apt-pkg/contrib/configuration.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: configuration.cc,v 1.3 1998/07/12 23:58:44 jgg Exp $
   4 /* ######################################################################
   5
   6    Configuration Class
   7
   8    This class provides a configuration file and command line parser
   9    for a tree-oriented configuration environment. All runtime configuration
  10    is stored in here.
  11
  12    ##################################################################### */
  13                                                                         /*}}}*/
  14 // Include files                                                        /*{{{*/
  15 #ifdef __GNUG__
  16 #pragma implementation "apt-pkg/configuration.h"
  17 #endif
  18 #include <apt-pkg/configuration.h>
  19 #include <strutl.h>
  20
  21 #include <stdio.h>
  22                                                                         /*}}}*/
  23
  24 Configuration *_config = new Configuration;
  25
  26 // Configuration::Configuration - Constructor                           /*{{{*/
  27 // ---------------------------------------------------------------------
  28 /* */
  29 Configuration::Configuration()
  30 {
  31    Root = new Item;
  32 }
  33                                                                         /*}}}*/
  34 // Configuration::Lookup - Lookup a single item                                                                 /*{{{*/
  35 // ---------------------------------------------------------------------
  36 /* This will lookup a single item by name below another item. It is a
  37    helper function for the main lookup function */
  38 Configuration::Item *Configuration::Lookup(Item *Head,const char *S,
  39                                            unsigned long Len,bool Create)
  40 {
  41    int Res = 1;
  42    Item *I = Head->Child;
  43    Item **Last = &Head->Child;
  44    for (; I != 0; Last = &I->Next, I = I->Next)
  45       if ((Res = stringcasecmp(I->Tag.begin(),I->Tag.end(),S,S + Len)) == 0)
  46          break;
  47
  48    if (Res == 0)
  49       return I;
  50    if (Create == false)
  51       return 0;
  52
  53    I = new Item;
  54    I->Tag = string(S,Len);
  55    I->Next = *Last;
  56    I->Parent = Head;
  57    *Last = I;
  58    return I;
  59 }
  60                                                                         /*}}}*/
  61 // Configuration::Lookup - Lookup a fully scoped item                   /*{{{*/
  62 // ---------------------------------------------------------------------
  63 /* This performs a fully scoped lookup of a given name, possibly creating
  64    new items */
  65 Configuration::Item *Configuration::Lookup(const char *Name,bool Create)
  66 {
  67    const char *Start = Name;
  68    const char *End = Start + strlen(Name);
  69    const char *TagEnd = Name;
  70    Item *Itm = Root;
  71    for (; End - TagEnd > 2; TagEnd++)
  72    {
  73       if (TagEnd[0] == ':' && TagEnd[1] == ':')
  74       {
  75          Itm = Lookup(Itm,Start,TagEnd - Start,Create);
  76          if (Itm == 0)
  77             return 0;
  78          TagEnd = Start = TagEnd + 2;
  79       }
  80    }
  81
  82    Itm = Lookup(Itm,Start,End - Start,Create);
  83    return Itm;
  84 }
  85                                                                         /*}}}*/
  86 // Configuration::Find - Find a value                                   /*{{{*/
  87 // ---------------------------------------------------------------------
  88 /* */
  89 string Configuration::Find(const char *Name,const char *Default)
  90 {
  91    Item *Itm = Lookup(Name,false);
  92    if (Itm == 0 || Itm->Value.empty() == true)
  93    {
  94       if (Default == 0)
  95          return string();
  96       else
  97          return Default;
  98    }
  99
 100    return Itm->Value;
 101 }
 102                                                                         /*}}}*/
 103 // Configuration::FindDir - Find a directory                            /*{{{*/
 104 // ---------------------------------------------------------------------
 105 /* Directories are stored as the base dir in the Parent node and the
 106  */
 107 string Configuration::FindDir(const char *Name,const char *Default = 0)
 108 {
 109    Item *Itm = Lookup(Name,false);
 110    if (Itm == 0 || Itm->Value.empty() == true)
 111    {
 112       if (Default == 0)
 113          return string();
 114       else
 115          return Default;
 116    }
 117
 118    if (Itm->Value[0] == '/' || Itm->Parent == 0)
 119       return Itm->Value;
 120    if (Itm->Parent->Value.end()[-1] == '/')
 121       return Itm->Parent->Value + Itm->Value;
 122    else
 123       return Itm->Parent->Value + '/' + Itm->Value;
 124 }
 125                                                                         /*}}}*/
 126 // Configuration::FindI - Find an integer value                         /*{{{*/
 127 // ---------------------------------------------------------------------
 128 /* */
 129 int Configuration::FindI(const char *Name,int Default)
 130 {
 131    Item *Itm = Lookup(Name,false);
 132    if (Itm == 0 || Itm->Value.empty() == true)
 133       return Default;
 134
 135    char *End;
 136    int Res = strtol(Itm->Value.c_str(),&End,0);
 137    if (End == Itm->Value.c_str())
 138       return Default;
 139
 140    return Res;
 141 }
 142                                                                         /*}}}*/
 143 // Configuration::Set - Set a value                                     /*{{{*/
 144 // ---------------------------------------------------------------------
 145 /* */
 146 void Configuration::Set(const char *Name,string Value)
 147 {
 148    Item *Itm = Lookup(Name,true);
 149    if (Itm == 0)
 150       return;
 151    Itm->Value = Value;
 152 }
 153                                                                         /*}}}*/
 154 // Configuration::Set - Set an integer value                            /*{{{*/
 155 // ---------------------------------------------------------------------
 156 /* */
 157 void Configuration::Set(const char *Name,int Value)
 158 {
 159    Item *Itm = Lookup(Name,true);
 160    if (Itm == 0)
 161       return;
 162    char S[300];
 163    snprintf(S,sizeof(S),"%i",Value);
 164    Itm->Value = S;
 165 }
 166                                                                         /*}}}*/