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/* GLIB - Library of useful routines for C programming
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
/*
* Modified by the GLib Team and others 1997-2000. See the AUTHORS
* file for a list of people on the GLib Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GLib at ftp://ftp.gtk.org/pub/gtk/.
*/
/*
* MT safe
*/
/**
* SECTION:messages
* @Title: Message Output and Debugging Functions
* @Short_description: functions to output messages and help debug applications
*
* These functions provide support for outputting messages.
*
* The g_return family of macros (g_return_if_fail(),
* g_return_val_if_fail(), g_return_if_reached(),
* g_return_val_if_reached()) should only be used for programming
* errors, a typical use case is checking for invalid parameters at
* the beginning of a public function. They should not be used if
* you just mean "if (error) return", they should only be used if
* you mean "if (bug in program) return". The program behavior is
* generally considered undefined after one of these checks fails.
* They are not intended for normal control flow, only to give a
* perhaps-helpful warning before giving up.
*
* Structured logging output is supported using g_log_structured(). This differs
* from the traditional g_log() API in that log messages are handled as a
* collection of key–value pairs representing individual pieces of information,
* rather than as a single string containing all the information in an arbitrary
* format.
*
* The convenience macros g_info(), g_message(), g_debug(), g_warning() and g_error()
* will use the traditional g_log() API unless you define the symbol
* %G_LOG_USE_STRUCTURED before including `glib.h`. But note that even messages
* logged through the traditional g_log() API are ultimatively passed to
* g_log_structured(), so that all log messages end up in same destination.
* If %G_LOG_USE_STRUCTURED is defined, g_test_expect_message() will become
* ineffective for the wrapper macros g_warning() and friends (see
* [Testing for Messages][testing-for-messages]).
*
* The support for structured logging was motivated by the following needs (some
* of which were supported previously; others weren’t):
* * Support for multiple logging levels.
* * Structured log support with the ability to add `MESSAGE_ID`s (see
* g_log_structured()).
* * Moving the responsibility for filtering log messages from the program to
* the log viewer — instead of libraries and programs installing log handlers
* (with g_log_set_handler()) which filter messages before output, all log
* messages are outputted, and the log viewer program (such as `journalctl`)
* must filter them. This is based on the idea that bugs are sometimes hard
* to reproduce, so it is better to log everything possible and then use
* tools to analyse the logs than it is to not be able to reproduce a bug to
* get additional log data. Code which uses logging in performance-critical
* sections should compile out the g_log_structured() calls in
* release builds, and compile them in in debugging builds.
* * A single writer function which handles all log messages in a process, from
* all libraries and program code; rather than multiple log handlers with
* poorly defined interactions between them. This allows a program to easily
* change its logging policy by changing the writer function, for example to
* log to an additional location or to change what logging output fallbacks
* are used. The log writer functions provided by GLib are exposed publicly
* so they can be used from programs’ log writers. This allows log writer
* policy and implementation to be kept separate.
* * If a library wants to add standard information to all of its log messages
* (such as library state) or to redact private data (such as passwords or
* network credentials), it should use a wrapper function around its
* g_log_structured() calls or implement that in the single log writer
* function.
* * If a program wants to pass context data from a g_log_structured() call to
* its log writer function so that, for example, it can use the correct
* server connection to submit logs to, that user data can be passed as a
* zero-length #GLogField to g_log_structured_array().
* * Color output needed to be supported on the terminal, to make reading
* through logs easier.
*
* ## Using Structured Logging ## {#using-structured-logging}
*
* To use structured logging (rather than the old-style logging), either use
* the g_log_structured() and g_log_structured_array() functions; or define
* `G_LOG_USE_STRUCTURED` before including any GLib header, and use the
* g_message(), g_debug(), g_error() (etc.) macros.
*
* You do not need to define `G_LOG_USE_STRUCTURED` to use g_log_structured(),
* but it is a good idea to avoid confusion.
*
* ## Log Domains ## {#log-domains}
*
* Log domains may be used to broadly split up the origins of log messages.
* Typically, there are one or a few log domains per application or library.
* %G_LOG_DOMAIN should be used to define the default log domain for the current
* compilation unit — it is typically defined at the top of a source file, or in
* the preprocessor flags for a group of source files.
*
* Log domains must be unique, and it is recommended that they are the
* application or library name, optionally followed by a hyphen and a sub-domain
* name. For example, `bloatpad` or `bloatpad-io`.
*
* ## Debug Message Output ## {#debug-message-output}
*
* The default log functions (g_log_default_handler() for the old-style API and
* g_log_writer_default() for the structured API) both drop debug and
* informational messages by default, unless the log domains of those messages
* are listed in the `G_MESSAGES_DEBUG` environment variable (or it is set to
* `all`).
*
* It is recommended that custom log writer functions re-use the
* `G_MESSAGES_DEBUG` environment variable, rather than inventing a custom one,
* so that developers can re-use the same debugging techniques and tools across
* projects. Since GLib 2.68, this can be implemented by dropping messages
* for which g_log_writer_default_would_drop() returns %TRUE.
*
* ## Testing for Messages ## {#testing-for-messages}
*
* With the old g_log() API, g_test_expect_message() and
* g_test_assert_expected_messages() could be used in simple cases to check
* whether some code under test had emitted a given log message. These
* functions have been deprecated with the structured logging API, for several
* reasons:
* * They relied on an internal queue which was too inflexible for many use
* cases, where messages might be emitted in several orders, some
* messages might not be emitted deterministically, or messages might be
* emitted by unrelated log domains.
* * They do not support structured log fields.
* * Examining the log output of code is a bad approach to testing it, and
* while it might be necessary for legacy code which uses g_log(), it should
* be avoided for new code using g_log_structured().
*
* They will continue to work as before if g_log() is in use (and
* %G_LOG_USE_STRUCTURED is not defined). They will do nothing if used with the
* structured logging API.
*
* Examining the log output of code is discouraged: libraries should not emit to
* `stderr` during defined behaviour, and hence this should not be tested. If
* the log emissions of a library during undefined behaviour need to be tested,
* they should be limited to asserting that the library aborts and prints a
* suitable error message before aborting. This should be done with
* g_test_trap_assert_stderr().
*
* If it is really necessary to test the structured log messages emitted by a
* particular piece of code – and the code cannot be restructured to be more
* suitable to more conventional unit testing – you should write a custom log
* writer function (see g_log_set_writer_func()) which appends all log messages
* to a queue. When you want to check the log messages, examine and clear the
* queue, ignoring irrelevant log messages (for example, from log domains other
* than the one under test).
*/
#include "config.h"
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>
#include <locale.h>
#include <errno.h>
#if defined(__linux__) && !defined(__BIONIC__)
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <fcntl.h>
#include <sys/uio.h>
#endif
#include "glib-init.h"
#include "galloca.h"
#include "gbacktrace.h"
#include "gcharset.h"
#include "gconvert.h"
#include "genviron.h"
#include "gmain.h"
#include "gmem.h"
#include "gprintfint.h"
#include "gtestutils.h"
#include "gthread.h"
#include "gstrfuncs.h"
#include "gstring.h"
#include "gpattern.h"
#include "gthreadprivate.h"
#ifdef G_OS_UNIX
#include <unistd.h>
#endif
#ifdef G_OS_WIN32
#include <process.h> /* For getpid() */
#include <io.h>
# include <windows.h>
#ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING
#define ENABLE_VIRTUAL_TERMINAL_PROCESSING 0x0004
#endif
#if defined (_MSC_VER) && (_MSC_VER >=1400)
/* This is ugly, but we need it for isatty() in case we have bad fd's,
* otherwise Windows will abort() the program on msvcrt80.dll and later
*/
#include <crtdbg.h>
_GLIB_EXTERN void
myInvalidParameterHandler(const wchar_t *expression,
const wchar_t *function,
const wchar_t *file,
unsigned int line,
uintptr_t pReserved)
{
}
#endif
#include "gwin32.h"
#endif
/**
* G_LOG_DOMAIN:
*
* Defines the log domain. See [Log Domains](#log-domains).
*
* Libraries should define this so that any messages
* which they log can be differentiated from messages from other
* libraries and application code. But be careful not to define
* it in any public header files.
*
* Log domains must be unique, and it is recommended that they are the
* application or library name, optionally followed by a hyphen and a sub-domain
* name. For example, `bloatpad` or `bloatpad-io`.
*
* If undefined, it defaults to the default %NULL (or `""`) log domain; this is
* not advisable, as it cannot be filtered against using the `G_MESSAGES_DEBUG`
* environment variable.
*
* For example, GTK+ uses this in its `Makefile.am`:
* |[
* AM_CPPFLAGS = -DG_LOG_DOMAIN=\"Gtk\"
* ]|
*
* Applications can choose to leave it as the default %NULL (or `""`)
* domain. However, defining the domain offers the same advantages as
* above.
*
*/
/**
* G_LOG_FATAL_MASK:
*
* GLib log levels that are considered fatal by default.
*
* This is not used if structured logging is enabled; see
* [Using Structured Logging][using-structured-logging].
*/
/**
* GLogFunc:
* @log_domain: the log domain of the message
* @log_level: the log level of the message (including the
* fatal and recursion flags)
* @message: the message to process
* @user_data: user data, set in g_log_set_handler()
*
* Specifies the prototype of log handler functions.
*
* The default log handler, g_log_default_handler(), automatically appends a
* new-line character to @message when printing it. It is advised that any
* custom log handler functions behave similarly, so that logging calls in user
* code do not need modifying to add a new-line character to the message if the
* log handler is changed.
*
* This is not used if structured logging is enabled; see
* [Using Structured Logging][using-structured-logging].
*/
/**
* GLogLevelFlags:
* @G_LOG_FLAG_RECURSION: internal flag
* @G_LOG_FLAG_FATAL: internal flag
* @G_LOG_LEVEL_ERROR: log level for errors, see g_error().
* This level is also used for messages produced by g_assert().
* @G_LOG_LEVEL_CRITICAL: log level for critical warning messages, see
* g_critical().
* This level is also used for messages produced by g_return_if_fail()
* and g_return_val_if_fail().
* @G_LOG_LEVEL_WARNING: log level for warnings, see g_warning()
* @G_LOG_LEVEL_MESSAGE: log level for messages, see g_message()
* @G_LOG_LEVEL_INFO: log level for informational messages, see g_info()
* @G_LOG_LEVEL_DEBUG: log level for debug messages, see g_debug()
* @G_LOG_LEVEL_MASK: a mask including all log levels
*
* Flags specifying the level of log messages.
*
* It is possible to change how GLib treats messages of the various
* levels using g_log_set_handler() and g_log_set_fatal_mask().
*/
/**
* G_LOG_LEVEL_USER_SHIFT:
*
* Log levels below 1<<G_LOG_LEVEL_USER_SHIFT are used by GLib.
* Higher bits can be used for user-defined log levels.
*/
/**
* g_message:
* @...: format string, followed by parameters to insert
* into the format string (as with printf())
*
* A convenience function/macro to log a normal message.
*
* If g_log_default_handler() is used as the log handler function, a new-line
* character will automatically be appended to @..., and need not be entered
* manually.
*
* If structured logging is enabled, this will use g_log_structured();
* otherwise it will use g_log(). See
* [Using Structured Logging][using-structured-logging].
*/
/**
* g_warning:
* @...: format string, followed by parameters to insert
* into the format string (as with printf())
*
* A convenience function/macro to log a warning message. The message should
* typically *not* be translated to the user's language.
*
* This is not intended for end user error reporting. Use of #GError is
* preferred for that instead, as it allows calling functions to perform actions
* conditional on the type of error.
*
* Warning messages are intended to be used in the event of unexpected
* external conditions (system misconfiguration, missing files,
* other trusted programs violating protocol, invalid contents in
* trusted files, etc.)
*
* If attempting to deal with programmer errors (for example, incorrect function
* parameters) then you should use %G_LOG_LEVEL_CRITICAL instead.
*
* g_warn_if_reached() and g_warn_if_fail() log at %G_LOG_LEVEL_WARNING.
*
* You can make warnings fatal at runtime by setting the `G_DEBUG`
* environment variable (see
* [Running GLib Applications](glib-running.html)):
*
* |[
* G_DEBUG=fatal-warnings gdb ./my-program
* ]|
*
* Any unrelated failures can be skipped over in
* [gdb](https://www.gnu.org/software/gdb/) using the `continue` command.
*
* If g_log_default_handler() is used as the log handler function,
* a newline character will automatically be appended to @..., and
* need not be entered manually.
*
* If structured logging is enabled, this will use g_log_structured();
* otherwise it will use g_log(). See
* [Using Structured Logging][using-structured-logging].
