<refentry id="glib-running" revision="17 Jan 2002"><refmeta><refentrytitle>Running GLib Applications</refentrytitle><manvolnum>3</manvolnum><refmiscinfo>GLib Library</refmiscinfo></refmeta><refnamediv><refname>Running GLib Applications</refname><refpurpose>How to run and debug your GLib application</refpurpose></refnamediv><refsect1><title>Running and debugging GLib Applications</title><refsect2><title>Environment variables</title><para> GLib inspects a few of environment variables in addition to standardvariables like <envar>LANG</envar>, <envar>PATH</envar> or <envar>HOME</envar>. </para><formalpara id="G_FILENAME_ENCODING">  <title><envar>G_FILENAME_ENCODING</envar></title>  <para>    This environment variable can be set to a comma-separated list of character    set names. GLib assumes that filenames are encoded in the first character     set from that list rather than in UTF-8. The special token "@locale" can be    used to specify the character set for the current locale.  </para></formalpara><formalpara id="G_BROKEN_FILENAMES">  <title><envar>G_BROKEN_FILENAMES</envar></title>  <para>    If this environment variable is set, GLib assumes that filenames are in     the locale encoding rather than in UTF-8. G_FILENAME_ENCODING takes    priority over G_BROKEN_FILENAMES.   </para></formalpara><formalpara>  <title><envar>G_MESSAGES_PREFIXED</envar></title>  <para>    A list of log levels for which messages should be prefixed by the     program name and PID of the application. The default is to prefix    everything except <literal>G_LOG_LEVEL_MESSAGE</literal> and <literal>G_LOG_LEVEL_INFO</literal>.   </para></formalpara><formalpara>  <title><envar>G_DEBUG</envar></title>  <para>    If GLib has been configured with <option>--enable-debug=yes</option>,    this variable can be set to a list of debug options, which cause GLib    to print out different types of debugging information.    <variablelist>      <varlistentry>        <term>fatal_warnings</term>        <listitem><para>Causes GLib to abort the program at the first call           to <link linkend="g-warning">g_warning</link>(). This option is            special in that it doesn't require GLib to be configured with            debugging support.</para>        </listitem>      </varlistentry>    </variablelist>  </para></formalpara><formalpara>  <title><envar>G_RANDOM_VERSION</envar></title>  <para>    If this environment variable is set to '2.0', the outdated    pseudo-random number seeding and generation algorithms from    GLib-2.0 are used instead of the new better ones. Use the GLib-2.0    algorithms only if you have sequences of numbers generated with    Glib-2.0 that you need to reproduce exactly.    </para></formalpara> <formalpara>  <title><envar>LIBCHARSET_ALIAS_DIR</envar></title>  <para>    Allows to specify a nonstandard location for the     <filename>charset.aliases</filename> file that is used by the    character set conversion routines. The default location is the     <replaceable>libdir</replaceable> specified at compilation time.  </para></formalpara> <formalpara>  <title><envar>G_WIN32_PRETEND_WIN9X</envar></title>  <para>    Setting this variable to any value forces g_win32_get_windows_version()    to return a version code for Windows 9x. This is mainly an internal     debugging aid for GTK+ and GLib developers, to be able to check the     code paths for Windows 9x.  </para></formalpara> </refsect2><refsect2><title>Traps and traces</title><para>Some code portions contain trap variables that can be set during debugging time if GLib has been configured with <option>--enable-debug=yes</option>. Such traps lead to immediate code halts to examine the current program state and backtrace.</para><para>Currently, the following trap variables exist:<programlisting>static volatile gulong g_trap_free_size;static volatile gulong g_trap_realloc_size;static volatile gulong g_trap_malloc_size;</programlisting>If set to a size > 0, <link linkend="g-free">g_free</link>(), <link linkend="g-realloc">g_realloc</link>() and <link linkend="g-malloc">g_malloc</link>() will be intercepted if the size matches the size of the corresponding memory block. This will only work with <literal>g_mem_set_vtable (glib_mem_profiler_table)</literal> upon startup though, because memory profiling is required to match on the memory block sizes.</para></refsect2></refsect1></refentry>