libgeda/src/s_log.c

   1 /* gEDA - GPL Electronic Design Automation
   2  * libgeda - gEDA's library
   3  * Copyright (C) 1998-2007 Ales Hvezda
   4  * Copyright (C) 1998-2007 gEDA Contributors (see ChangeLog for details)
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111 USA
  19  */
  20 #include <config.h>
  21
  22 #include <stdio.h>
  23 #include <sys/stat.h>
  24 #ifdef HAVE_STDLIB_H
  25 #include <stdlib.h>
  26 #endif
  27 #ifdef HAVE_ASSERT_H
  28 #include <assert.h>
  29 #endif
  30 #ifdef HAVE_UNISTD_H
  31 #include <unistd.h>
  32 #endif
  33 #ifdef HAVE_STDARG_H
  34 #include <stdarg.h>
  35 #endif
  36 #ifdef HAVE_FCNTL_H
  37 #include <fcntl.h>
  38 #endif
  39 #ifdef HAVE_ERRNO_H
  40 #include <errno.h>
  41 #endif
  42 #ifdef HAVE_STRING_H
  43 #include <string.h>
  44 #endif
  45
  46 #include <gtk/gtk.h>
  47 #include <libguile.h>
  48
  49 #include "defines.h"
  50 #include "struct.h"
  51 #include "defines.h"
  52 #include "globals.h"
  53 #include "funcs.h"
  54 #include "o_types.h"
  55
  56 #include "../include/prototype.h"
  57
  58 #ifdef HAVE_LIBDMALLOC
  59 #include <dmalloc.h>
  60 #endif
  61
  62
  63 static void s_log_handler (const gchar *log_domain,
  64                            GLogLevelFlags log_level,
  65                            const gchar *message,
  66                            gpointer user_data);
  67
  68 static int logfile_fd = -1;
  69
  70 static guint log_handler_id;
  71
  72 /*! \brief Initialize libgeda logging feature.
  73  *  \par Function Description
  74  *  This function opens the file <B>filename</B> to log to and registers the
  75  *  handler to redirect log message to this file.
  76  *
  77  *  \param [in] filename  Character string with file name to log to.
  78  */
  79 void s_log_init (const gchar *filename)
  80 {
  81   if (do_logging == FALSE) {
  82     logfile_fd = -1;
  83     return;
  84   }
  85
  86   /* create log file */
  87   logfile_fd = open (filename, O_RDWR|O_CREAT|O_TRUNC, 0600);
  88   if (logfile_fd == -1) {
  89     fprintf(stderr, "Could not open log file: %s\n", filename);
  90     fprintf(stderr, "Errno was: %d\n", errno);
  91     return;
  92   }
  93
  94   /* install the log handler */
  95   log_handler_id = g_log_set_handler (NULL,
  96                                       G_LOG_LEVEL_MESSAGE,
  97                                       s_log_handler,
  98                                       NULL);
  99
 100 }
 101
 102 /*! \brief Terminates the logging of messages.
 103  *  \par Function Description
 104  *  This function deregisters the handler for redirection to the log file
 105  *  and closes it.
 106  */
 107 void s_log_close (void)
 108 {
 109   do_logging = FALSE; /* subsequent messages are lost after the close */
 110
 111   if (logfile_fd == -1)
 112   {
 113     return;
 114   }
 115
 116   /* remove the handler */
 117   g_log_remove_handler (NULL, log_handler_id);
 118
 119   /* close the file */
 120   if (logfile_fd != -1) {
 121     close (logfile_fd);
 122     logfile_fd = -1;
 123   }
 124
 125 }
 126
 127 /*! \brief  Reads the current log file and returns its contents.
 128  *  \par Function Description
 129  *  This function reads the current log file and returns its contents.
 130  *
 131  *  \return Character string with current log's contents.
 132  *
 133  */
 134 gchar *s_log_read (void)
 135 {
 136   gboolean tmp;
 137 #define BUFSIZE 200
 138   gchar buf[BUFSIZE];
 139   GString *contents;
 140   gint len;
 141
 142   if (logfile_fd == -1) {
 143     return NULL;
 144   }
 145
 146   tmp = do_logging;
 147   do_logging = FALSE;
 148
 149   /* rewind the file */
 150   lseek(logfile_fd, 0, SEEK_SET);
 151
 152   /* read its contents and build a string */
 153   contents = g_string_new ("");
 154   while ((len = read (logfile_fd, &buf, BUFSIZE)) != 0) {
 155     contents = g_string_append_len (contents, buf, len);
 156   }
 157
 158   do_logging = tmp;
 159
 160   return g_string_free (contents, FALSE);
 161 }
 162
 163 /*! \brief Write a message to the current log file.
 164  *  \par Function Description
 165  *  Writes <B>message</B> to the current log file whose file descriptor
 166  *  is <B>logfile_fd</B>.
 167  *
 168  *  It also sends <B>message</B> to the optional function <B>x_log_update</B>
 169  *  for further use.
 170  *
 171  *  \param [in] log_domain  (unused).
 172  *  \param [in] log_level   (unused).
 173  *  \param [in] message     Character string containing message to
 174  *                          write to log.
 175  *  \param [in] user_data   (unused).
 176  *
 177  */
 178 static void s_log_handler (const gchar *log_domain,
 179                            GLogLevelFlags log_level,
 180                            const gchar *message,
 181                            gpointer user_data)
 182 {
 183   int status;
 184
 185   if (do_logging == FALSE) {
 186     return;
 187   }
 188   g_assert (logfile_fd != -1);
 189
 190   status = write (logfile_fd, message, strlen (message));
 191   if (status == -1) {
 192     fprintf(stderr, "Could not write message to log file\n");
 193     fprintf(stderr, "Message was: %s\n", message);
 194     fprintf(stderr, "Errno was: %d\n", errno);
 195   }
 196
 197   if (x_log_update_func) {
 198     (*x_log_update_func) (message);
 199   }
 200
 201 }