*/
/**
* g_critical:
* @...: format string, followed by parameters to insert
* into the format string (as with printf())
*
* Logs a "critical warning" (#G_LOG_LEVEL_CRITICAL).
*
* Critical warnings are intended to be used in the event of an error
* that originated in the current process (a programmer error).
* Logging of a critical error is by definition an indication of a bug
* somewhere in the current program (or its libraries).
*
* g_return_if_fail(), g_return_val_if_fail(), g_return_if_reached() and
* g_return_val_if_reached() log at %G_LOG_LEVEL_CRITICAL.
*
* You can make critical warnings fatal at runtime by
* setting the `G_DEBUG` environment variable (see
* [Running GLib Applications](glib-running.html)):
*
* |[
* G_DEBUG=fatal-warnings gdb ./my-program
* ]|
*
* You can also use g_log_set_always_fatal().
*
* Any unrelated failures can be skipped over in
* [gdb](https://www.gnu.org/software/gdb/) using the `continue` command.
*
* The message should typically *not* be translated to the
* user's language.
*
* If g_log_default_handler() is used as the log handler function, a new-line
* character will automatically be appended to @..., and need not be entered
* manually.
*
* If structured logging is enabled, this will use g_log_structured();
* otherwise it will use g_log(). See
* [Using Structured Logging][using-structured-logging].
*/
/**
* g_error:
* @...: format string, followed by parameters to insert
* into the format string (as with printf())
*
* A convenience function/macro to log an error message. The message should
* typically *not* be translated to the user's language.
*
* This is not intended for end user error reporting. Use of #GError is
* preferred for that instead, as it allows calling functions to perform actions
* conditional on the type of error.
*
* Error messages are always fatal, resulting in a call to G_BREAKPOINT()
* to terminate the application. This function will
* result in a core dump; don't use it for errors you expect.
* Using this function indicates a bug in your program, i.e.
* an assertion failure.
*
* If g_log_default_handler() is used as the log handler function, a new-line
* character will automatically be appended to @..., and need not be entered
* manually.
*
* If structured logging is enabled, this will use g_log_structured();
* otherwise it will use g_log(). See
* [Using Structured Logging][using-structured-logging].
*/
/**
* g_info:
* @...: format string, followed by parameters to insert
* into the format string (as with printf())
*
* A convenience function/macro to log an informational message. Seldom used.
*
* If g_log_default_handler() is used as the log handler function, a new-line
* character will automatically be appended to @..., and need not be entered
* manually.
*
* Such messages are suppressed by the g_log_default_handler() and
* g_log_writer_default() unless the `G_MESSAGES_DEBUG` environment variable is
* set appropriately.
*
* If structured logging is enabled, this will use g_log_structured();
* otherwise it will use g_log(). See
* [Using Structured Logging][using-structured-logging].
*
* Since: 2.40
*/
/**
* g_debug:
* @...: format string, followed by parameters to insert
* into the format string (as with printf())
*
* A convenience function/macro to log a debug message. The message should
* typically *not* be translated to the user's language.
*
* If g_log_default_handler() is used as the log handler function, a new-line
* character will automatically be appended to @..., and need not be entered
* manually.
*
* Such messages are suppressed by the g_log_default_handler() and
* g_log_writer_default() unless the `G_MESSAGES_DEBUG` environment variable is
* set appropriately.
*
* If structured logging is enabled, this will use g_log_structured();
* otherwise it will use g_log(). See
* [Using Structured Logging][using-structured-logging].
*
* Since: 2.6
*/
/* --- structures --- */
typedef struct _GLogDomain GLogDomain;
typedef struct _GLogHandler GLogHandler;
struct _GLogDomain
{
gchar *log_domain;
GLogLevelFlags fatal_mask;
GLogHandler *handlers;
GLogDomain *next;
};
struct _GLogHandler
{
guint id;
GLogLevelFlags log_level;
GLogFunc log_func;
gpointer data;
GDestroyNotify destroy;
GLogHandler *next;
};
/* --- variables --- */
static GMutex g_messages_lock;
static GLogDomain *g_log_domains = NULL;
static GPrintFunc glib_print_func = NULL;
static GPrintFunc glib_printerr_func = NULL;
static GPrivate g_log_depth;
static GPrivate g_log_structured_depth;
static GLogFunc default_log_func = g_log_default_handler;
static gpointer default_log_data = NULL;
static GTestLogFatalFunc fatal_log_func = NULL;
static gpointer fatal_log_data;
static GLogWriterFunc log_writer_func = g_log_writer_default;
static gpointer log_writer_user_data = NULL;
static GDestroyNotify log_writer_user_data_free = NULL;
/* --- functions --- */
static void _g_log_abort (gboolean breakpoint);
static void
_g_log_abort (gboolean breakpoint)
{
gboolean debugger_present;
if (g_test_subprocess ())
{
/* If this is a test case subprocess then it probably caused
* this error message on purpose, so just exit() rather than
* abort()ing, to avoid triggering any system crash-reporting
* daemon.
*/
_exit (1);
}
#ifdef G_OS_WIN32
debugger_present = IsDebuggerPresent ();
#else
/* Assume GDB is attached. */
debugger_present = TRUE;
#endif /* !G_OS_WIN32 */
if (debugger_present && breakpoint)
G_BREAKPOINT ();
else
g_abort ();
}
#ifdef G_OS_WIN32
static gboolean win32_keep_fatal_message = FALSE;
/* This default message will usually be overwritten. */
/* Yes, a fixed size buffer is bad. So sue me. But g_error() is never
* called with huge strings, is it?
*/
static gchar fatal_msg_buf[1000] = "Unspecified fatal error encountered, aborting.";
static gchar *fatal_msg_ptr = fatal_msg_buf;
#undef write
static inline int
dowrite (int fd,
const void *buf,
unsigned int len)
{
if (win32_keep_fatal_message)
{
memcpy (fatal_msg_ptr, buf, len);
fatal_msg_ptr += len;
*fatal_msg_ptr = 0;
return len;
}
write (fd, buf, len);
return len;
}
#define write(fd, buf, len) dowrite(fd, buf, len)
#endif
static void
write_string (FILE *stream,
const gchar *string)
{
fputs (string, stream);
}
static void
write_string_sized (FILE *stream,
const gchar *string,
gssize length)
{
/* Is it nul-terminated? */
if (length < 0)
write_string (stream, string);
else
fwrite (string, 1, length, stream);
}
static GLogDomain*
g_log_find_domain_L (const gchar *log_domain)
{
GLogDomain *domain;
domain = g_log_domains;
while (domain)
{
if (strcmp (domain->log_domain, log_domain) == 0)
return domain;
domain = domain->next;
}
return NULL;
}
static GLogDomain*
g_log_domain_new_L (const gchar *log_domain)
{
GLogDomain *domain;
domain = g_new (GLogDomain, 1);
domain->log_domain = g_strdup (log_domain);
domain->fatal_mask = G_LOG_FATAL_MASK;
domain->handlers = NULL;
domain->next = g_log_domains;
g_log_domains = domain;
return domain;
}
static void
g_log_domain_check_free_L (GLogDomain *domain)
{
if (domain->fatal_mask == G_LOG_FATAL_MASK &&
domain->handlers == NULL)
{
GLogDomain *last, *work;
last = NULL;
work = g_log_domains;
while (work)
{
if (work == domain)
{
if (last)
last->next = domain->next;
else
g_log_domains = domain->next;
g_free (domain->log_domain);
g_free (domain);
break;
}
last = work;
work = last->next;
}
}
}
static GLogFunc
g_log_domain_get_handler_L (GLogDomain *domain,
GLogLevelFlags log_level,
gpointer *data)
{
if (domain && log_level)
{
GLogHandler *handler;
handler = domain->handlers;
while (handler)
{
if ((handler->log_level & log_level) == log_level)
{
*data = handler->data;
return handler->log_func;
}
handler = handler->next;
}
}
*data = default_log_data;
return default_log_func;
}
/**
* g_log_set_always_fatal:
* @fatal_mask: the mask containing bits set for each level
* of error which is to be fatal
*
* Sets the message levels which are always fatal, in any log domain.
* When a message with any of these levels is logged the program terminates.
* You can only set the levels defined by GLib to be fatal.
* %G_LOG_LEVEL_ERROR is always fatal.
*
* You can also make some message levels fatal at runtime by setting
* the `G_DEBUG` environment variable (see
* [Running GLib Applications](glib-running.html)).
*
* Libraries should not call this function, as it affects all messages logged
* by a process, including those from other libraries.
*
* Structured log messages (using g_log_structured() and
* g_log_structured_array()) are fatal only if the default log writer is used;
* otherwise it is up to the writer function to determine which log messages
* are fatal. See [Using Structured Logging][using-structured-logging].
*
* Returns: the old fatal mask
*/
GLogLevelFlags
g_log_set_always_fatal (GLogLevelFlags fatal_mask)
{
GLogLevelFlags old_mask;
/* restrict the global mask to levels that are known to glib
* since this setting applies to all domains
*/
fatal_mask &= (1 << G_LOG_LEVEL_USER_SHIFT) - 1;
/* force errors to be fatal */
fatal_mask |= G_LOG_LEVEL_ERROR;
/* remove bogus flag */
fatal_mask &= ~G_LOG_FLAG_FATAL;
g_mutex_lock (&g_messages_lock);
old_mask = g_log_always_fatal;
g_log_always_fatal = fatal_mask;
g_mutex_unlock (&g_messages_lock);
return old_mask;
}
/**
* g_log_set_fatal_mask:
* @log_domain: the log domain
* @fatal_mask: the new fatal mask
*
* Sets the log levels which are fatal in the given domain.
* %G_LOG_LEVEL_ERROR is always fatal.
*
* This has no effect on structured log messages (using g_log_structured() or
* g_log_structured_array()). To change the fatal behaviour for specific log
* messages, programs must install a custom log writer function using
* g_log_set_writer_func(). See
* [Using Structured Logging][using-structured-logging].
*
* This function is mostly intended to be used with
* %G_LOG_LEVEL_CRITICAL. You should typically not set
* %G_LOG_LEVEL_WARNING, %G_LOG_LEVEL_MESSAGE, %G_LOG_LEVEL_INFO or
* %G_LOG_LEVEL_DEBUG as fatal except inside of test programs.
*
* Returns: the old fatal mask for the log domain
*/
GLogLevelFlags
g_log_set_fatal_mask (const gchar *log_domain,
GLogLevelFlags fatal_mask)
{
GLogLevelFlags old_flags;
GLogDomain *domain;
if (!log_domain)
log_domain = "";
/* force errors to be fatal */
fatal_mask |= G_LOG_LEVEL_ERROR;
/* remove bogus flag */
fatal_mask &= ~G_LOG_FLAG_FATAL;
g_mutex_lock (&g_messages_lock);
domain = g_log_find_domain_L (log_domain);
if (!domain)
domain = g_log_domain_new_L (log_domain);
old_flags = domain->fatal_mask;
domain->fatal_mask = fatal_mask;
g_log_domain_check_free_L (domain);
g_mutex_unlock (&g_messages_lock);
return old_flags;
}
/**
* g_log_set_handler:
* @log_domain: (nullable): the log domain, or %NULL for the default ""
* application domain
* @log_levels: the log levels to apply the log handler for.
* To handle fatal and recursive messages as well, combine
* the log levels with the #G_LOG_FLAG_FATAL and
* #G_LOG_FLAG_RECURSION bit flags.
* @log_func: the log handler function
* @user_data: data passed to the log handler
*
* Sets the log handler for a domain and a set of log levels.
* To handle fatal and recursive messages the @log_levels parameter
* must be combined with the #G_LOG_FLAG_FATAL and #G_LOG_FLAG_RECURSION
* bit flags.
*
* Note that since the #G_LOG_LEVEL_ERROR log level is always fatal, if
* you want to set a handler for this log level you must combine it with
* #G_LOG_FLAG_FATAL.
*
* This has no effect if structured logging is enabled; see
* [Using Structured Logging][using-structured-logging].
