apt-pkg/contrib/configuration.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: configuration.cc,v 1.8 1998/10/22 04:56:45 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    if (Name == 0)
  70       return Root->Child;
  71
  72    const char *Start = Name;
  73    const char *End = Start + strlen(Name);
  74    const char *TagEnd = Name;
  75    Item *Itm = Root;
  76    for (; End - TagEnd > 2; TagEnd++)
  77    {
  78       if (TagEnd[0] == ':' && TagEnd[1] == ':')
  79       {
  80          Itm = Lookup(Itm,Start,TagEnd - Start,Create);
  81          if (Itm == 0)
  82             return 0;
  83          TagEnd = Start = TagEnd + 2;
  84       }
  85    }
  86
  87    Itm = Lookup(Itm,Start,End - Start,Create);
  88    return Itm;
  89 }
  90                                                                         /*}}}*/
  91 // Configuration::Find - Find a value                                   /*{{{*/
  92 // ---------------------------------------------------------------------
  93 /* */
  94 string Configuration::Find(const char *Name,const char *Default)
  95 {
  96    Item *Itm = Lookup(Name,false);
  97    if (Itm == 0 || Itm->Value.empty() == true)
  98    {
  99       if (Default == 0)
 100          return string();
 101       else
 102          return Default;
 103    }
 104
 105    return Itm->Value;
 106 }
 107                                                                         /*}}}*/
 108 // Configuration::FindFile - Find a Filename                            /*{{{*/
 109 // ---------------------------------------------------------------------
 110 /* Directories are stored as the base dir in the Parent node and the
 111    sub directory in sub nodes with the final node being the end filename
 112  */
 113 string Configuration::FindFile(const char *Name,const char *Default)
 114 {
 115    Item *Itm = Lookup(Name,false);
 116    if (Itm == 0 || Itm->Value.empty() == true)
 117    {
 118       if (Default == 0)
 119          return string();
 120       else
 121          return Default;
 122    }
 123
 124    // Absolute path
 125    if (Itm->Value[0] == '/' || Itm->Parent == 0)
 126       return Itm->Value;
 127
 128    // ./ is also considered absolute as is anything with ~ in it
 129    if (Itm->Value[0] != 0 &&
 130        ((Itm->Value[0] == '.' && Itm->Value[1] == '/') ||
 131         (Itm->Value[0] == '~' && Itm->Value[1] == '/')))
 132       return Itm->Value;
 133
 134    if (Itm->Parent->Value.end()[-1] == '/')
 135       return Itm->Parent->Value + Itm->Value;
 136    else
 137       return Itm->Parent->Value + '/' + Itm->Value;
 138 }
 139                                                                         /*}}}*/
 140 // Configuration::FindDir - Find a directory name                       /*{{{*/
 141 // ---------------------------------------------------------------------
 142 /* This is like findfile execept the result is terminated in a / */
 143 string Configuration::FindDir(const char *Name,const char *Default)
 144 {
 145    string Res = FindFile(Name,Default);
 146    if (Res.end()[-1] != '/')
 147       return Res + '/';
 148    return Res;
 149 }
 150                                                                         /*}}}*/
 151 // Configuration::FindI - Find an integer value                         /*{{{*/
 152 // ---------------------------------------------------------------------
 153 /* */
 154 int Configuration::FindI(const char *Name,int Default)
 155 {
 156    Item *Itm = Lookup(Name,false);
 157    if (Itm == 0 || Itm->Value.empty() == true)
 158       return Default;
 159
 160    char *End;
 161    int Res = strtol(Itm->Value.c_str(),&End,0);
 162    if (End == Itm->Value.c_str())
 163       return Default;
 164
 165    return Res;
 166 }
 167                                                                         /*}}}*/
 168 // Configuration::FindB - Find a boolean type                           /*{{{*/
 169 // ---------------------------------------------------------------------
 170 /* */
 171 bool Configuration::FindB(const char *Name,bool Default)
 172 {
 173    Item *Itm = Lookup(Name,false);
 174    if (Itm == 0 || Itm->Value.empty() == true)
 175       return Default;
 176
 177    return StringToBool(Itm->Value,Default);
 178 }
 179                                                                         /*}}}*/
 180 // Configuration::Set - Set a value                                     /*{{{*/
 181 // ---------------------------------------------------------------------
 182 /* */
 183 void Configuration::Set(const char *Name,string Value)
 184 {
 185    Item *Itm = Lookup(Name,true);
 186    if (Itm == 0)
 187       return;
 188    Itm->Value = Value;
 189 }
 190                                                                         /*}}}*/
 191 // Configuration::Set - Set an integer value                            /*{{{*/
 192 // ---------------------------------------------------------------------
 193 /* */
 194 void Configuration::Set(const char *Name,int Value)
 195 {
 196    Item *Itm = Lookup(Name,true);
 197    if (Itm == 0)
 198       return;
 199    char S[300];
 200    snprintf(S,sizeof(S),"%i",Value);
 201    Itm->Value = S;
 202 }
 203                                                                         /*}}}*/
 204 // Configuration::Exists - Returns true if the Name exists              /*{{{*/
 205 // ---------------------------------------------------------------------
 206 /* */
 207 bool Configuration::Exists(const char *Name)
 208 {
 209    Item *Itm = Lookup(Name,false);
 210    if (Itm == 0)
 211       return false;
 212    return true;
 213 }
 214                                                                         /*}}}*/
 215
 216 // Configuration::Item::FullTag - Return the fully scoped tag           /*{{{*/
 217 // ---------------------------------------------------------------------
 218 /* */
 219 string Configuration::Item::FullTag() const
 220 {
 221    if (Parent == 0 || Parent->Parent == 0)
 222       return Tag;
 223    return Parent->FullTag() + "::" + Tag;
 224 }
 225                                                                         /*}}}*/
