apt-pkg/contrib/configuration.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: configuration.cc,v 1.7 1998/10/20 02:39:26 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 <apt-pkg/error.h>
  20 #include <strutl.h>
  21
  22 #include <stdio.h>
  23 #include <fstream.h>
  24                                                                         /*}}}*/
  25
  26 Configuration *_config = new Configuration;
  27
  28 // Configuration::Configuration - Constructor                           /*{{{*/
  29 // ---------------------------------------------------------------------
  30 /* */
  31 Configuration::Configuration()
  32 {
  33    Root = new Item;
  34 }
  35                                                                         /*}}}*/
  36 // Configuration::Lookup - Lookup a single item                                                                 /*{{{*/
  37 // ---------------------------------------------------------------------
  38 /* This will lookup a single item by name below another item. It is a
  39    helper function for the main lookup function */
  40 Configuration::Item *Configuration::Lookup(Item *Head,const char *S,
  41                                            unsigned long Len,bool Create)
  42 {
  43    int Res = 1;
  44    Item *I = Head->Child;
  45    Item **Last = &Head->Child;
  46    for (; I != 0; Last = &I->Next, I = I->Next)
  47       if ((Res = stringcasecmp(I->Tag.begin(),I->Tag.end(),S,S + Len)) == 0)
  48          break;
  49
  50    if (Res == 0)
  51       return I;
  52    if (Create == false)
  53       return 0;
  54
  55    I = new Item;
  56    I->Tag = string(S,Len);
  57    I->Next = *Last;
  58    I->Parent = Head;
  59    *Last = I;
  60    return I;
  61 }
  62                                                                         /*}}}*/
  63 // Configuration::Lookup - Lookup a fully scoped item                   /*{{{*/
  64 // ---------------------------------------------------------------------
  65 /* This performs a fully scoped lookup of a given name, possibly creating
  66    new items */
  67 Configuration::Item *Configuration::Lookup(const char *Name,bool Create)
  68 {
  69    const char *Start = Name;
  70    const char *End = Start + strlen(Name);
  71    const char *TagEnd = Name;
  72    Item *Itm = Root;
  73    for (; End - TagEnd > 2; TagEnd++)
  74    {
  75       if (TagEnd[0] == ':' && TagEnd[1] == ':')
  76       {
  77          Itm = Lookup(Itm,Start,TagEnd - Start,Create);
  78          if (Itm == 0)
  79             return 0;
  80          TagEnd = Start = TagEnd + 2;
  81       }
  82    }
  83
  84    Itm = Lookup(Itm,Start,End - Start,Create);
  85    return Itm;
  86 }
  87                                                                         /*}}}*/
  88 // Configuration::Find - Find a value                                   /*{{{*/
  89 // ---------------------------------------------------------------------
  90 /* */
  91 string Configuration::Find(const char *Name,const char *Default)
  92 {
  93    Item *Itm = Lookup(Name,false);
  94    if (Itm == 0 || Itm->Value.empty() == true)
  95    {
  96       if (Default == 0)
  97          return string();
  98       else
  99          return Default;
 100    }
 101
 102    return Itm->Value;
 103 }
 104                                                                         /*}}}*/
 105 // Configuration::FindFile - Find a Filename                            /*{{{*/
 106 // ---------------------------------------------------------------------
 107 /* Directories are stored as the base dir in the Parent node and the
 108    sub directory in sub nodes with the final node being the end filename
 109  */
 110 string Configuration::FindFile(const char *Name,const char *Default)
 111 {
 112    Item *Itm = Lookup(Name,false);
 113    if (Itm == 0 || Itm->Value.empty() == true)
 114    {
 115       if (Default == 0)
 116          return string();
 117       else
 118          return Default;
 119    }
 120
 121    // Absolute path
 122    if (Itm->Value[0] == '/' || Itm->Parent == 0)
 123       return Itm->Value;
 124
 125    // ./ is also considered absolute as is anything with ~ in it
 126    if (Itm->Value[0] != 0 &&
 127        ((Itm->Value[0] == '.' && Itm->Value[1] == '/') ||
 128         (Itm->Value[0] == '~' && Itm->Value[1] == '/')))
 129       return Itm->Value;
 130
 131    if (Itm->Parent->Value.end()[-1] == '/')
 132       return Itm->Parent->Value + Itm->Value;
 133    else
 134       return Itm->Parent->Value + '/' + Itm->Value;
 135 }