*
* Here is an example for adding a log handler for all warning messages
* in the default domain:
* |[<!-- language="C" -->
* g_log_set_handler (NULL, G_LOG_LEVEL_WARNING | G_LOG_FLAG_FATAL
* | G_LOG_FLAG_RECURSION, my_log_handler, NULL);
* ]|
*
* This example adds a log handler for all critical messages from GTK+:
* |[<!-- language="C" -->
* g_log_set_handler ("Gtk", G_LOG_LEVEL_CRITICAL | G_LOG_FLAG_FATAL
* | G_LOG_FLAG_RECURSION, my_log_handler, NULL);
* ]|
*
* This example adds a log handler for all messages from GLib:
* |[<!-- language="C" -->
* g_log_set_handler ("GLib", G_LOG_LEVEL_MASK | G_LOG_FLAG_FATAL
* | G_LOG_FLAG_RECURSION, my_log_handler, NULL);
* ]|
*
* Returns: the id of the new handler
*/
guint
g_log_set_handler (const gchar *log_domain,
GLogLevelFlags log_levels,
GLogFunc log_func,
gpointer user_data)
{
return g_log_set_handler_full (log_domain, log_levels, log_func, user_data, NULL);
}
/**
* g_log_set_handler_full: (rename-to g_log_set_handler)
* @log_domain: (nullable): the log domain, or %NULL for the default ""
* application domain
* @log_levels: the log levels to apply the log handler for.
* To handle fatal and recursive messages as well, combine
* the log levels with the #G_LOG_FLAG_FATAL and
* #G_LOG_FLAG_RECURSION bit flags.
* @log_func: the log handler function
* @user_data: data passed to the log handler
* @destroy: destroy notify for @user_data, or %NULL
*
* Like g_log_set_handler(), but takes a destroy notify for the @user_data.
*
* This has no effect if structured logging is enabled; see
* [Using Structured Logging][using-structured-logging].
*
* Returns: the id of the new handler
*
* Since: 2.46
*/
guint
g_log_set_handler_full (const gchar *log_domain,
GLogLevelFlags log_levels,
GLogFunc log_func,
gpointer user_data,
GDestroyNotify destroy)
{
static guint handler_id = 0;
GLogDomain *domain;
GLogHandler *handler;
g_return_val_if_fail ((log_levels & G_LOG_LEVEL_MASK) != 0, 0);
g_return_val_if_fail (log_func != NULL, 0);
if (!log_domain)
log_domain = "";
handler = g_new (GLogHandler, 1);
g_mutex_lock (&g_messages_lock);
domain = g_log_find_domain_L (log_domain);
if (!domain)
domain = g_log_domain_new_L (log_domain);
handler->id = ++handler_id;
handler->log_level = log_levels;
handler->log_func = log_func;
handler->data = user_data;
handler->destroy = destroy;
handler->next = domain->handlers;
domain->handlers = handler;
g_mutex_unlock (&g_messages_lock);
return handler_id;
}
/**
* g_log_set_default_handler:
* @log_func: the log handler function
* @user_data: data passed to the log handler
*
* Installs a default log handler which is used if no
* log handler has been set for the particular log domain
* and log level combination. By default, GLib uses
* g_log_default_handler() as default log handler.
*
* This has no effect if structured logging is enabled; see
* [Using Structured Logging][using-structured-logging].
*
* Returns: the previous default log handler
*
* Since: 2.6
*/
GLogFunc
g_log_set_default_handler (GLogFunc log_func,
gpointer user_data)
{
GLogFunc old_log_func;
g_mutex_lock (&g_messages_lock);
old_log_func = default_log_func;
default_log_func = log_func;
default_log_data = user_data;
g_mutex_unlock (&g_messages_lock);
return old_log_func;
}
/**
* g_test_log_set_fatal_handler:
* @log_func: the log handler function.
* @user_data: data passed to the log handler.
*
* Installs a non-error fatal log handler which can be
* used to decide whether log messages which are counted
* as fatal abort the program.
*
* The use case here is that you are running a test case
* that depends on particular libraries or circumstances
* and cannot prevent certain known critical or warning
* messages. So you install a handler that compares the
* domain and message to precisely not abort in such a case.
*
* Note that the handler is reset at the beginning of
* any test case, so you have to set it inside each test
* function which needs the special behavior.
*
* This handler has no effect on g_error messages.
*
* This handler also has no effect on structured log messages (using
* g_log_structured() or g_log_structured_array()). To change the fatal
* behaviour for specific log messages, programs must install a custom log
* writer function using g_log_set_writer_func().See
* [Using Structured Logging][using-structured-logging].
*
* Since: 2.22
**/
void
g_test_log_set_fatal_handler (GTestLogFatalFunc log_func,
gpointer user_data)
{
g_mutex_lock (&g_messages_lock);
fatal_log_func = log_func;
fatal_log_data = user_data;
g_mutex_unlock (&g_messages_lock);
}
/**
* g_log_remove_handler:
* @log_domain: the log domain
* @handler_id: the id of the handler, which was returned
* in g_log_set_handler()
*
* Removes the log handler.
*
* This has no effect if structured logging is enabled; see
* [Using Structured Logging][using-structured-logging].
*/
void
g_log_remove_handler (const gchar *log_domain,
guint handler_id)
{
GLogDomain *domain;
g_return_if_fail (handler_id > 0);
if (!log_domain)
log_domain = "";
g_mutex_lock (&g_messages_lock);
domain = g_log_find_domain_L (log_domain);
if (domain)
{
GLogHandler *work, *last;
last = NULL;
work = domain->handlers;
while (work)
{
if (work->id == handler_id)
{
if (last)
last->next = work->next;
else
domain->handlers = work->next;
g_log_domain_check_free_L (domain);
g_mutex_unlock (&g_messages_lock);
if (work->destroy)
work->destroy (work->data);
g_free (work);
return;
}
last = work;
work = last->next;
}
}
g_mutex_unlock (&g_messages_lock);
g_warning ("%s: could not find handler with id '%d' for domain \"%s\"",
G_STRLOC, handler_id, log_domain);
}
#define CHAR_IS_SAFE(wc) (!((wc < 0x20 && wc != '\t' && wc != '\n' && wc != '\r') || \
(wc == 0x7f) || \
(wc >= 0x80 && wc < 0xa0)))
static gchar*
strdup_convert (const gchar *string,
const gchar *charset)
{
if (!g_utf8_validate (string, -1, NULL))
{
GString *gstring = g_string_new ("[Invalid UTF-8] ");
guchar *p;
for (p = (guchar *)string; *p; p++)
{
if (CHAR_IS_SAFE(*p) &&
!(*p == '\r' && *(p + 1) != '\n') &&
*p < 0x80)
g_string_append_c (gstring, *p);
else
g_string_append_printf (gstring, "\\x%02x", (guint)(guchar)*p);
}
return g_string_free (gstring, FALSE);
}
else
{
GError *err = NULL;
gchar *result = g_convert_with_fallback (string, -1, charset, "UTF-8", "?", NULL, NULL, &err);
if (result)
return result;
else
{
/* Not thread-safe, but doesn't matter if we print the warning twice
*/
static gboolean warned = FALSE;
if (!warned)
{
warned = TRUE;
_g_fprintf (stderr, "GLib: Cannot convert message: %s\n", err->message);
}
g_error_free (err);
return g_strdup (string);
}
}
}
/* For a radix of 8 we need at most 3 output bytes for 1 input
* byte. Additionally we might need up to 2 output bytes for the
* readix prefix and 1 byte for the trailing NULL.
*/
#define FORMAT_UNSIGNED_BUFSIZE ((GLIB_SIZEOF_LONG * 3) + 3)
static void
format_unsigned (gchar *buf,
gulong num,
guint radix)
{
gulong tmp;
gchar c;
gint i, n;
/* we may not call _any_ GLib functions here (or macros like g_return_if_fail()) */
if (radix != 8 && radix != 10 && radix != 16)
{
*buf = '\000';
return;
}
if (!num)
{
*buf++ = '0';
*buf = '\000';
return;
}
if (radix == 16)
{
*buf++ = '0';
*buf++ = 'x';
}
else if (radix == 8)
{
*buf++ = '0';
}
n = 0;
tmp = num;
while (tmp)
{
tmp /= radix;
n++;
}
i = n;
/* Again we can't use g_assert; actually this check should _never_ fail. */
if (n > FORMAT_UNSIGNED_BUFSIZE - 3)
{
*buf = '\000';
return;
}
while (num)
{
i--;
c = (num % radix);
if (c < 10)
buf[i] = c + '0';
else
buf[i] = c + 'a' - 10;
num /= radix;
}
buf[n] = '\000';
}
/* string size big enough to hold level prefix */
#define STRING_BUFFER_SIZE (FORMAT_UNSIGNED_BUFSIZE + 32)
#define ALERT_LEVELS (G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL | G_LOG_LEVEL_WARNING)
/* these are emitted by the default log handler */
#define DEFAULT_LEVELS (G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL | G_LOG_LEVEL_WARNING | G_LOG_LEVEL_MESSAGE)
/* these are filtered by G_MESSAGES_DEBUG by the default log handler */
#define INFO_LEVELS (G_LOG_LEVEL_INFO | G_LOG_LEVEL_DEBUG)
static const gchar *log_level_to_color (GLogLevelFlags log_level,
gboolean use_color);
static const gchar *color_reset (gboolean use_color);
static gboolean gmessages_use_stderr = FALSE;
/**
* g_log_writer_default_set_use_stderr:
* @use_stderr: If %TRUE, use `stderr` for log messages that would
* normally have appeared on `stdout`
*
* Configure whether the built-in log functions
* (g_log_default_handler() for the old-style API, and both
* g_log_writer_default() and g_log_writer_standard_streams() for the
* structured API) will output all log messages to `stderr`.
*
* By default, log messages of levels %G_LOG_LEVEL_INFO and
* %G_LOG_LEVEL_DEBUG are sent to `stdout`, and other log messages are
* sent to `stderr`. This is problematic for applications that intend
* to reserve `stdout` for structured output such as JSON or XML.
*
* This function sets global state. It is not thread-aware, and should be
* called at the very start of a program, before creating any other threads
* or creating objects that could create worker threads of their own.
*
* Since: 2.68
*/
void
g_log_writer_default_set_use_stderr (gboolean use_stderr)
{
g_return_if_fail (g_thread_n_created () == 0);
gmessages_use_stderr = use_stderr;
}
static FILE *
mklevel_prefix (gchar level_prefix[STRING_BUFFER_SIZE],
GLogLevelFlags log_level,
gboolean use_color)
{
gboolean to_stdout = !gmessages_use_stderr;
/* we may not call _any_ GLib functions here */
strcpy (level_prefix, log_level_to_color (log_level, use_color));
switch (log_level & G_LOG_LEVEL_MASK)
{
case G_LOG_LEVEL_ERROR:
strcat (level_prefix, "ERROR");
to_stdout = FALSE;
break;
case G_LOG_LEVEL_CRITICAL:
strcat (level_prefix, "CRITICAL");
to_stdout = FALSE;
break;
case G_LOG_LEVEL_WARNING:
strcat (level_prefix, "WARNING");
to_stdout = FALSE;
break;
case G_LOG_LEVEL_MESSAGE:
strcat (level_prefix, "Message");
to_stdout = FALSE;
break;
case G_LOG_LEVEL_INFO:
strcat (level_prefix, "INFO");
break;
case G_LOG_LEVEL_DEBUG:
strcat (level_prefix, "DEBUG");
break;
default:
if (log_level)
{
strcat (level_prefix, "LOG-");
format_unsigned (level_prefix + 4, log_level & G_LOG_LEVEL_MASK, 16);
}
else
strcat (level_prefix, "LOG");
break;
}
strcat (level_prefix, color_reset (use_color));
if (log_level & G_LOG_FLAG_RECURSION)
strcat (level_prefix, " (recursed)");
if (log_level & ALERT_LEVELS)
strcat (level_prefix, " **");
#ifdef G_OS_WIN32
if ((log_level & G_LOG_FLAG_FATAL) != 0 && !g_test_initialized ())
win32_keep_fatal_message = TRUE;
#endif
return to_stdout ? stdout : stderr;
}
typedef struct {
gchar *log_domain;
GLogLevelFlags log_level;
gchar *pattern;
} GTestExpectedMessage;
static GSList *expected_messages = NULL;
/**
* g_logv:
* @log_domain: (nullable): the log domain, or %NULL for the default ""
* application domain
* @log_level: the log level
* @format: the message format. See the printf() documentation
* @args: the parameters to insert into the format string
*
* Logs an error or debugging message.
*
* If the log level has been set as fatal, G_BREAKPOINT() is called
* to terminate the program. See the documentation for G_BREAKPOINT() for
* details of the debugging options this provides.
*
* If g_log_default_handler() is used as the log handler function, a new-line
* character will automatically be appended to @..., and need not be entered
* manually.
*
* If [structured logging is enabled][using-structured-logging] this will
* output via the structured log writer function (see g_log_set_writer_func()).
