cpp/example_cpp_custom_severity_levels/example_cpp_custom_severity_levels.cpp

Demonstrates how to implement a custom back-end with custom severity levels to provide tabbed output.

/* /////////////////////////////////////////////////////////////////////////////
 * File:        examples/cpp/example_cpp_custom_severity_levels/example_cpp_custom_severity_levels.cpp
 *
 * Purpose:     C++ example program for Pantheios. Demonstrates:
 *
 *                - use of custom severity level information for tabbing output
 *                - definition of a custom back-end that supports tabbed output
 *                - use of pantheios::puts() in bail-out conditions
 *
 * Created:     31st August 2006
 * Updated:     2nd September 2006
 *
 * www:         http://www.pantheios.org/
 *
 * License:     This source code is placed into the public domain 2006
 *              by Synesis Software Pty Ltd. There are no restrictions
 *              whatsoever to your use of the software.
 *
 *              This software is provided "as is", and any warranties,
 *              express or implied, of any kind and for any purpose, are
 *              disclaimed.
 *
 * ////////////////////////////////////////////////////////////////////////// */


/* Pantheios Header Files */
#include <pantheios/pantheios.hpp>          // Pantheios C++ main header
#include <pantheios/backend.h>

/* STLSoft Header Files */
#include <stlsoft/memory/auto_buffer.hpp>   // for stlsoft::auto_buffer

/* Standard C/C++ Header Files */
#include <exception>                        // for std::exception
#include <string>                           // for std::string
#include <stdio.h>                          // for fprintf()
#include <stdlib.h>                         // for exit codes
#include <string.h>                         // for strdup()

#ifndef PANTHEIOS_DOCUMENTATION_SKIP_SECTION
# if defined(STLSOFT_COMPILER_IS_MSVC)
#  pragma warning(disable : 4702)
# endif /* compiler */
#endif /* !PANTHEIOS_DOCUMENTATION_SKIP_SECTION */

/* ////////////////////////////////////////////////////////////////////////// */

// Define the fe.simple process identity, so that it links when using fe.simple
PANTHEIOS_EXTERN_C const char   FE_SIMPLE_PROCESS_IDENTITY[]    =   "example_cpp_custom_severity_levels";

/* ////////////////////////////////////////////////////////////////////////// */

int main()
{
  try
  {
    // Logging at standard "notice" level; Output: "Hello"

    pantheios::log(pantheios::notice, "Hello");

    // Logging at standard "notice" level, with additional severity level
    // information; Output: "  Hello"

    pantheios::log(pantheios::notice(2), "Hello");


    return EXIT_SUCCESS;
  }
  catch(std::bad_alloc &)
  {
    pantheios::log_CRITICAL("out of memory");
  }
  catch(std::exception &x)
  {
    pantheios::log_ALERT("Exception: ", x);
  }
  catch(...)
  {
    pantheios::puts(pantheios::emergency, "Unexpected unknown error");
  }

  return EXIT_FAILURE;
}

/* ////////////////////////////////////////////////////////////////////////// */

PANTHEIOS_CALL(int) pantheios_be_init(  char const  *processIdentity
                                    ,   void        * /* reserved */
                                    ,   void        **ptoken)
{
  *ptoken = ::strdup(processIdentity);

  return (NULL == *ptoken) ? -2 : 0;
}

PANTHEIOS_CALL(void) pantheios_be_uninit(void *token)
{
  ::free(token);
}

PANTHEIOS_CALL(int) pantheios_be_logEntry(  void        * /* feToken */
                                        ,   void        *beToken
                                        ,   int         severity
                                        ,   char const  *entry
                                        ,   size_t      cchEntry)
{
  int     severityLevel   =   severity & 0x07;
  int     customInfo24    =   severity >> 8;

  try
  {
    stlsoft::auto_buffer<char, 256> prefixes(static_cast<size_t>(customInfo24));
    char const                      *severity   = pantheios::getSeverityString(severityLevel);
    FILE                            *stm        = (severityLevel < pantheios::notice) ? stderr : stdout;
    char const                      *processId  = static_cast<char const*>(beToken);

    memset(&prefixes[0], ' ', prefixes.size());

    return ::fprintf( stm
                    , "[%s; %s]:%.*s %.*s\n"
                    , processId, severity
                    , int(prefixes.size()), prefixes.data()
                    , int(cchEntry), entry);
  }
  catch(std::exception &)
  {
    return 0;
  }
}

/* ////////////////////////////////////////////////////////////////////////// */

pantheios Library documentation © Matthew Wilson, 2006