
every subroutine that matches any of the listed regular expressions.
textTagConfigure(tag, ?option?, ?value?)
Allows the user to format the text in the code window. The option value pairs are the same values as
the option for the tagConfigure method documented in Tk::Text. Currently the following tags are in
effect:
'code' Format for code in the text pane
'stoppt' Format applied to the line where the debugger is currently stopped
'breakableLine' Format applied to line numbers where the code is 'breakable'
'nonbreakableLine' Format applied to line numbers where the code is no breakable
'breaksetLine' Format applied to line numbers were a breakpoint is set
'breakdisabledLine' Format applied to line numbers were a disabled breakpoint is set
'search_tag' Format applied to text when located by a search.
Example:
#
# Turns off the overstrike on lines that you can't set a breakpoint on
# and makes the text color yellow.
#
textTagConfigure('nonbreakableLine', -overstrike => 0, -foreground => "yellow") ;
add_exprs(@exprList)
Add a list of expressions to the 'Exprs' window. NOTE: use the single quote character \' to prevent
the expression from being "evaluated" in the string context.
Example:
#
# Adds the $_ and @_ expressions to the active list
#
add_exprs('$_', '@_') ;
NOTES
Debugging Other perlTk Applications
ptkdb can be used to debug other perlTk applications if some cautions are observed. Basically, do not
click the mouse in the application's window(s) when you've entered the debugger and do not click in the
debugger's window(s) while the application is running. Doing either one is not necessarily fatal, but it
can confuse things that are going on and produce unexpected results.
Be aware that most perlTk applications have a central event loop. User actions, such as mouse clicks,
key presses, window exposures, etc will generate 'events' that the script will process. When a perlTk
application is running, its 'MainLoop' call will accept these events and then dispatch them to
appropriate callbacks associated with the appropriate widgets.
Ptkdb has its own event loop that runs whenever you've stopped at a breakpoint and entered the debugger.
However, it can accept events that are generated by other perlTk windows and dispatch their callbacks.
The problem here is that the application is supposed to be 'stopped', and logically the application
should not be able to process events.
A future version of ptkdb will have an extension that will 'filter' events so that application events are
not processed while the debugger is active, and debugger events will not be processed while the target
script is active.
Debugging CGI Scripts
One advantage of ptkdb over the builtin debugger(-d) is that it can be used to debug CGI perl scripts as
they run on a web server. Be sure that that your web server's perl instalation includes Tk.
Change your
#! /usr/local/bin/perl
to
#! /usr/local/bin/perl -d:ptkdb
TIP: You can debug scripts remotely if you're using a unix based Xserver and where you are authoring the
script has an Xserver. The Xserver can be another unix workstation, a Macintosh or Win32 platform with
an appropriate X package. In your script insert the following BEGIN subroutine:
sub BEGIN {
$ENV{'DISPLAY'} = "myHostname:0.0" ;
}
Be sure that your web server has permission to open windows on your Xserver (see the xhost manpage).
Access your web page with your browswer and 'submit' the script as normal. The ptkdb window should
appear on myHostname's monitor. At this point you can start debugging your script. Be aware that your
browser may timeout waiting for the script to run.
To expedite debugging you may want to setup your breakpoints in advance with a .ptkdbrc file and use the
$DB::no_stop_at_start variable. NOTE: for debugging web scripts you may have to have the .ptkdbrc file
installed in the server account's home directory (~www) or whatever username your webserver is running
under. Also try installing a .ptkdbrc file in the same directory as the target script.
KNOWN PROBLEMS
Breakpoint Controls
If the size of the right hand pane is too small the breakpoint controls are not visible. The
breakpoints are still there, the window may have to be enlarged in order for them to be visible.
Balloons and Tk400
The Balloons in Tk400 will not work with ptkdb. All other functions are supported, but the Balloons
require Tk800 or higher.
AUTHOR
Andrew E. Page, aepage@users.sourceforge.net
ACKNOWLEDGEMENTS
Matthew Persico For suggestions, and beta testing.
BUG REPORTING
Please report bugs through the following URL:
http://sourceforge.net/tracker/?atid=437609&group_id=43854&func=browse