*/
void
g_logv (const gchar *log_domain,
GLogLevelFlags log_level,
const gchar *format,
va_list args)
{
gboolean was_fatal = (log_level & G_LOG_FLAG_FATAL) != 0;
gboolean was_recursion = (log_level & G_LOG_FLAG_RECURSION) != 0;
gchar buffer[1025], *msg, *msg_alloc = NULL;
gint i;
log_level &= G_LOG_LEVEL_MASK;
if (!log_level)
return;
if (log_level & G_LOG_FLAG_RECURSION)
{
/* we use a stack buffer of fixed size, since we're likely
* in an out-of-memory situation
*/
gsize size G_GNUC_UNUSED;
size = _g_vsnprintf (buffer, 1024, format, args);
msg = buffer;
}
else
msg = msg_alloc = g_strdup_vprintf (format, args);
if (expected_messages)
{
GTestExpectedMessage *expected = expected_messages->data;
if (g_strcmp0 (expected->log_domain, log_domain) == 0 &&
((log_level & expected->log_level) == expected->log_level) &&
g_pattern_match_simple (expected->pattern, msg))
{
expected_messages = g_slist_delete_link (expected_messages,
expected_messages);
g_free (expected->log_domain);
g_free (expected->pattern);
g_free (expected);
g_free (msg_alloc);
return;
}
else if ((log_level & G_LOG_LEVEL_DEBUG) != G_LOG_LEVEL_DEBUG)
{
gchar level_prefix[STRING_BUFFER_SIZE];
gchar *expected_message;
mklevel_prefix (level_prefix, expected->log_level, FALSE);
expected_message = g_strdup_printf ("Did not see expected message %s-%s: %s",
expected->log_domain ? expected->log_domain : "**",
level_prefix, expected->pattern);
g_log_default_handler (G_LOG_DOMAIN, G_LOG_LEVEL_CRITICAL, expected_message, NULL);
g_free (expected_message);
log_level |= G_LOG_FLAG_FATAL;
}
}
for (i = g_bit_nth_msf (log_level, -1); i >= 0; i = g_bit_nth_msf (log_level, i))
{
GLogLevelFlags test_level;
test_level = 1L << i;
if (log_level & test_level)
{
GLogDomain *domain;
GLogFunc log_func;
GLogLevelFlags domain_fatal_mask;
gpointer data = NULL;
gboolean masquerade_fatal = FALSE;
guint depth;
if (was_fatal)
test_level |= G_LOG_FLAG_FATAL;
if (was_recursion)
test_level |= G_LOG_FLAG_RECURSION;
/* check recursion and lookup handler */
g_mutex_lock (&g_messages_lock);
depth = GPOINTER_TO_UINT (g_private_get (&g_log_depth));
domain = g_log_find_domain_L (log_domain ? log_domain : "");
if (depth)
test_level |= G_LOG_FLAG_RECURSION;
depth++;
domain_fatal_mask = domain ? domain->fatal_mask : G_LOG_FATAL_MASK;
if ((domain_fatal_mask | g_log_always_fatal) & test_level)
test_level |= G_LOG_FLAG_FATAL;
if (test_level & G_LOG_FLAG_RECURSION)
log_func = _g_log_fallback_handler;
else
log_func = g_log_domain_get_handler_L (domain, test_level, &data);
domain = NULL;
g_mutex_unlock (&g_messages_lock);
g_private_set (&g_log_depth, GUINT_TO_POINTER (depth));
log_func (log_domain, test_level, msg, data);
if ((test_level & G_LOG_FLAG_FATAL)
&& !(test_level & G_LOG_LEVEL_ERROR))
{
masquerade_fatal = fatal_log_func
&& !fatal_log_func (log_domain, test_level, msg, fatal_log_data);
}
if ((test_level & G_LOG_FLAG_FATAL) && !masquerade_fatal)
{
/* MessageBox is allowed on UWP apps only when building against
* the debug CRT, which will set -D_DEBUG */
#if defined(G_OS_WIN32) && (defined(_DEBUG) || !defined(G_WINAPI_ONLY_APP))
if (win32_keep_fatal_message)
{
WCHAR *wide_msg;
wide_msg = g_utf8_to_utf16 (fatal_msg_buf, -1, NULL, NULL, NULL);
MessageBoxW (NULL, wide_msg, NULL,
MB_ICONERROR | MB_SETFOREGROUND);
g_free (wide_msg);
}
#endif
_g_log_abort (!(test_level & G_LOG_FLAG_RECURSION));
}
depth--;
g_private_set (&g_log_depth, GUINT_TO_POINTER (depth));
}
}
g_free (msg_alloc);
}
/**
* g_log:
* @log_domain: (nullable): the log domain, usually #G_LOG_DOMAIN, or %NULL
* for the default
* @log_level: the log level, either from #GLogLevelFlags
* or a user-defined level
* @format: the message format. See the printf() documentation
* @...: the parameters to insert into the format string
*
* Logs an error or debugging message.
*
* If the log level has been set as fatal, G_BREAKPOINT() is called
* to terminate the program. See the documentation for G_BREAKPOINT() for
* details of the debugging options this provides.
*
* If g_log_default_handler() is used as the log handler function, a new-line
* character will automatically be appended to @..., and need not be entered
* manually.
*
* If [structured logging is enabled][using-structured-logging] this will
* output via the structured log writer function (see g_log_set_writer_func()).
*/
void
g_log (const gchar *log_domain,
GLogLevelFlags log_level,
const gchar *format,
...)
{
va_list args;
va_start (args, format);
g_logv (log_domain, log_level, format, args);
va_end (args);
}
/* Return value must be 1 byte long (plus nul byte).
* Reference: http://man7.org/linux/man-pages/man3/syslog.3.html#DESCRIPTION
*/
static const gchar *
log_level_to_priority (GLogLevelFlags log_level)
{
if (log_level & G_LOG_LEVEL_ERROR)
return "3";
else if (log_level & G_LOG_LEVEL_CRITICAL)
return "4";
else if (log_level & G_LOG_LEVEL_WARNING)
return "4";
else if (log_level & G_LOG_LEVEL_MESSAGE)
return "5";
else if (log_level & G_LOG_LEVEL_INFO)
return "6";
else if (log_level & G_LOG_LEVEL_DEBUG)
return "7";
/* Default to LOG_NOTICE for custom log levels. */
return "5";
}
static FILE *
log_level_to_file (GLogLevelFlags log_level)
{
if (gmessages_use_stderr)
return stderr;
if (log_level & (G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL |
G_LOG_LEVEL_WARNING | G_LOG_LEVEL_MESSAGE))
return stderr;
else
return stdout;
}
static const gchar *
log_level_to_color (GLogLevelFlags log_level,
gboolean use_color)
{
/* we may not call _any_ GLib functions here */
if (!use_color)
return "";
if (log_level & G_LOG_LEVEL_ERROR)
return "\033[1;31m"; /* red */
else if (log_level & G_LOG_LEVEL_CRITICAL)
return "\033[1;35m"; /* magenta */
else if (log_level & G_LOG_LEVEL_WARNING)
return "\033[1;33m"; /* yellow */
else if (log_level & G_LOG_LEVEL_MESSAGE)
return "\033[1;32m"; /* green */
else if (log_level & G_LOG_LEVEL_INFO)
return "\033[1;32m"; /* green */
else if (log_level & G_LOG_LEVEL_DEBUG)
return "\033[1;32m"; /* green */
/* No color for custom log levels. */
return "";
}
static const gchar *
color_reset (gboolean use_color)
{
/* we may not call _any_ GLib functions here */
if (!use_color)
return "";
return "\033[0m";
}
#ifdef G_OS_WIN32
/* We might be using tty emulators such as mintty, so try to detect it, if we passed in a valid FD
* so we need to check the name of the pipe if _isatty (fd) == 0
*/
static gboolean
win32_is_pipe_tty (int fd)
{
gboolean result = FALSE;
HANDLE h_fd;
FILE_NAME_INFO *info = NULL;
gint info_size = sizeof (FILE_NAME_INFO) + sizeof (WCHAR) * MAX_PATH;
wchar_t *name = NULL;
gint length;
h_fd = (HANDLE) _get_osfhandle (fd);
if (h_fd == INVALID_HANDLE_VALUE || GetFileType (h_fd) != FILE_TYPE_PIPE)
goto done_query;
/* mintty uses a pipe, in the form of \{cygwin|msys}-xxxxxxxxxxxxxxxx-ptyN-{from|to}-master */
info = g_try_malloc (info_size);
if (info == NULL ||
!GetFileInformationByHandleEx (h_fd, FileNameInfo, info, info_size))
goto done_query;
info->FileName[info->FileNameLength / sizeof (WCHAR)] = L'\0';
name = info->FileName;
length = wcslen (L"\\cygwin-");
if (wcsncmp (name, L"\\cygwin-", length))
{
length = wcslen (L"\\msys-");
if (wcsncmp (name, L"\\msys-", length))
goto done_query;
}
name += length;
length = wcsspn (name, L"0123456789abcdefABCDEF");
if (length != 16)
goto done_query;
name += length;
length = wcslen (L"-pty");
if (wcsncmp (name, L"-pty", length))
goto done_query;
name += length;
length = wcsspn (name, L"0123456789");
if (length != 1)
goto done_query;
name += length;
length = wcslen (L"-to-master");
if (wcsncmp (name, L"-to-master", length))
{
length = wcslen (L"-from-master");
if (wcsncmp (name, L"-from-master", length))
goto done_query;
}
result = TRUE;
done_query:
if (info != NULL)
g_free (info);
return result;
}
#endif
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wformat-nonliteral"
/**
* g_log_structured:
* @log_domain: log domain, usually %G_LOG_DOMAIN
* @log_level: log level, either from #GLogLevelFlags, or a user-defined
* level
* @...: key-value pairs of structured data to add to the log entry, followed
* by the key "MESSAGE", followed by a printf()-style message format,
* followed by parameters to insert in the format string
*
* Log a message with structured data. The message will be passed through to
* the log writer set by the application using g_log_set_writer_func(). If the
* message is fatal (i.e. its log level is %G_LOG_LEVEL_ERROR), the program will
* be aborted by calling G_BREAKPOINT() at the end of this function. If the log writer returns
* %G_LOG_WRITER_UNHANDLED (failure), no other fallback writers will be tried.
* See the documentation for #GLogWriterFunc for information on chaining
* writers.
*
* The structured data is provided as key–value pairs, where keys are UTF-8
* strings, and values are arbitrary pointers — typically pointing to UTF-8
* strings, but that is not a requirement. To pass binary (non-nul-terminated)
* structured data, use g_log_structured_array(). The keys for structured data
* should follow the [systemd journal
* fields](https://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html)
* specification. It is suggested that custom keys are namespaced according to
* the code which sets them. For example, custom keys from GLib all have a
* `GLIB_` prefix.
*
* The @log_domain will be converted into a `GLIB_DOMAIN` field. @log_level will
* be converted into a
* [`PRIORITY`](https://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html#PRIORITY=)
* field. The format string will have its placeholders substituted for the provided
* values and be converted into a
* [`MESSAGE`](https://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html#MESSAGE=)
* field.
*
* Other fields you may commonly want to pass into this function:
*
* * [`MESSAGE_ID`](https://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html#MESSAGE_ID=)
* * [`CODE_FILE`](https://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html#CODE_FILE=)
* * [`CODE_LINE`](https://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html#CODE_LINE=)
* * [`CODE_FUNC`](https://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html#CODE_FUNC=)
* * [`ERRNO`](https://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html#ERRNO=)
*
* Note that `CODE_FILE`, `CODE_LINE` and `CODE_FUNC` are automatically set by
* the logging macros, G_DEBUG_HERE(), g_message(), g_warning(), g_critical(),
* g_error(), etc, if the symbols `G_LOG_USE_STRUCTURED` is defined before including
* glib.h.
*
* For example:
* |[<!-- language="C" -->
* g_log_structured (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,
* "MESSAGE_ID", "06d4df59e6c24647bfe69d2c27ef0b4e",
* "MY_APPLICATION_CUSTOM_FIELD", "some debug string",
* "MESSAGE", "This is a debug message about pointer %p and integer %u.",
* some_pointer, some_integer);
* ]|
*
* Note that each `MESSAGE_ID` must be [uniquely and randomly
* generated](https://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html#MESSAGE_ID=).
* If adding a `MESSAGE_ID`, consider shipping a [message
* catalog](https://www.freedesktop.org/wiki/Software/systemd/catalog/) with
* your software.
*
* To pass a user data pointer to the log writer function which is specific to
* this logging call, you must use g_log_structured_array() and pass the pointer
* as a field with #GLogField.length set to zero, otherwise it will be
* interpreted as a string.