 226
 227 // ReadConfigFile - Read a configuration file                           /*{{{*/
 228 // ---------------------------------------------------------------------
 229 /* The configuration format is very much like the named.conf format
 230    used in bind8, in fact this routine can parse most named.conf files. */
 231 bool ReadConfigFile(Configuration &Conf,string FName)
 232 {
 233    // Open the stream for reading
 234    ifstream F(FName.c_str(),ios::in | ios::nocreate);
 235    if (!F != 0)
 236       return _error->Errno("ifstream::ifstream","Opening configuration file %s",FName.c_str());
 237
 238    char Buffer[300];
 239    string LineBuffer;
 240
 241    // Parser state
 242    string ParentTag;
 243
 244    int CurLine = 0;
 245    bool InComment = false;
 246    while (F.eof() == false)
 247    {
 248       F.getline(Buffer,sizeof(Buffer));
 249       CurLine++;
 250       _strtabexpand(Buffer,sizeof(Buffer));
 251       _strstrip(Buffer);
 252
 253       // Multi line comment
 254       if (InComment == true)
 255       {
 256          for (const char *I = Buffer; *I != 0; I++)
 257          {
 258             if (*I == '*' && I[1] == '/')
 259             {
 260                memmove(Buffer,I+2,strlen(I+2) + 1);
 261                InComment = false;
 262                break;
 263             }
 264          }
 265          if (InComment == true)
 266             continue;
 267       }
 268
 269       // Discard single line comments
 270       for (char *I = Buffer; *I != 0; I++)
 271       {
 272          if (*I == '/' && I[1] == '/')
 273          {
 274             *I = 0;
 275             break;
 276          }
 277       }
 278
 279       // Look for multi line comments
 280       for (char *I = Buffer; *I != 0; I++)
 281       {
 282          if (*I == '/' && I[1] == '*')
 283          {
 284             InComment = true;
 285             for (char *J = Buffer; *J != 0; J++)
 286             {
 287                if (*J == '*' && J[1] == '/')
 288                {
 289                   memmove(I,J+2,strlen(J+2) + 1);
 290                   InComment = false;
 291                   break;
 292                }
 293             }
 294
 295             if (InComment == true)
 296             {
 297                *I = 0;
 298                break;
 299             }
 300          }
 301       }
 302
 303       // Blank
 304       if (Buffer[0] == 0)
 305          continue;
 306
 307       // We now have a valid line fragment
 308       for (char *I = Buffer; *I != 0;)
 309       {
 310          if (*I == '{' || *I == ';' || *I == '}')
 311          {
 312             // Put the last fragement into the buffer
 313             char *Start = Buffer;
 314             char *Stop = I;
 315             for (; Start != I && isspace(*Start) != 0; Start++);
 316             for (; Stop != Start && isspace(Stop[-1]) != 0; Stop--);
 317             if (LineBuffer.empty() == false && Stop - Start != 0)
 318                LineBuffer += ' ';
 319             LineBuffer += string(Start,Stop - Start);
 320
 321             // Remove the fragment
 322             char TermChar = *I;
 323             memmove(Buffer,I + 1,strlen(I + 1) + 1);
 324             I = Buffer;
 325
 326             // Move up a tag
 327             if (TermChar == '}')
 328             {
 329                string::size_type Pos = ParentTag.rfind("::");
 330                if (Pos == string::npos)
 331                   ParentTag = string();
 332                else
 333                   ParentTag = string(ParentTag,0,Pos);
 334             }
 335
 336             // Syntax Error
 337             if (TermChar == '{' && LineBuffer.empty() == true)
 338                return _error->Error("Syntax error %s:%u: Block starts with no name.",FName.c_str(),CurLine);
 339
 340             if (LineBuffer.empty() == true)
 341                continue;
 342
 343             // Parse off the tag
 344             string::size_type Pos = LineBuffer.find(' ');
 345             if (Pos == string::npos)
 346             {
 347                if (TermChar == '{')
 348                   Pos = LineBuffer.length();
 349                else
 350                   return _error->Error("Syntax error %s:%u: Tag with no value",FName.c_str(),CurLine);
 351             }
 352
 353             string Tag = string(LineBuffer,0,Pos);
 354
 355             // Go down a level
 356             if (TermChar == '{')
 357             {
 358                if (ParentTag.empty() == true)
 359                   ParentTag = Tag;
 360                else
 361                   ParentTag += string("::") + Tag;
 362                Tag = string();
 363             }
 364
 365             // We dont have a value to set
 366             if (Pos == LineBuffer.length())
 367             {
 368                LineBuffer = string();
 369                continue;
 370             }
 371
 372             // Parse off the word
 373             string Word;
 374             if (ParseCWord(LineBuffer.c_str()+Pos,Word) == false)
 375                return _error->Error("Syntax error %s:%u: Malformed value",FName.c_str(),CurLine);
 376
 377             // Generate the item name
 378             string Item;
 379             if (ParentTag.empty() == true)
 380                Item = Tag;
 381             else
 382             {
 383                if (Tag.empty() == true)
 384                   Item = ParentTag;
 385                else
 386                   Item = ParentTag + "::" + Tag;
 387             }
 388
 389             // Set the item in the configuration class
 390             Conf.Set(Item,Word);
 391
 392             // Empty the buffer
 393             LineBuffer = string();
 394          }
 395          else
 396             I++;
 397       }
 398
 399       // Store the fragment
 400       const char *Stripd = _strstrip(Buffer);
 401       if (*Stripd != 0 && LineBuffer.empty() == false)
 402          LineBuffer += " ";
 403       LineBuffer += Stripd;
 404    }
 405
 406    return true;
 407 }
 408                                                                         /*}}}*/