apt-pkg/contrib/configuration.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: configuration.cc,v 1.1 1998/07/07 04:17:10 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 "pkglib/configuration.h"
  17 #endif
  18 #include <pkglib/configuration.h>
  19 #include <strutl.h>
  20
  21 #include <stdio.h>
  22                                                                         /*}}}*/
  23 Configuration *_config;
  24
  25 // Configuration::Configuration - Constructor                           /*{{{*/
  26 // ---------------------------------------------------------------------
  27 /* */
  28 Configuration::Configuration()
  29 {
  30    Root = new Item;
  31 }
  32                                                                         /*}}}*/
  33 // Configuration::Lookup - Lookup a single item                                                                 /*{{{*/
  34 // ---------------------------------------------------------------------
  35 /* This will lookup a single item by name below another item. It is a
  36    helper function for the main lookup function */
  37 Configuration::Item *Configuration::Lookup(Item *Head,const char *S,
  38                                            unsigned long Len,bool Create)
  39 {
  40    int Res = 1;
  41    Item *I = Head->Child;
  42    Item **Last = &Head->Child;
  43    for (; I != 0; Last = &I->Next, I = I->Next)
  44       if ((Res = stringcasecmp(I->Value.begin(),I->Value.end(),S,S + Len)) == 0)
  45          break;
  46
  47    if (Res == 0)
  48       return I;
  49    if (Create == false)
  50       return 0;
  51
  52    I = new Item;
  53    I->Value = string(S,Len);
  54    I->Next = *Last;
  55    *Last = I;
  56    return I;
  57 }
  58                                                                         /*}}}*/
  59 // Configuration::Lookup - Lookup a fully scoped item                   /*{{{*/
  60 // ---------------------------------------------------------------------
  61 /* This performs a fully scoped lookup of a given name, possibly creating
  62    new items */
  63 Configuration::Item *Configuration::Lookup(const char *Name,bool Create)
  64 {
  65    const char *Start = Name;
  66    const char *End = Start + strlen(Name);
  67    const char *TagEnd = Name;
  68    Item *Itm = Root;
  69    for (; End - TagEnd > 2; TagEnd++)
  70    {
  71       if (TagEnd[0] == ':' && TagEnd[1] == ':')
  72       {
  73          Itm = Lookup(Itm,Start,TagEnd - Start,Create);
  74          if (Itm == 0)
  75             return 0;
  76          TagEnd = Start = TagEnd + 2;
  77       }
  78    }
  79
  80    Itm = Lookup(Itm,Start,End - Start,Create);
  81    if (Itm == 0)
  82       return 0;
  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       return Default;
  94    return Itm->Value;
  95 }
  96                                                                         /*}}}*/
  97 // Configuration::FindI - Find an integer value                         /*{{{*/
  98 // ---------------------------------------------------------------------
  99 /* */
 100 int Configuration::FindI(const char *Name,int Default)
 101 {
 102    Item *Itm = Lookup(Name,false);
 103    if (Itm == 0 || Itm->Value.empty() == true)
 104       return Default;
 105
 106    char *End;
 107    int Res = strtol(Itm->Value.c_str(),&End,0);
 108    if (End == Itm->Value.c_str())
 109       return Default;
 110
 111    return Res;
 112 }
 113                                                                         /*}}}*/
 114 // Configuration::Set - Set a value                                     /*{{{*/
 115 // ---------------------------------------------------------------------
 116 /* */
 117 void Configuration::Set(const char *Name,string Value)
 118 {
 119    Item *Itm = Lookup(Name,true);
 120    if (Itm == 0)
 121       return;
 122    Itm->Value = Value;
 123 }
 124                                                                         /*}}}*/
 125 // Configuration::Set - Set an integer value                            /*{{{*/
 126 // ---------------------------------------------------------------------
 127 /* */
 128 void Configuration::Set(const char *Name,int Value)
 129 {
 130    Item *Itm = Lookup(Name,true);
 131    if (Itm == 0)
 132       return;
 133    char S[300];
 134    snprintf(S,sizeof(S),"%i",Value);
 135    Itm->Value = S;
 136 }
 137                                                                         /*}}}*/