*
* For example:
* |[<!-- language="C" -->
* const GLogField fields[] = {
* { "MESSAGE", "This is a debug message.", -1 },
* { "MESSAGE_ID", "fcfb2e1e65c3494386b74878f1abf893", -1 },
* { "MY_APPLICATION_CUSTOM_FIELD", "some debug string", -1 },
* { "MY_APPLICATION_STATE", state_object, 0 },
* };
* g_log_structured_array (G_LOG_LEVEL_DEBUG, fields, G_N_ELEMENTS (fields));
* ]|
*
* Note also that, even if no other structured fields are specified, there
* must always be a `MESSAGE` key before the format string. The `MESSAGE`-format
* pair has to be the last of the key-value pairs, and `MESSAGE` is the only
* field for which printf()-style formatting is supported.
*
* The default writer function for `stdout` and `stderr` will automatically
* append a new-line character after the message, so you should not add one
* manually to the format string.
*
* Since: 2.50
*/
void
g_log_structured (const gchar *log_domain,
GLogLevelFlags log_level,
...)
{
va_list args;
gchar buffer[1025], *message_allocated = NULL;
const char *format;
const gchar *message;
gpointer p;
gsize n_fields, i;
GLogField stack_fields[16];
GLogField *fields = stack_fields;
GLogField *fields_allocated = NULL;
GArray *array = NULL;
va_start (args, log_level);
/* MESSAGE and PRIORITY are a given */
n_fields = 2;
if (log_domain)
n_fields++;
for (p = va_arg (args, gchar *), i = n_fields;
strcmp (p, "MESSAGE") != 0;
p = va_arg (args, gchar *), i++)
{
GLogField field;
const gchar *key = p;
gconstpointer value = va_arg (args, gpointer);
field.key = key;
field.value = value;
field.length = -1;
if (i < 16)
stack_fields[i] = field;
else
{
/* Don't allow dynamic allocation, since we're likely
* in an out-of-memory situation. For lack of a better solution,
* just ignore further key-value pairs.
*/
if (log_level & G_LOG_FLAG_RECURSION)
continue;
if (i == 16)
{
array = g_array_sized_new (FALSE, FALSE, sizeof (GLogField), 32);
g_array_append_vals (array, stack_fields, 16);
}
g_array_append_val (array, field);
}
}
n_fields = i;
if (array)
fields = fields_allocated = (GLogField *) g_array_free (array, FALSE);
format = va_arg (args, gchar *);
if (log_level & G_LOG_FLAG_RECURSION)
{
/* we use a stack buffer of fixed size, since we're likely
* in an out-of-memory situation
*/
gsize size G_GNUC_UNUSED;
size = _g_vsnprintf (buffer, sizeof (buffer), format, args);
message = buffer;
}
else
{
message = message_allocated = g_strdup_vprintf (format, args);
}
/* Add MESSAGE, PRIORITY and GLIB_DOMAIN. */
fields[0].key = "MESSAGE";
fields[0].value = message;
fields[0].length = -1;
fields[1].key = "PRIORITY";
fields[1].value = log_level_to_priority (log_level);
fields[1].length = -1;
if (log_domain)
{
fields[2].key = "GLIB_DOMAIN";
fields[2].value = log_domain;
fields[2].length = -1;
}
/* Log it. */
g_log_structured_array (log_level, fields, n_fields);
g_free (fields_allocated);
g_free (message_allocated);
va_end (args);
}
/**
* g_log_variant:
* @log_domain: (nullable): log domain, usually %G_LOG_DOMAIN
* @log_level: log level, either from #GLogLevelFlags, or a user-defined
* level
* @fields: a dictionary (#GVariant of the type %G_VARIANT_TYPE_VARDICT)
* containing the key-value pairs of message data.
*
* Log a message with structured data, accepting the data within a #GVariant. This
* version is especially useful for use in other languages, via introspection.
*
* The only mandatory item in the @fields dictionary is the "MESSAGE" which must
* contain the text shown to the user.
*
* The values in the @fields dictionary are likely to be of type String
* (#G_VARIANT_TYPE_STRING). Array of bytes (#G_VARIANT_TYPE_BYTESTRING) is also
* supported. In this case the message is handled as binary and will be forwarded
* to the log writer as such. The size of the array should not be higher than
* %G_MAXSSIZE. Otherwise it will be truncated to this size. For other types
* g_variant_print() will be used to convert the value into a string.
*
* For more details on its usage and about the parameters, see g_log_structured().
*
* Since: 2.50
*/
void
g_log_variant (const gchar *log_domain,
GLogLevelFlags log_level,
GVariant *fields)
{
GVariantIter iter;
GVariant *value;
gchar *key;
GArray *fields_array;
GLogField field;
GSList *values_list, *print_list;
g_return_if_fail (g_variant_is_of_type (fields, G_VARIANT_TYPE_VARDICT));
values_list = print_list = NULL;
fields_array = g_array_new (FALSE, FALSE, sizeof (GLogField));
field.key = "PRIORITY";
field.value = log_level_to_priority (log_level);
field.length = -1;
g_array_append_val (fields_array, field);
if (log_domain)
{
field.key = "GLIB_DOMAIN";
field.value = log_domain;
field.length = -1;
g_array_append_val (fields_array, field);
}
g_variant_iter_init (&iter, fields);
while (g_variant_iter_next (&iter, "{&sv}", &key, &value))
{
gboolean defer_unref = TRUE;
field.key = key;
field.length = -1;
if (g_variant_is_of_type (value, G_VARIANT_TYPE_STRING))
{
field.value = g_variant_get_string (value, NULL);
}
else if (g_variant_is_of_type (value, G_VARIANT_TYPE_BYTESTRING))
{
gsize s;
field.value = g_variant_get_fixed_array (value, &s, sizeof (guchar));
if (G_LIKELY (s <= G_MAXSSIZE))
{
field.length = s;
}
else
{
_g_fprintf (stderr,
"Byte array too large (%" G_GSIZE_FORMAT " bytes)"
" passed to g_log_variant(). Truncating to " G_STRINGIFY (G_MAXSSIZE)
" bytes.", s);
field.length = G_MAXSSIZE;
}
}
else
{
char *s = g_variant_print (value, FALSE);
field.value = s;
print_list = g_slist_prepend (print_list, s);
defer_unref = FALSE;
}
g_array_append_val (fields_array, field);
if (G_LIKELY (defer_unref))
values_list = g_slist_prepend (values_list, value);
else
g_variant_unref (value);
}
/* Log it. */
g_log_structured_array (log_level, (GLogField *) fields_array->data, fields_array->len);
g_array_free (fields_array, TRUE);
g_slist_free_full (values_list, (GDestroyNotify) g_variant_unref);
g_slist_free_full (print_list, g_free);
}
#pragma GCC diagnostic pop
static GLogWriterOutput _g_log_writer_fallback (GLogLevelFlags log_level,
const GLogField *fields,
gsize n_fields,
gpointer user_data);
/**
* g_log_structured_array:
* @log_level: log level, either from #GLogLevelFlags, or a user-defined
* level
* @fields: (array length=n_fields): key–value pairs of structured data to add
* to the log message
* @n_fields: number of elements in the @fields array
*
* Log a message with structured data. The message will be passed through to the
* log writer set by the application using g_log_set_writer_func(). If the
* message is fatal (i.e. its log level is %G_LOG_LEVEL_ERROR), the program will
* be aborted at the end of this function.
*
* See g_log_structured() for more documentation.
*
* This assumes that @log_level is already present in @fields (typically as the
* `PRIORITY` field).
*
* Since: 2.50
*/
void
g_log_structured_array (GLogLevelFlags log_level,
const GLogField *fields,
gsize n_fields)
{
GLogWriterFunc writer_func;
gpointer writer_user_data;
gboolean recursion;
guint depth;
if (n_fields == 0)
return;
/* Check for recursion and look up the writer function. */
depth = GPOINTER_TO_UINT (g_private_get (&g_log_structured_depth));
recursion = (depth > 0);
g_mutex_lock (&g_messages_lock);
writer_func = recursion ? _g_log_writer_fallback : log_writer_func;
writer_user_data = log_writer_user_data;
g_mutex_unlock (&g_messages_lock);
/* Write the log entry. */
g_private_set (&g_log_structured_depth, GUINT_TO_POINTER (++depth));
g_assert (writer_func != NULL);
writer_func (log_level, fields, n_fields, writer_user_data);
g_private_set (&g_log_structured_depth, GUINT_TO_POINTER (--depth));
/* Abort if the message was fatal. */
if (log_level & G_LOG_FATAL_MASK)
_g_log_abort (!(log_level & G_LOG_FLAG_RECURSION));
}
/* Semi-private helper function to implement the g_message() (etc.) macros
* with support for G_GNUC_PRINTF so that @message_format can be checked
* with -Wformat. */
void
g_log_structured_standard (const gchar *log_domain,
GLogLevelFlags log_level,
const gchar *file,
const gchar *line,
const gchar *func,
const gchar *message_format,
...)
{
GLogField fields[] =
{
{ "PRIORITY", log_level_to_priority (log_level), -1 },
{ "CODE_FILE", file, -1 },
{ "CODE_LINE", line, -1 },
{ "CODE_FUNC", func, -1 },
/* Filled in later: */
{ "MESSAGE", NULL, -1 },
/* If @log_domain is %NULL, we will not pass this field: */
{ "GLIB_DOMAIN", log_domain, -1 },
};
gsize n_fields;
gchar *message_allocated = NULL;
gchar buffer[1025];
va_list args;
va_start (args, message_format);
if (log_level & G_LOG_FLAG_RECURSION)
{
/* we use a stack buffer of fixed size, since we're likely
* in an out-of-memory situation
*/
gsize size G_GNUC_UNUSED;
size = _g_vsnprintf (buffer, sizeof (buffer), message_format, args);
fields[4].value = buffer;
}
else
{
fields[4].value = message_allocated = g_strdup_vprintf (message_format, args);
}
va_end (args);
n_fields = G_N_ELEMENTS (fields) - ((log_domain == NULL) ? 1 : 0);
g_log_structured_array (log_level, fields, n_fields);
g_free (message_allocated);
}
/**
* g_log_set_writer_func:
* @func: log writer function, which must not be %NULL
* @user_data: (closure func): user data to pass to @func
* @user_data_free: (destroy func): function to free @user_data once it’s
* finished with, if non-%NULL
*
* Set a writer function which will be called to format and write out each log
* message. Each program should set a writer function, or the default writer
* (g_log_writer_default()) will be used.
*
* Libraries **must not** call this function — only programs are allowed to
* install a writer function, as there must be a single, central point where
* log messages are formatted and outputted.
*
* There can only be one writer function. It is an error to set more than one.
*
* Since: 2.50
*/
void
g_log_set_writer_func (GLogWriterFunc func,
gpointer user_data,
GDestroyNotify user_data_free)
{
g_return_if_fail (func != NULL);
g_mutex_lock (&g_messages_lock);
log_writer_func = func;
log_writer_user_data = user_data;
log_writer_user_data_free = user_data_free;
g_mutex_unlock (&g_messages_lock);
}
/**
* g_log_writer_supports_color:
* @output_fd: output file descriptor to check
*
* Check whether the given @output_fd file descriptor supports ANSI color
* escape sequences. If so, they can safely be used when formatting log
* messages.
*
* Returns: %TRUE if ANSI color escapes are supported, %FALSE otherwise
* Since: 2.50
*/
gboolean
g_log_writer_supports_color (gint output_fd)
{
#ifdef G_OS_WIN32
gboolean result = FALSE;
#if (defined (_MSC_VER) && _MSC_VER >= 1400)
_invalid_parameter_handler oldHandler, newHandler;
int prev_report_mode = 0;
#endif
#endif
g_return_val_if_fail (output_fd >= 0, FALSE);
/* FIXME: This check could easily be expanded in future to be more robust
* against different types of terminal, which still vary in their color
* support. cmd.exe on Windows, for example, supports ANSI colors only
* from Windows 10 onwards; bash on Windows has always supported ANSI colors.
* The Windows 10 color support is supported on:
* -Output in the cmd.exe, MSYS/Cygwin standard consoles.
* -Output in the cmd.exe, MSYS/Cygwin piped to the less program.
* but not:
* -Output in Cygwin via mintty (https://github.com/mintty/mintty/issues/482)
* -Color code output when output redirected to file (i.e. program 2> some.txt)
*
* On UNIX systems, we probably want to use the functions from terminfo to
* work out whether colors are supported.
