1 <refentry id="glib-running" revision="17 Jan 2002">
3 <refentrytitle>Running GLib Applications</refentrytitle>
4 <manvolnum>3</manvolnum>
5 <refmiscinfo>GLib Library</refmiscinfo>
9 <refname>Running GLib Applications</refname>
11 How to run and debug your GLib application
16 <title>Running and debugging GLib Applications</title>
19 <title>Environment variables</title>
22 GLib inspects a few of environment variables in addition to standard
23 variables like <envar>LANG</envar>, <envar>PATH</envar> or <envar>HOME</envar>.
26 <formalpara id="G_FILENAME_ENCODING">
27 <title><envar>G_FILENAME_ENCODING</envar></title>
30 This environment variable can be set to a comma-separated list of character
31 set names. GLib assumes that filenames are encoded in the first character
32 set from that list rather than in UTF-8. The special token "@locale" can be
33 used to specify the character set for the current locale.
37 <formalpara id="G_BROKEN_FILENAMES">
38 <title><envar>G_BROKEN_FILENAMES</envar></title>
41 If this environment variable is set, GLib assumes that filenames are in
42 the locale encoding rather than in UTF-8. G_FILENAME_ENCODING takes
43 priority over G_BROKEN_FILENAMES.
47 <formalpara id="G_MESSAGES_PREFIXED">
48 <title><envar>G_MESSAGES_PREFIXED</envar></title>
51 A list of log levels for which messages should be prefixed by the
52 program name and PID of the application. The default is to prefix
53 everything except <literal>G_LOG_LEVEL_MESSAGE</literal> and <literal>G_LOG_LEVEL_INFO</literal>.
57 <formalpara id="G_DEBUG">
58 <title><envar>G_DEBUG</envar></title>
60 If GLib has been configured with <option>--enable-debug=yes</option>,
61 this variable can be set to a list of debug options, which cause GLib
62 to print out different types of debugging information.
65 <term>fatal_warnings</term>
66 <listitem><para>Causes GLib to abort the program at the first call
67 to <link linkend="g-warning">g_warning</link>() or
68 <link linkend="g-critical">g_critical</link>(). This option is
69 special in that it doesn't require GLib to be configured with
70 debugging support.</para>
74 <term>fatal_criticals</term>
75 <listitem><para>Causes GLib to abort the program at the first call
76 to <link linkend="g-critical">g_critical</link>(). This option is
77 special in that it doesn't require GLib to be configured with
78 debugging support.</para>
82 <term>gc-friendly</term>
85 Newly allocated memory that isn't directly initialized, as well
86 as memory being freed will be reset to 0. The point here is to
87 allow memory checkers and similar programs that use bohem GC alike
88 algorithms to produce more accurate results.
89 This option is special in that it doesn't require GLib to be
90 configured with debugging support.
98 <formalpara id="G_SLICE">
99 <title><envar>G_SLICE</envar></title>
101 This environment variable allows reconfiguration of the #GSlice
105 <term>always-malloc</term>
108 This will cause all slices allocated through g_slice_alloc() and
109 released by g_slice_free1() to be actually allocated via direct
110 calls to g_malloc() and g_free().
111 This is most useful for memory checkers and similar programs that
112 use bohem GC alike algorithms to produce more accurate results.
113 It can also be in conjunction with debugging features of the system's
114 malloc implementation such as glibc's MALLOC_CHECK_=2 to debug
115 erroneous slice allocation code.
123 <formalpara id="G_RANDOM_VERSION">
124 <title><envar>G_RANDOM_VERSION</envar></title>
127 If this environment variable is set to '2.0', the outdated
128 pseudo-random number seeding and generation algorithms from
129 GLib-2.0 are used instead of the new better ones. Use the GLib-2.0
130 algorithms only if you have sequences of numbers generated with
131 Glib-2.0 that you need to reproduce exactly.
135 <formalpara id="LIBCHARSET_ALIAS_DIR">
136 <title><envar>LIBCHARSET_ALIAS_DIR</envar></title>
139 Allows to specify a nonstandard location for the
140 <filename>charset.aliases</filename> file that is used by the
141 character set conversion routines. The default location is the
142 <replaceable>libdir</replaceable> specified at compilation time.
146 <formalpara id="G_WIN32_PRETEND_WIN9X">
147 <title><envar>G_WIN32_PRETEND_WIN9X</envar></title>
150 Setting this variable to any value forces g_win32_get_windows_version()
151 to return a version code for Windows 9x. This is mainly an internal
152 debugging aid for GTK+ and GLib developers, to be able to check the
153 code paths for Windows 9x.
160 <title>Traps and traces</title>
163 Some code portions contain trap variables that can be set during debugging
164 time if GLib has been configured with <option>--enable-debug=yes</option>.
165 Such traps lead to immediate code halts to examine the current program state
170 Currently, the following trap variables exist:
172 static volatile gulong g_trap_free_size;
173 static volatile gulong g_trap_realloc_size;
174 static volatile gulong g_trap_malloc_size;
176 If set to a size > 0, <link linkend="g-free">g_free</link>(),
177 <link linkend="g-realloc">g_realloc</link>() and
178 <link linkend="g-malloc">g_malloc</link>() will be intercepted if the size
179 matches the size of the corresponding memory block. This will only work with
180 <literal>g_mem_set_vtable (glib_mem_profiler_table)</literal> upon startup
181 though, because memory profiling is required to match on the memory block sizes.