 136                                                                         /*}}}*/
 137 // Configuration::FindDir - Find a directory name                       /*{{{*/
 138 // ---------------------------------------------------------------------
 139 /* This is like findfile execept the result is terminated in a / */
 140 string Configuration::FindDir(const char *Name,const char *Default)
 141 {
 142    string Res = FindFile(Name,Default);
 143    if (Res.end()[-1] != '/')
 144       return Res + '/';
 145    return Res;
 146 }
 147                                                                         /*}}}*/
 148 // Configuration::FindI - Find an integer value                         /*{{{*/
 149 // ---------------------------------------------------------------------
 150 /* */
 151 int Configuration::FindI(const char *Name,int Default)
 152 {
 153    Item *Itm = Lookup(Name,false);
 154    if (Itm == 0 || Itm->Value.empty() == true)
 155       return Default;
 156
 157    char *End;
 158    int Res = strtol(Itm->Value.c_str(),&End,0);
 159    if (End == Itm->Value.c_str())
 160       return Default;
 161
 162    return Res;
 163 }
 164                                                                         /*}}}*/
 165 // Configuration::FindB - Find a boolean type                           /*{{{*/
 166 // ---------------------------------------------------------------------
 167 /* */
 168 bool Configuration::FindB(const char *Name,bool Default)
 169 {
 170    Item *Itm = Lookup(Name,false);
 171    if (Itm == 0 || Itm->Value.empty() == true)
 172       return Default;
 173
 174    return StringToBool(Itm->Value,Default);
 175 }
 176                                                                         /*}}}*/
 177 // Configuration::Set - Set a value                                     /*{{{*/
 178 // ---------------------------------------------------------------------
 179 /* */
 180 void Configuration::Set(const char *Name,string Value)
 181 {
 182    Item *Itm = Lookup(Name,true);
 183    if (Itm == 0)
 184       return;
 185    Itm->Value = Value;
 186 }
 187                                                                         /*}}}*/
 188 // Configuration::Set - Set an integer value                            /*{{{*/
 189 // ---------------------------------------------------------------------
 190 /* */
 191 void Configuration::Set(const char *Name,int Value)
 192 {
 193    Item *Itm = Lookup(Name,true);
 194    if (Itm == 0)
 195       return;
 196    char S[300];
 197    snprintf(S,sizeof(S),"%i",Value);
 198    Itm->Value = S;
 199 }
 200                                                                         /*}}}*/
 201 // Configuration::Exists - Returns true if the Name exists              /*{{{*/
 202 // ---------------------------------------------------------------------
 203 /* */
 204 bool Configuration::Exists(const char *Name)
 205 {
 206    Item *Itm = Lookup(Name,false);
 207    if (Itm == 0)
 208       return false;
 209    return true;
 210 }
 211                                                                         /*}}}*/
 212
 213 // ReadConfigFile - Read a configuration file                           /*{{{*/
 214 // ---------------------------------------------------------------------
 215 /* The configuration format is very much like the named.conf format
 216    used in bind8, in fact this routine can parse most named.conf files. */
 217 bool ReadConfigFile(Configuration &Conf,string FName)
 218 {
 219    // Open the stream for reading
 220    ifstream F(FName.c_str(),ios::in | ios::nocreate);
 221    if (!F != 0)
 222       return _error->Errno("ifstream::ifstream","Opening configuration file %s",FName.c_str());
 223
 224    char Buffer[300];
 225    string LineBuffer;
 226
 227    // Parser state
 228    string ParentTag;
 229
 230    int CurLine = 0;
 231    bool InComment = false;
 232    while (F.eof() == false)
 233    {
 234       F.getline(Buffer,sizeof(Buffer));
 235       CurLine++;
 236       _strtabexpand(Buffer,sizeof(Buffer));
 237       _strstrip(Buffer);
 238
 239       // Multi line comment
 240       if (InComment == true)
 241       {
 242          for (const char *I = Buffer; *I != 0; I++)
 243          {
 244             if (*I == '*' && I[1] == '/')
 245             {
 246                memmove(Buffer,I+2,strlen(I+2) + 1);
 247                InComment = false;
 248                break;
 249             }
 250          }
 251          if (InComment == true)
 252             continue;
 253       }
 254
 255       // Discard single line comments
 256       for (char *I = Buffer; *I != 0; I++)