*
* Some examples:
* - https://github.com/chalk/supports-color/blob/9434c93918301a6b47faa01999482adfbf1b715c/index.js#L61
* - http://stackoverflow.com/questions/16755142/how-to-make-win32-console-recognize-ansi-vt100-escape-sequences
* - http://blog.mmediasys.com/2010/11/24/we-all-love-colors/
* - http://unix.stackexchange.com/questions/198794/where-does-the-term-environment-variable-default-get-set
*/
#ifdef G_OS_WIN32
#if (defined (_MSC_VER) && _MSC_VER >= 1400)
/* Set up our empty invalid parameter handler, for isatty(),
* in case of bad fd's passed in for isatty(), so that
* msvcrt80.dll+ won't abort the program
*/
newHandler = myInvalidParameterHandler;
oldHandler = _set_invalid_parameter_handler (newHandler);
/* Disable the message box for assertions. */
prev_report_mode = _CrtSetReportMode(_CRT_ASSERT, 0);
#endif
if (g_win32_check_windows_version (10, 0, 0, G_WIN32_OS_ANY))
{
HANDLE h_output;
DWORD dw_mode;
if (_isatty (output_fd))
{
h_output = (HANDLE) _get_osfhandle (output_fd);
if (!GetConsoleMode (h_output, &dw_mode))
goto reset_invalid_param_handler;
if (dw_mode & ENABLE_VIRTUAL_TERMINAL_PROCESSING)
result = TRUE;
if (!SetConsoleMode (h_output, dw_mode | ENABLE_VIRTUAL_TERMINAL_PROCESSING))
goto reset_invalid_param_handler;
result = TRUE;
}
}
/* FIXME: Support colored outputs for structured logs for pre-Windows 10,
* perhaps using WriteConsoleOutput or SetConsoleTextAttribute
* (bug 775468), on standard Windows consoles, such as cmd.exe
*/
if (!result)
result = win32_is_pipe_tty (output_fd);
reset_invalid_param_handler:
#if defined (_MSC_VER) && (_MSC_VER >= 1400)
_CrtSetReportMode(_CRT_ASSERT, prev_report_mode);
_set_invalid_parameter_handler (oldHandler);
#endif
return result;
#else
return isatty (output_fd);
#endif
}
#if defined(__linux__) && !defined(__BIONIC__)
static int journal_fd = -1;
#ifndef SOCK_CLOEXEC
#define SOCK_CLOEXEC 0
#else
#define HAVE_SOCK_CLOEXEC 1
#endif
static void
open_journal (void)
{
if ((journal_fd = socket (AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0)
return;
#ifndef HAVE_SOCK_CLOEXEC
if (fcntl (journal_fd, F_SETFD, FD_CLOEXEC) < 0)
{
close (journal_fd);
journal_fd = -1;
}
#endif
}
#endif
/**
* g_log_writer_is_journald:
* @output_fd: output file descriptor to check
*
* Check whether the given @output_fd file descriptor is a connection to the
* systemd journal, or something else (like a log file or `stdout` or
* `stderr`).
*
* Invalid file descriptors are accepted and return %FALSE, which allows for
* the following construct without needing any additional error handling:
* |[<!-- language="C" -->
* is_journald = g_log_writer_is_journald (fileno (stderr));
* ]|
*
* Returns: %TRUE if @output_fd points to the journal, %FALSE otherwise
* Since: 2.50
*/
gboolean
g_log_writer_is_journald (gint output_fd)
{
#if defined(__linux__) && !defined(__BIONIC__)
/* FIXME: Use the new journal API for detecting whether we’re writing to the
* journal. See: https://github.com/systemd/systemd/issues/2473
*/
union {
struct sockaddr_storage storage;
struct sockaddr sa;
struct sockaddr_un un;
} addr;
socklen_t addr_len;
int err;
if (output_fd < 0)
return FALSE;
addr_len = sizeof(addr);
err = getpeername (output_fd, &addr.sa, &addr_len);
if (err == 0 && addr.storage.ss_family == AF_UNIX)
return g_str_has_prefix (addr.un.sun_path, "/run/systemd/journal/");
#endif
return FALSE;
}
static void escape_string (GString *string);
/**
* g_log_writer_format_fields:
* @log_level: log level, either from #GLogLevelFlags, or a user-defined
* level
* @fields: (array length=n_fields): key–value pairs of structured data forming
* the log message
* @n_fields: number of elements in the @fields array
* @use_color: %TRUE to use ANSI color escape sequences when formatting the
* message, %FALSE to not
*
* Format a structured log message as a string suitable for outputting to the
* terminal (or elsewhere). This will include the values of all fields it knows
* how to interpret, which includes `MESSAGE` and `GLIB_DOMAIN` (see the
* documentation for g_log_structured()). It does not include values from
* unknown fields.
*
* The returned string does **not** have a trailing new-line character. It is
* encoded in the character set of the current locale, which is not necessarily
* UTF-8.
*
* Returns: (transfer full): string containing the formatted log message, in
* the character set of the current locale
* Since: 2.50
*/
gchar *
g_log_writer_format_fields (GLogLevelFlags log_level,
const GLogField *fields,
gsize n_fields,
gboolean use_color)
{
gsize i;
const gchar *message = NULL;
const gchar *log_domain = NULL;
gchar level_prefix[STRING_BUFFER_SIZE];
GString *gstring;
gint64 now;
time_t now_secs;
struct tm *now_tm;
gchar time_buf[128];
/* Extract some common fields. */
for (i = 0; (message == NULL || log_domain == NULL) && i < n_fields; i++)
{
const GLogField *field = &fields[i];
if (g_strcmp0 (field->key, "MESSAGE") == 0)
message = field->value;
else if (g_strcmp0 (field->key, "GLIB_DOMAIN") == 0)
log_domain = field->value;
}
/* Format things. */
mklevel_prefix (level_prefix, log_level, use_color);
gstring = g_string_new (NULL);
if (log_level & ALERT_LEVELS)
g_string_append (gstring, "\n");
if (!log_domain)
g_string_append (gstring, "** ");
if ((g_log_msg_prefix & (log_level & G_LOG_LEVEL_MASK)) ==
(log_level & G_LOG_LEVEL_MASK))
{
const gchar *prg_name = g_get_prgname ();
gulong pid = getpid ();
if (prg_name == NULL)
g_string_append_printf (gstring, "(process:%lu): ", pid);
else
g_string_append_printf (gstring, "(%s:%lu): ", prg_name, pid);
}
if (log_domain != NULL)
{
g_string_append (gstring, log_domain);
g_string_append_c (gstring, '-');
}
g_string_append (gstring, level_prefix);
g_string_append (gstring, ": ");
/* Timestamp */
now = g_get_real_time ();
now_secs = (time_t) (now / 1000000);
now_tm = localtime (&now_secs);
strftime (time_buf, sizeof (time_buf), "%H:%M:%S", now_tm);
g_string_append_printf (gstring, "%s%s.%03d%s: ",
use_color ? "\033[34m" : "",
time_buf, (gint) ((now / 1000) % 1000),
color_reset (use_color));
if (message == NULL)
{
g_string_append (gstring, "(NULL) message");
}
else
{
GString *msg;
const gchar *charset;
msg = g_string_new (message);
escape_string (msg);
if (g_get_console_charset (&charset))
{
/* charset is UTF-8 already */
g_string_append (gstring, msg->str);
}
else
{
gchar *lstring = strdup_convert (msg->str, charset);
g_string_append (gstring, lstring);
g_free (lstring);
}
g_string_free (msg, TRUE);
}
return g_string_free (gstring, FALSE);
}
/* Enable support for the journal if we're on a recent enough Linux */
#if defined(__linux__) && !defined(__BIONIC__) && defined(HAVE_MKOSTEMP) && defined(O_CLOEXEC)
#define ENABLE_JOURNAL_SENDV
#endif
#ifdef ENABLE_JOURNAL_SENDV
static int
journal_sendv (struct iovec *iov,
gsize iovlen)
{
int buf_fd = -1;
struct msghdr mh;
struct sockaddr_un sa;
union {
struct cmsghdr cmsghdr;
guint8 buf[CMSG_SPACE(sizeof(int))];
} control;
struct cmsghdr *cmsg;
char path[] = "/dev/shm/journal.XXXXXX";
if (journal_fd < 0)
open_journal ();
if (journal_fd < 0)
return -1;
memset (&sa, 0, sizeof (sa));
sa.sun_family = AF_UNIX;
if (g_strlcpy (sa.sun_path, "/run/systemd/journal/socket", sizeof (sa.sun_path)) >= sizeof (sa.sun_path))
return -1;
memset (&mh, 0, sizeof (mh));
mh.msg_name = &sa;
mh.msg_namelen = offsetof (struct sockaddr_un, sun_path) + strlen (sa.sun_path);
mh.msg_iov = iov;
mh.msg_iovlen = iovlen;
retry:
if (sendmsg (journal_fd, &mh, MSG_NOSIGNAL) >= 0)
return 0;
if (errno == EINTR)
goto retry;
if (errno != EMSGSIZE && errno != ENOBUFS)
return -1;
/* Message was too large, so dump to temporary file
* and pass an FD to the journal
*/
if ((buf_fd = mkostemp (path, O_CLOEXEC|O_RDWR)) < 0)
return -1;
if (unlink (path) < 0)
{
close (buf_fd);
return -1;
}
if (writev (buf_fd, iov, iovlen) < 0)
{
close (buf_fd);
return -1;
}
mh.msg_iov = NULL;
mh.msg_iovlen = 0;
memset (&control, 0, sizeof (control));
mh.msg_control = &control;
mh.msg_controllen = sizeof (control);
cmsg = CMSG_FIRSTHDR (&mh);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN (sizeof (int));
memcpy (CMSG_DATA (cmsg), &buf_fd, sizeof (int));
mh.msg_controllen = cmsg->cmsg_len;
retry2:
if (sendmsg (journal_fd, &mh, MSG_NOSIGNAL) >= 0)
return 0;
if (errno == EINTR)
goto retry2;
return -1;
}
#endif /* ENABLE_JOURNAL_SENDV */
/**
* g_log_writer_journald:
* @log_level: log level, either from #GLogLevelFlags, or a user-defined
* level
* @fields: (array length=n_fields): key–value pairs of structured data forming
* the log message
* @n_fields: number of elements in the @fields array
* @user_data: user data passed to g_log_set_writer_func()
*
* Format a structured log message and send it to the systemd journal as a set
* of key–value pairs. All fields are sent to the journal, but if a field has
* length zero (indicating program-specific data) then only its key will be
* sent.
*
* This is suitable for use as a #GLogWriterFunc.
*
* If GLib has been compiled without systemd support, this function is still
* defined, but will always return %G_LOG_WRITER_UNHANDLED.
*
* Returns: %G_LOG_WRITER_HANDLED on success, %G_LOG_WRITER_UNHANDLED otherwise
* Since: 2.50
*/
GLogWriterOutput
g_log_writer_journald (GLogLevelFlags log_level,
const GLogField *fields,
gsize n_fields,
gpointer user_data)
{
#ifdef ENABLE_JOURNAL_SENDV
const char equals = '=';
const char newline = '\n';
gsize i, k;
struct iovec *iov, *v;
char *buf;
gint retval;
g_return_val_if_fail (fields != NULL, G_LOG_WRITER_UNHANDLED);
g_return_val_if_fail (n_fields > 0, G_LOG_WRITER_UNHANDLED);
/* According to systemd.journal-fields(7), the journal allows fields in any
* format (including arbitrary binary), but expects text fields to be UTF-8.
* This is great, because we require input strings to be in UTF-8, so no
* conversion is necessary and we don’t need to care about the current
* locale’s character set.
*/
iov = g_alloca (sizeof (struct iovec) * 5 * n_fields);
buf = g_alloca (32 * n_fields);
k = 0;
v = iov;
for (i = 0; i < n_fields; i++)
{
guint64 length;
gboolean binary;
if (fields[i].length < 0)
{
length = strlen (fields[i].value);
binary = strchr (fields[i].value, '\n') != NULL;
}
else
{
length = fields[i].length;
binary = TRUE;
}
if (binary)
{
guint64 nstr;
v[0].iov_base = (gpointer)fields[i].key;
v[0].iov_len = strlen (fields[i].key);
v[1].iov_base = (gpointer)&newline;
v[1].iov_len = 1;
nstr = GUINT64_TO_LE(length);
memcpy (&buf[k], &nstr, sizeof (nstr));
v[2].iov_base = &buf[k];
v[2].iov_len = sizeof (nstr);
v += 3;
k += sizeof (nstr);
}
else
{
v[0].iov_base = (gpointer)fields[i].key;
v[0].iov_len = strlen (fields[i].key);
v[1].iov_base = (gpointer)&equals;
v[1].iov_len = 1;
v += 2;
}
v[0].iov_base = (gpointer)fields[i].value;
v[0].iov_len = length;
v[1].iov_base = (gpointer)&newline;
v[1].iov_len = 1;
v += 2;
}
retval = journal_sendv (iov, v - iov);
return retval == 0 ? G_LOG_WRITER_HANDLED : G_LOG_WRITER_UNHANDLED;
#else
return G_LOG_WRITER_UNHANDLED;
#endif /* ENABLE_JOURNAL_SENDV */
}
/**
* g_log_writer_standard_streams:
* @log_level: log level, either from #GLogLevelFlags, or a user-defined
* level
* @fields: (array length=n_fields): key–value pairs of structured data forming
* the log message
* @n_fields: number of elements in the @fields array
* @user_data: user data passed to g_log_set_writer_func()
*
* Format a structured log message and print it to either `stdout` or `stderr`,
* depending on its log level. %G_LOG_LEVEL_INFO and %G_LOG_LEVEL_DEBUG messages
* are sent to `stdout`, or to `stderr` if requested by
* g_log_writer_default_set_use_stderr();
* all other log levels are sent to `stderr`. Only fields
* which are understood by this function are included in the formatted string
* which is printed.
