|
|
| (10 intermediate revisions by 7 users not shown) |
| Line 1: |
Line 1: |
| {{Template:I18n/Language_Navigation_Bar|Development/Tutorials/Debugging/Using Error Messages}} | | {{Moved To Community | Guidelines_and_HOWTOs/Debugging }} |
| | |
| When you start a konsole and type the commands to start an application you
| |
| will see all sorts of statements are printed in the konsole while the
| |
| application is running. All applications print these messages, to look
| |
| at them you have to know where to look. The application will have to be
| |
| compiled with the debugging enabled. So using a precompiled package from a distribution
| |
| probably will not give you this information. If you compiled the application
| |
| yourself, make sure the configure option "<tt>--disable-debug</tt>" was not used.
| |
| | |
| In KDE all debugging text-output can be switched on or off based on so
| |
| called '''areas'''. One application can be one or more area. One part of the kde base libraries can be another area. Enabling/disabling these areas from being printed can be done using the '''kdebugdialog''' application. For simple debugging selecting all
| |
| sections is probably wise.
| |
| | |
| When you are debugging it is best to simply start a konsole and start the
| |
| application from there. In a konsole you could simply type:
| |
| | |
| kicker
| |
| | |
| and in the konsole kicker could return a message like:
| |
| | |
| ERROR: kicker is already running!
| |
| | |
| When a lot of output is written to the konsole it might go out of view before
| |
| you could read it, therefor it is easy to create a text file which contains
| |
| all this information, to do so type the following:
| |
| | |
| application 2>&1 | tee debug.log
| |
| | |
| where 'application' can be replaced with the application you are debugging.
| |
| Afterwards you could open the file 'debug.log' to look at the messages again.
| |
| | |
| If you are NOT starting the application from a konsole the messages will be
| |
| logged somewhere else, or they could have been discarded by the program that
| |
| started your application.
| |
| | |
| If your application is started by clicking on an icon your best bet is to check
| |
| the following log files. Beware; they contain logs for a lot of applications,
| |
| not just the application you are debugging!
| |
| | |
| '''Case 1: Graphical login (i.e. kdm, gdm, xdm, etc.'''
| |
| | |
| The debug messages get redirected into the file {{path|~/.xsession-errors}} or
| |
| {{path|~/.X.err}} in your home directory (that is with a leading dot '.' also
| |
| watch the Capital).
| |
| | |
| '''Case 2: You are using startx:'''
| |
| | |
| Use the following command to restart your session:
| |
| startx 2>&1 | tee startx.log
| |
| | |
| so that all the debug messages of applications started at KDE's startup (and
| |
| any application launched from the panel etc.) go to the file "startx.log"
| |
| | |
| == Links ==
| |
| | |
| The debug messages are usually printed in C++ with the kDebug or kWarning statement. Example:
| |
| | |
| kDebug(1210) << "arbitrary message";
| |
| kWarning(1210) << "this rather should not happen";
| |
| | |
| The number 1210 (so called ''debug area'') in this case represents kicker. You can omit the number.
| |
| | |
| See also: [http://api.kde.org/4.0-api/kdelibs-apidocs/kdecore/html/group__kdebug.html kDebug/kWarning API documentation] and [http://websvn.kde.org/trunk/KDE/kdelibs/kdecore/kdebug.areas?view=markup kdebug.areas] for list of debug areas numbers.
| |
| Note that you can use ''add_definition(-DKDE_DEFAULT_DEBUG_AREA=<number>)'' in CMakeLists.txt to specify default debug area.
| |
| | |
| | |
