xapian-applications/omega/configfile.cc

   1 /** @file
   2  * @brief Read a config file for omega.
   3  */
   4 /* Copyright 2001 Lemur Consulting Ltd.
   5  * Copyright 2002 Ananova Ltd
   6  * Copyright 2003,2005,2007,2010,2015 Olly Betts
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of the
  11  * License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
  21  * USA
  22  */
  23
  24 #include <config.h>
  25
  26 #include <fstream>
  27
  28 #include <sys/types.h>
  29 #include "safesysstat.h"
  30 #include "safeunistd.h"
  31 #include <cstdlib>
  32 #include "stringutils.h"
  33
  34 #include "configfile.h"
  35
  36 using namespace std;
  37
  38 static const char configfile_local[] = "omega.conf";
  39 static const char configfile_system[] = CONFIGFILE_SYSTEM;
  40 static const char configfile_envvar[] = "OMEGA_CONFIG_FILE";
  41
  42 string database_dir = "/var/lib/omega/data/";
  43 string template_dir = "/var/lib/omega/templates/";
  44 string default_template = "query";
  45 string default_db = "default";
  46 string log_dir = "/var/log/omega/";
  47 string cdb_dir = "/var/lib/omega/cdb/";
  48
  49 /** Return true if the file fname exists.
  50  */
  51 static bool
  52 file_exists(const char * fname)
  53 {
  54     struct stat sbuf;
  55     // exists && is a regular file or symlink
  56     return stat(fname, &sbuf) >= 0 && !S_ISDIR(sbuf.st_mode);
  57 }
  58
  59 static bool
  60 try_read_config_file(const char * cfile)
  61 {
  62     ifstream in(cfile);
  63     if (!in) {
  64         if (file_exists(cfile))
  65             throw string("Can't open configuration file '") + cfile + "'";
  66         return false;
  67     }
  68
  69     while (in) {
  70         char line[1024];
  71         in.getline(line, sizeof(line));
  72
  73         char *p = line;
  74         while (C_isspace(*p)) ++p;
  75         if (!*p || *p == '#') continue; // Ignore blank line and comments
  76
  77         char *q = p;
  78         while (*q && !C_isspace(*q)) ++q;
  79         string name(p, q - p);
  80
  81         p = q;
  82         while (C_isspace(*p)) ++p;
  83         q = p;
  84         while (*q && !C_isspace(*q)) ++q;
  85         string value(p, q - p);
  86
  87         while (*q && C_isspace(*q)) ++q;
  88         if (value.empty() || *q) {
  89             throw string("Bad line in configuration file '") + cfile + "'";
  90         }
  91
  92         if (endswith(name, "_dir") && *value.rbegin() != '/')
  93             value += '/';
  94
  95         if (name == "database_dir") {
  96             swap(database_dir, value);
  97         } else if (name == "template_dir") {
  98             swap(template_dir, value);
  99         } else if (name == "default_template") {
 100             swap(default_template, value);
 101         } else if (name == "default_db") {
 102             swap(default_db, value);
 103         } else if (name == "log_dir") {
 104             swap(log_dir, value);
 105         } else if (name == "cdb_dir") {
 106             swap(cdb_dir, value);
 107         }
 108     }
 109
 110     return true;
 111 }
 112
 113 void
 114 read_config_file()
 115 {
 116     // Tries to find the config file in various ways.  If a config file
 117     // is found in a particular location but is not readable, an error
 118     // is thrown.  If a config file isn't found in a particular location,
 119     // the next candidate is tried.
 120
 121     // First check if a location is specified in the environment variable.
 122     const char * cfile = getenv(configfile_envvar);
 123     if (cfile != NULL && cfile[0] != '\0') {
 124         if (try_read_config_file(cfile)) return;
 125     }
 126
 127     // Next, try reading the local config file.
 128     if (try_read_config_file(configfile_local)) return;
 129
 130     // Finally read the system config file.
 131     if (try_read_config_file(configfile_system)) return;
 132
 133     // Just use the default configuration.
 134     return;
 135 }