*
* If the output stream supports ANSI color escape sequences, they will be used
* in the output.
*
* A trailing new-line character is added to the log message when it is printed.
*
* This is suitable for use as a #GLogWriterFunc.
*
* Returns: %G_LOG_WRITER_HANDLED on success, %G_LOG_WRITER_UNHANDLED otherwise
* Since: 2.50
*/
GLogWriterOutput
g_log_writer_standard_streams (GLogLevelFlags log_level,
const GLogField *fields,
gsize n_fields,
gpointer user_data)
{
FILE *stream;
gchar *out = NULL; /* in the current locale’s character set */
g_return_val_if_fail (fields != NULL, G_LOG_WRITER_UNHANDLED);
g_return_val_if_fail (n_fields > 0, G_LOG_WRITER_UNHANDLED);
stream = log_level_to_file (log_level);
if (!stream || fileno (stream) < 0)
return G_LOG_WRITER_UNHANDLED;
out = g_log_writer_format_fields (log_level, fields, n_fields,
g_log_writer_supports_color (fileno (stream)));
_g_fprintf (stream, "%s\n", out);
fflush (stream);
g_free (out);
return G_LOG_WRITER_HANDLED;
}
/* The old g_log() API is implemented in terms of the new structured log API.
* However, some of the checks do not line up between the two APIs: the
* structured API only handles fatalness of messages for log levels; the old API
* handles it per-domain as well. Consequently, we need to disable fatalness
* handling in the structured log API when called from the old g_log() API.
*
* We can guarantee that g_log_default_handler() will pass GLIB_OLD_LOG_API as
* the first field to g_log_structured_array(), if that is the case.
*/
static gboolean
log_is_old_api (const GLogField *fields,
gsize n_fields)
{
return (n_fields >= 1 &&
g_strcmp0 (fields[0].key, "GLIB_OLD_LOG_API") == 0 &&
g_strcmp0 (fields[0].value, "1") == 0);
}
/*
* Internal version of g_log_writer_default_would_drop(), which can
* read from either a log_domain or an array of fields. This avoids
* having to iterate through the fields if the @log_level is sufficient
* to make the decision.
*/
static gboolean
should_drop_message (GLogLevelFlags log_level,
const char *log_domain,
const GLogField *fields,
gsize n_fields)
{
/* Disable debug message output unless specified in G_MESSAGES_DEBUG. */
if (!(log_level & DEFAULT_LEVELS) && !(log_level >> G_LOG_LEVEL_USER_SHIFT))
{
const gchar *domains;
gsize i;
domains = g_getenv ("G_MESSAGES_DEBUG");
if ((log_level & INFO_LEVELS) == 0 ||
domains == NULL)
return TRUE;
if (log_domain == NULL)
{
for (i = 0; i < n_fields; i++)
{
if (g_strcmp0 (fields[i].key, "GLIB_DOMAIN") == 0)
{
log_domain = fields[i].value;
break;
}
}
}
if (strcmp (domains, "all") != 0 &&
(log_domain == NULL || !strstr (domains, log_domain)))
return TRUE;
}
return FALSE;
}
/**
* g_log_writer_default_would_drop:
* @log_domain: (nullable): log domain
* @log_level: log level, either from #GLogLevelFlags, or a user-defined
* level
*
* Check whether g_log_writer_default() and g_log_default_handler() would
* ignore a message with the given domain and level.
*
* As with g_log_default_handler(), this function drops debug and informational
* messages unless their log domain (or `all`) is listed in the space-separated
* `G_MESSAGES_DEBUG` environment variable.
*
* This can be used when implementing log writers with the same filtering
* behaviour as the default, but a different destination or output format:
*
* |[<!-- language="C" -->
* if (g_log_writer_default_would_drop (log_level, log_domain))
* return G_LOG_WRITER_HANDLED;
* ]|
*
* or to skip an expensive computation if it is only needed for a debugging
* message, and `G_MESSAGES_DEBUG` is not set:
*
* |[<!-- language="C" -->
* if (!g_log_writer_default_would_drop (G_LOG_LEVEL_DEBUG, G_LOG_DOMAIN))
* {
* gchar *result = expensive_computation (my_object);
*
* g_debug ("my_object result: %s", result);
* g_free (result);
* }
* ]|
*
* Returns: %TRUE if the log message would be dropped by GLib's
* default log handlers
* Since: 2.68
*/
gboolean
g_log_writer_default_would_drop (GLogLevelFlags log_level,
const char *log_domain)
{
return should_drop_message (log_level, log_domain, NULL, 0);
}
/**
* g_log_writer_default:
* @log_level: log level, either from #GLogLevelFlags, or a user-defined
* level
* @fields: (array length=n_fields): key–value pairs of structured data forming
* the log message
* @n_fields: number of elements in the @fields array
* @user_data: user data passed to g_log_set_writer_func()
*
* Format a structured log message and output it to the default log destination
* for the platform. On Linux, this is typically the systemd journal, falling
* back to `stdout` or `stderr` if running from the terminal or if output is
* being redirected to a file.
*
* Support for other platform-specific logging mechanisms may be added in
* future. Distributors of GLib may modify this function to impose their own
* (documented) platform-specific log writing policies.
*
* This is suitable for use as a #GLogWriterFunc, and is the default writer used
* if no other is set using g_log_set_writer_func().
*
* As with g_log_default_handler(), this function drops debug and informational
* messages unless their log domain (or `all`) is listed in the space-separated
* `G_MESSAGES_DEBUG` environment variable.
*
* g_log_writer_default() uses the mask set by g_log_set_always_fatal() to
* determine which messages are fatal. When using a custom writer func instead it is
* up to the writer function to determine which log messages are fatal.
*
* Returns: %G_LOG_WRITER_HANDLED on success, %G_LOG_WRITER_UNHANDLED otherwise
* Since: 2.50
*/
GLogWriterOutput
g_log_writer_default (GLogLevelFlags log_level,
const GLogField *fields,
gsize n_fields,
gpointer user_data)
{
static gsize initialized = 0;
static gboolean stderr_is_journal = FALSE;
g_return_val_if_fail (fields != NULL, G_LOG_WRITER_UNHANDLED);
g_return_val_if_fail (n_fields > 0, G_LOG_WRITER_UNHANDLED);
if (should_drop_message (log_level, NULL, fields, n_fields))
return G_LOG_WRITER_HANDLED;
/* Mark messages as fatal if they have a level set in
* g_log_set_always_fatal().
*/
if ((log_level & g_log_always_fatal) && !log_is_old_api (fields, n_fields))
log_level |= G_LOG_FLAG_FATAL;
/* Try logging to the systemd journal as first choice. */
if (g_once_init_enter (&initialized))
{
stderr_is_journal = g_log_writer_is_journald (fileno (stderr));
g_once_init_leave (&initialized, TRUE);
}
if (stderr_is_journal &&
g_log_writer_journald (log_level, fields, n_fields, user_data) ==
G_LOG_WRITER_HANDLED)
goto handled;
/* FIXME: Add support for the Windows log. */
if (g_log_writer_standard_streams (log_level, fields, n_fields, user_data) ==
G_LOG_WRITER_HANDLED)
goto handled;
return G_LOG_WRITER_UNHANDLED;
handled:
/* Abort if the message was fatal. */
if (log_level & G_LOG_FLAG_FATAL)
{
/* MessageBox is allowed on UWP apps only when building against
* the debug CRT, which will set -D_DEBUG */
#if defined(G_OS_WIN32) && (defined(_DEBUG) || !defined(G_WINAPI_ONLY_APP))
if (!g_test_initialized ())
{
WCHAR *wide_msg;
wide_msg = g_utf8_to_utf16 (fatal_msg_buf, -1, NULL, NULL, NULL);
MessageBoxW (NULL, wide_msg, NULL, MB_ICONERROR | MB_SETFOREGROUND);
g_free (wide_msg);
}
#endif /* !G_OS_WIN32 */
_g_log_abort (!(log_level & G_LOG_FLAG_RECURSION));
}
return G_LOG_WRITER_HANDLED;
}
static GLogWriterOutput
_g_log_writer_fallback (GLogLevelFlags log_level,
const GLogField *fields,
gsize n_fields,
gpointer user_data)
{
FILE *stream;
gsize i;
/* we cannot call _any_ GLib functions in this fallback handler,
* which is why we skip UTF-8 conversion, etc.
* since we either recursed or ran out of memory, we're in a pretty
* pathologic situation anyways, what we can do is giving the
* the process ID unconditionally however.
*/
stream = log_level_to_file (log_level);
for (i = 0; i < n_fields; i++)
{
const GLogField *field = &fields[i];
/* Only print fields we definitely recognise, otherwise we could end up
* printing a random non-string pointer provided by the user to be
* interpreted by their writer function.
*/
if (strcmp (field->key, "MESSAGE") != 0 &&
strcmp (field->key, "MESSAGE_ID") != 0 &&
strcmp (field->key, "PRIORITY") != 0 &&
strcmp (field->key, "CODE_FILE") != 0 &&
strcmp (field->key, "CODE_LINE") != 0 &&
strcmp (field->key, "CODE_FUNC") != 0 &&
strcmp (field->key, "ERRNO") != 0 &&
strcmp (field->key, "SYSLOG_FACILITY") != 0 &&
strcmp (field->key, "SYSLOG_IDENTIFIER") != 0 &&
strcmp (field->key, "SYSLOG_PID") != 0 &&
strcmp (field->key, "GLIB_DOMAIN") != 0)
continue;
write_string (stream, field->key);
write_string (stream, "=");
write_string_sized (stream, field->value, field->length);
}
#ifndef G_OS_WIN32
{
gchar pid_string[FORMAT_UNSIGNED_BUFSIZE];
format_unsigned (pid_string, getpid (), 10);
write_string (stream, "_PID=");
write_string (stream, pid_string);
}
#endif
return G_LOG_WRITER_HANDLED;
}
/**
* g_return_if_fail_warning: (skip)
* @log_domain: (nullable): log domain
* @pretty_function: function containing the assertion
* @expression: (nullable): expression which failed
*
* Internal function used to print messages from the public g_return_if_fail()
* and g_return_val_if_fail() macros.
*/
void
g_return_if_fail_warning (const char *log_domain,
const char *pretty_function,
const char *expression)
{
g_log (log_domain,
G_LOG_LEVEL_CRITICAL,
"%s: assertion '%s' failed",
pretty_function,
expression);
}
/**
* g_warn_message: (skip)
* @domain: (nullable): log domain
* @file: file containing the warning
* @line: line number of the warning
* @func: function containing the warning
* @warnexpr: (nullable): expression which failed
*
* Internal function used to print messages from the public g_warn_if_reached()
* and g_warn_if_fail() macros.
*/
void
g_warn_message (const char *domain,
const char *file,
int line,
const char *func,
const char *warnexpr)
{
char *s, lstr[32];
g_snprintf (lstr, 32, "%d", line);
if (warnexpr)
s = g_strconcat ("(", file, ":", lstr, "):",
func, func[0] ? ":" : "",
" runtime check failed: (", warnexpr, ")", NULL);
else
s = g_strconcat ("(", file, ":", lstr, "):",
func, func[0] ? ":" : "",
" ", "code should not be reached", NULL);
g_log (domain, G_LOG_LEVEL_WARNING, "%s", s);
g_free (s);
}
void
g_assert_warning (const char *log_domain,
const char *file,
const int line,
const char *pretty_function,
const char *expression)
{
if (expression)
g_log (log_domain,
G_LOG_LEVEL_ERROR,
"file %s: line %d (%s): assertion failed: (%s)",
file,
line,
pretty_function,
expression);
else
g_log (log_domain,
G_LOG_LEVEL_ERROR,
"file %s: line %d (%s): should not be reached",
file,
line,
pretty_function);
_g_log_abort (FALSE);
g_abort ();
}
/**
* g_test_expect_message:
* @log_domain: (nullable): the log domain of the message
* @log_level: the log level of the message
* @pattern: a glob-style [pattern][glib-Glob-style-pattern-matching]
*
* Indicates that a message with the given @log_domain and @log_level,
* with text matching @pattern, is expected to be logged. When this
* message is logged, it will not be printed, and the test case will
* not abort.