 257       {
 258          if (*I == '/' && I[1] == '/')
 259          {
 260             *I = 0;
 261             break;
 262          }
 263       }
 264
 265       // Look for multi line comments
 266       for (char *I = Buffer; *I != 0; I++)
 267       {
 268          if (*I == '/' && I[1] == '*')
 269          {
 270             InComment = true;
 271             for (char *J = Buffer; *J != 0; J++)
 272             {
 273                if (*J == '*' && J[1] == '/')
 274                {
 275                   memmove(I,J+2,strlen(J+2) + 1);
 276                   InComment = false;
 277                   break;
 278                }
 279             }
 280
 281             if (InComment == true)
 282             {
 283                *I = 0;
 284                break;
 285             }
 286          }
 287       }
 288
 289       // Blank
 290       if (Buffer[0] == 0)
 291          continue;
 292
 293       // We now have a valid line fragment
 294       for (char *I = Buffer; *I != 0;)
 295       {
 296          if (*I == '{' || *I == ';' || *I == '}')
 297          {
 298             // Put the last fragement into the buffer
 299             char *Start = Buffer;
 300             char *Stop = I;
 301             for (; Start != I && isspace(*Start) != 0; Start++);
 302             for (; Stop != Start && isspace(Stop[-1]) != 0; Stop--);
 303             if (LineBuffer.empty() == false && Stop - Start != 0)
 304                LineBuffer += ' ';
 305             LineBuffer += string(Start,Stop - Start);
 306
 307             // Remove the fragment
 308             char TermChar = *I;
 309             memmove(Buffer,I + 1,strlen(I + 1) + 1);
 310             I = Buffer;
 311
 312             // Move up a tag
 313             if (TermChar == '}')
 314             {
 315                string::size_type Pos = ParentTag.rfind("::");
 316                if (Pos == string::npos)
 317                   ParentTag = string();
 318                else
 319                   ParentTag = string(ParentTag,0,Pos);
 320             }
 321
 322             // Syntax Error
 323             if (TermChar == '{' && LineBuffer.empty() == true)
 324                return _error->Error("Syntax error %s:%u: Block starts with no name.",FName.c_str(),CurLine);
 325
 326             if (LineBuffer.empty() == true)
 327                continue;
 328
 329             // Parse off the tag
 330             string::size_type Pos = LineBuffer.find(' ');
 331             if (Pos == string::npos)
 332             {
 333                if (TermChar == '{')
 334                   Pos = LineBuffer.length();
 335                else
 336                   return _error->Error("Syntax error %s:%u: Tag with no value",FName.c_str(),CurLine);
 337             }
 338
 339             string Tag = string(LineBuffer,0,Pos);
 340
 341             // Go down a level
 342             if (TermChar == '{')
 343             {
 344                if (ParentTag.empty() == true)
 345                   ParentTag = Tag;
 346                else
 347                   ParentTag += string("::") + Tag;
 348                Tag = string();
 349             }
 350
 351             // We dont have a value to set
 352             if (Pos == LineBuffer.length())
 353             {
 354                LineBuffer = string();
 355                continue;
 356             }
 357
 358             // Parse off the word
 359             string Word;
 360             if (ParseCWord(LineBuffer.c_str()+Pos,Word) == false)
 361                return _error->Error("Syntax error %s:%u: Malformed value",FName.c_str(),CurLine);
 362
 363             // Generate the item name
 364             string Item;
 365             if (ParentTag.empty() == true)
 366                Item = Tag;
 367             else
 368             {
 369                if (Tag.empty() == true)
 370                   Item = ParentTag;
 371                else
 372                   Item = ParentTag + "::" + Tag;
 373             }
 374
 375             // Set the item in the configuration class
 376             Conf.Set(Item,Word);
 377
 378             // Empty the buffer
 379             LineBuffer = string();
 380          }
 381          else
 382             I++;
 383       }
 384
 385       // Store the fragment
 386       const char *Stripd = _strstrip(Buffer);
 387       if (*Stripd != 0 && LineBuffer.empty() == false)
 388          LineBuffer += " ";
 389       LineBuffer += Stripd;
 390    }
 391
 392    return true;
 393 }
 394                                                                         /*}}}*/