*
* This API may only be used with the old logging API (g_log() without
* %G_LOG_USE_STRUCTURED defined). It will not work with the structured logging
* API. See [Testing for Messages][testing-for-messages].
*
* Use g_test_assert_expected_messages() to assert that all
* previously-expected messages have been seen and suppressed.
*
* You can call this multiple times in a row, if multiple messages are
* expected as a result of a single call. (The messages must appear in
* the same order as the calls to g_test_expect_message().)
*
* For example:
*
* |[<!-- language="C" -->
* // g_main_context_push_thread_default() should fail if the
* // context is already owned by another thread.
* g_test_expect_message (G_LOG_DOMAIN,
* G_LOG_LEVEL_CRITICAL,
* "assertion*acquired_context*failed");
* g_main_context_push_thread_default (bad_context);
* g_test_assert_expected_messages ();
* ]|
*
* Note that you cannot use this to test g_error() messages, since
* g_error() intentionally never returns even if the program doesn't
* abort; use g_test_trap_subprocess() in this case.
*
* If messages at %G_LOG_LEVEL_DEBUG are emitted, but not explicitly
* expected via g_test_expect_message() then they will be ignored.
*
* Since: 2.34
*/
void
g_test_expect_message (const gchar *log_domain,
GLogLevelFlags log_level,
const gchar *pattern)
{
GTestExpectedMessage *expected;
g_return_if_fail (log_level != 0);
g_return_if_fail (pattern != NULL);
g_return_if_fail (~log_level & G_LOG_LEVEL_ERROR);
expected = g_new (GTestExpectedMessage, 1);
expected->log_domain = g_strdup (log_domain);
expected->log_level = log_level;
expected->pattern = g_strdup (pattern);
expected_messages = g_slist_append (expected_messages, expected);
}
void
g_test_assert_expected_messages_internal (const char *domain,
const char *file,
int line,
const char *func)
{
if (expected_messages)
{
GTestExpectedMessage *expected;
gchar level_prefix[STRING_BUFFER_SIZE];
gchar *message;
expected = expected_messages->data;
mklevel_prefix (level_prefix, expected->log_level, FALSE);
message = g_strdup_printf ("Did not see expected message %s-%s: %s",
expected->log_domain ? expected->log_domain : "**",
level_prefix, expected->pattern);
g_assertion_message (G_LOG_DOMAIN, file, line, func, message);
g_free (message);
}
}
/**
* g_test_assert_expected_messages:
*
* Asserts that all messages previously indicated via
* g_test_expect_message() have been seen and suppressed.
*
* This API may only be used with the old logging API (g_log() without
* %G_LOG_USE_STRUCTURED defined). It will not work with the structured logging
* API. See [Testing for Messages][testing-for-messages].
*
* If messages at %G_LOG_LEVEL_DEBUG are emitted, but not explicitly
* expected via g_test_expect_message() then they will be ignored.
*
* Since: 2.34
*/
void
_g_log_fallback_handler (const gchar *log_domain,
GLogLevelFlags log_level,
const gchar *message,
gpointer unused_data)
{
gchar level_prefix[STRING_BUFFER_SIZE];
#ifndef G_OS_WIN32
gchar pid_string[FORMAT_UNSIGNED_BUFSIZE];
#endif
FILE *stream;
/* we cannot call _any_ GLib functions in this fallback handler,
* which is why we skip UTF-8 conversion, etc.
* since we either recursed or ran out of memory, we're in a pretty
* pathologic situation anyways, what we can do is giving the
* the process ID unconditionally however.
*/
stream = mklevel_prefix (level_prefix, log_level, FALSE);
if (!message)
message = "(NULL) message";
#ifndef G_OS_WIN32
format_unsigned (pid_string, getpid (), 10);
#endif
if (log_domain)
write_string (stream, "\n");
else
write_string (stream, "\n** ");
#ifndef G_OS_WIN32
write_string (stream, "(process:");
write_string (stream, pid_string);
write_string (stream, "): ");
#endif
if (log_domain)
{
write_string (stream, log_domain);
write_string (stream, "-");
}
write_string (stream, level_prefix);
write_string (stream, ": ");
write_string (stream, message);
}
static void
escape_string (GString *string)
{
const char *p = string->str;
gunichar wc;
while (p < string->str + string->len)
{
gboolean safe;
wc = g_utf8_get_char_validated (p, -1);
if (wc == (gunichar)-1 || wc == (gunichar)-2)
{
gchar *tmp;
guint pos;
pos = p - string->str;
/* Emit invalid UTF-8 as hex escapes
*/
tmp = g_strdup_printf ("\\x%02x", (guint)(guchar)*p);
g_string_erase (string, pos, 1);
g_string_insert (string, pos, tmp);
p = string->str + (pos + 4); /* Skip over escape sequence */
g_free (tmp);
continue;
}
if (wc == '\r')
{
safe = *(p + 1) == '\n';
}
else
{
safe = CHAR_IS_SAFE (wc);
}
if (!safe)
{
gchar *tmp;
guint pos;
pos = p - string->str;
/* Largest char we escape is 0x0a, so we don't have to worry
* about 8-digit \Uxxxxyyyy
*/
tmp = g_strdup_printf ("\\u%04x", wc);
g_string_erase (string, pos, g_utf8_next_char (p) - p);
g_string_insert (string, pos, tmp);
g_free (tmp);
p = string->str + (pos + 6); /* Skip over escape sequence */
}
else
p = g_utf8_next_char (p);
}
}
/**
* g_log_default_handler:
* @log_domain: (nullable): the log domain of the message, or %NULL for the
* default "" application domain
* @log_level: the level of the message
* @message: (nullable): the message
* @unused_data: (nullable): data passed from g_log() which is unused
*
* The default log handler set up by GLib; g_log_set_default_handler()
* allows to install an alternate default log handler.
* This is used if no log handler has been set for the particular log
* domain and log level combination. It outputs the message to stderr
* or stdout and if the log level is fatal it calls G_BREAKPOINT(). It automatically
* prints a new-line character after the message, so one does not need to be
* manually included in @message.
*
* The behavior of this log handler can be influenced by a number of
* environment variables:
*
* - `G_MESSAGES_PREFIXED`: A :-separated list of log levels for which
* messages should be prefixed by the program name and PID of the
* application.
*
* - `G_MESSAGES_DEBUG`: A space-separated list of log domains for
* which debug and informational messages are printed. By default
* these messages are not printed.
*
* stderr is used for levels %G_LOG_LEVEL_ERROR, %G_LOG_LEVEL_CRITICAL,
* %G_LOG_LEVEL_WARNING and %G_LOG_LEVEL_MESSAGE. stdout is used for
* the rest, unless stderr was requested by
* g_log_writer_default_set_use_stderr().
*
* This has no effect if structured logging is enabled; see
* [Using Structured Logging][using-structured-logging].
*/
void
g_log_default_handler (const gchar *log_domain,
GLogLevelFlags log_level,
const gchar *message,
gpointer unused_data)
{
GLogField fields[4];
int n_fields = 0;
/* we can be called externally with recursion for whatever reason */
if (log_level & G_LOG_FLAG_RECURSION)
{
_g_log_fallback_handler (log_domain, log_level, message, unused_data);
return;
}
fields[0].key = "GLIB_OLD_LOG_API";
fields[0].value = "1";
fields[0].length = -1;
n_fields++;
fields[1].key = "MESSAGE";
fields[1].value = message;
fields[1].length = -1;
n_fields++;
fields[2].key = "PRIORITY";
fields[2].value = log_level_to_priority (log_level);
fields[2].length = -1;
n_fields++;
if (log_domain)
{
fields[3].key = "GLIB_DOMAIN";
fields[3].value = log_domain;
fields[3].length = -1;
n_fields++;
}
/* Print out via the structured log API, but drop any fatal flags since we
* have already handled them. The fatal handling in the structured logging
* API is more coarse-grained than in the old g_log() API, so we don't want
* to use it here.
*/
g_log_structured_array (log_level & ~G_LOG_FLAG_FATAL, fields, n_fields);
}
/**
* g_set_print_handler:
* @func: the new print handler
*
* Sets the print handler.
*
* Any messages passed to g_print() will be output via
* the new handler. The default handler simply outputs
* the message to stdout. By providing your own handler
* you can redirect the output, to a GTK+ widget or a
* log file for example.
*
* Returns: the old print handler
*/
GPrintFunc
g_set_print_handler (GPrintFunc func)
{
GPrintFunc old_print_func;
g_mutex_lock (&g_messages_lock);
old_print_func = glib_print_func;
glib_print_func = func;
g_mutex_unlock (&g_messages_lock);
return old_print_func;
}
/**
* g_print:
* @format: the message format. See the printf() documentation
* @...: the parameters to insert into the format string
*
* Outputs a formatted message via the print handler.
* The default print handler simply outputs the message to stdout, without
* appending a trailing new-line character. Typically, @format should end with
* its own new-line character.
*
* g_print() should not be used from within libraries for debugging
* messages, since it may be redirected by applications to special
* purpose message windows or even files. Instead, libraries should
* use g_log(), g_log_structured(), or the convenience macros g_message(),
* g_warning() and g_error().
*/
void
g_print (const gchar *format,
...)
{
va_list args;
gchar *string;
GPrintFunc local_glib_print_func;
g_return_if_fail (format != NULL);
va_start (args, format);
string = g_strdup_vprintf (format, args);
va_end (args);
g_mutex_lock (&g_messages_lock);
local_glib_print_func = glib_print_func;
g_mutex_unlock (&g_messages_lock);
if (local_glib_print_func)
local_glib_print_func (string);
else
{
const gchar *charset;
if (g_get_console_charset (&charset))
fputs (string, stdout); /* charset is UTF-8 already */
else
{
gchar *lstring = strdup_convert (string, charset);
fputs (lstring, stdout);
g_free (lstring);
}
fflush (stdout);
}
g_free (string);
}
/**
* g_set_printerr_handler:
* @func: the new error message handler
*
* Sets the handler for printing error messages.
*
* Any messages passed to g_printerr() will be output via
* the new handler. The default handler simply outputs the
* message to stderr. By providing your own handler you can
* redirect the output, to a GTK+ widget or a log file for
* example.
*
* Returns: the old error message handler
*/
GPrintFunc
g_set_printerr_handler (GPrintFunc func)
{
GPrintFunc old_printerr_func;
g_mutex_lock (&g_messages_lock);
old_printerr_func = glib_printerr_func;
glib_printerr_func = func;
g_mutex_unlock (&g_messages_lock);
return old_printerr_func;
}
/**
* g_printerr:
* @format: the message format. See the printf() documentation
* @...: the parameters to insert into the format string
*
* Outputs a formatted message via the error message handler.
* The default handler simply outputs the message to stderr, without appending
* a trailing new-line character. Typically, @format should end with its own
* new-line character.
*
* g_printerr() should not be used from within libraries.
* Instead g_log() or g_log_structured() should be used, or the convenience
* macros g_message(), g_warning() and g_error().
*/
void
g_printerr (const gchar *format,
...)
{
va_list args;
gchar *string;
GPrintFunc local_glib_printerr_func;
g_return_if_fail (format != NULL);
va_start (args, format);
string = g_strdup_vprintf (format, args);
va_end (args);
g_mutex_lock (&g_messages_lock);
local_glib_printerr_func = glib_printerr_func;
g_mutex_unlock (&g_messages_lock);
if (local_glib_printerr_func)
local_glib_printerr_func (string);
else
{
const gchar *charset;
if (g_get_console_charset (&charset))
fputs (string, stderr); /* charset is UTF-8 already */
else
{
gchar *lstring = strdup_convert (string, charset);
fputs (lstring, stderr);
g_free (lstring);
}
fflush (stderr);
}
g_free (string);
}
/**
* g_printf_string_upper_bound:
* @format: the format string. See the printf() documentation
* @args: the parameters to be inserted into the format string
*
* Calculates the maximum space needed to store the output
* of the sprintf() function.
*
* Returns: the maximum space needed to store the formatted string
*/
gsize
g_printf_string_upper_bound (const gchar *format,
va_list args)
{
gchar c;
return _g_vsnprintf (&c, 1, format, args) + 1;
}