apt-pkg/contrib/fileutl.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: fileutl.cc,v 1.42 2002/09/14 05:29:22 jgg Exp $
   4 /* ######################################################################
   5
   6    File Utilities
   7
   8    CopyFile - Buffered copy of a single file
   9    GetLock - dpkg compatible lock file manipulation (fcntl)
  10
  11    Most of this source is placed in the Public Domain, do with it what
  12    you will
  13    It was originally written by Jason Gunthorpe <jgg@debian.org>.
  14
  15    The exception is RunScripts() it is under the GPLv2
  16
  17    ##################################################################### */
  18                                                                         /*}}}*/
  19 // Include Files                                                        /*{{{*/
  20 #include <apt-pkg/fileutl.h>
  21 #include <apt-pkg/strutl.h>
  22 #include <apt-pkg/error.h>
  23 #include <apt-pkg/sptr.h>
  24 #include <apt-pkg/configuration.h>
  25
  26 #include <apti18n.h>
  27
  28 #include <cstdlib>
  29 #include <cstring>
  30 #include <cstdio>
  31
  32 #include <iostream>
  33 #include <unistd.h>
  34 #include <fcntl.h>
  35 #include <sys/stat.h>
  36 #include <sys/types.h>
  37 #include <sys/time.h>
  38 #include <sys/wait.h>
  39 #include <dirent.h>
  40 #include <signal.h>
  41 #include <errno.h>
  42 #include <set>
  43 #include <algorithm>
  44                                                                         /*}}}*/
  45
  46 using namespace std;
  47
  48 // RunScripts - Run a set of scripts from a configuration subtree       /*{{{*/
  49 // ---------------------------------------------------------------------
  50 /* */
  51 bool RunScripts(const char *Cnf)
  52 {
  53    Configuration::Item const *Opts = _config->Tree(Cnf);
  54    if (Opts == 0 || Opts->Child == 0)
  55       return true;
  56    Opts = Opts->Child;
  57
  58    // Fork for running the system calls
  59    pid_t Child = ExecFork();
  60
  61    // This is the child
  62    if (Child == 0)
  63    {
  64       if (chdir("/tmp/") != 0)
  65          _exit(100);
  66
  67       unsigned int Count = 1;
  68       for (; Opts != 0; Opts = Opts->Next, Count++)
  69       {
  70          if (Opts->Value.empty() == true)
  71             continue;
  72
  73          if (system(Opts->Value.c_str()) != 0)
  74             _exit(100+Count);
  75       }
  76       _exit(0);
  77    }
  78
  79    // Wait for the child
  80    int Status = 0;
  81    while (waitpid(Child,&Status,0) != Child)
  82    {
  83       if (errno == EINTR)
  84          continue;
  85       return _error->Errno("waitpid","Couldn't wait for subprocess");
  86    }
  87
  88    // Restore sig int/quit
  89    signal(SIGQUIT,SIG_DFL);
  90    signal(SIGINT,SIG_DFL);
  91
  92    // Check for an error code.
  93    if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0)
  94    {
  95       unsigned int Count = WEXITSTATUS(Status);
  96       if (Count > 100)
  97       {
  98          Count -= 100;
  99          for (; Opts != 0 && Count != 1; Opts = Opts->Next, Count--);
 100          _error->Error("Problem executing scripts %s '%s'",Cnf,Opts->Value.c_str());
 101       }
 102
 103       return _error->Error("Sub-process returned an error code");
 104    }
 105
 106    return true;
 107 }
 108                                                                         /*}}}*/
 109
 110 // CopyFile - Buffered copy of a file                                   /*{{{*/
 111 // ---------------------------------------------------------------------
 112 /* The caller is expected to set things so that failure causes erasure */
 113 bool CopyFile(FileFd &From,FileFd &To)
 114 {
 115    if (From.IsOpen() == false || To.IsOpen() == false)
 116       return false;
 117
 118    // Buffered copy between fds
 119    SPtrArray<unsigned char> Buf = new unsigned char[64000];
 120    unsigned long Size = From.Size();
 121    while (Size != 0)
 122    {
 123       unsigned long ToRead = Size;
 124       if (Size > 64000)
 125          ToRead = 64000;
 126
 127       if (From.Read(Buf,ToRead) == false ||
 128           To.Write(Buf,ToRead) == false)
 129          return false;
 130
 131       Size -= ToRead;
 132    }
 133
 134    return true;
 135 }
 136                                                                         /*}}}*/
 137 // GetLock - Gets a lock file                                           /*{{{*/
 138 // ---------------------------------------------------------------------
 139 /* This will create an empty file of the given name and lock it. Once this
 140    is done all other calls to GetLock in any other process will fail with
 141    -1. The return result is the fd of the file, the call should call
 142    close at some time. */
 143 int GetLock(string File,bool Errors)
 144 {
 145    // GetLock() is used in aptitude on directories with public-write access
 146    // Use O_NOFOLLOW here to prevent symlink traversal attacks
 147    int FD = open(File.c_str(),O_RDWR | O_CREAT | O_NOFOLLOW,0640);
 148    if (FD < 0)
 149    {
 150       // Read only .. cant have locking problems there.
 151       if (errno == EROFS)
 152       {
 153          _error->Warning(_("Not using locking for read only lock file %s"),File.c_str());
 154          return dup(0);       // Need something for the caller to close
 155       }
 156
 157       if (Errors == true)
 158          _error->Errno("open",_("Could not open lock file %s"),File.c_str());
 159
 160       // Feh.. We do this to distinguish the lock vs open case..
 161       errno = EPERM;
 162       return -1;
 163    }
 164    SetCloseExec(FD,true);
 165
 166    // Aquire a write lock
 167    struct flock fl;
 168    fl.l_type = F_WRLCK;
 169    fl.l_whence = SEEK_SET;
 170    fl.l_start = 0;
 171    fl.l_len = 0;
 172    if (fcntl(FD,F_SETLK,&fl) == -1)
 173    {
 174       if (errno == ENOLCK)
 175       {
 176          _error->Warning(_("Not using locking for nfs mounted lock file %s"),File.c_str());
 177          return dup(0);       // Need something for the caller to close
 178       }
 179       if (Errors == true)
 180          _error->Errno("open",_("Could not get lock %s"),File.c_str());
 181
 182       int Tmp = errno;
 183       close(FD);
 184       errno = Tmp;
 185       return -1;
 186    }
 187
 188    return FD;
 189 }
 190                                                                         /*}}}*/
 191 // FileExists - Check if a file exists                                  /*{{{*/
 192 // ---------------------------------------------------------------------
 193 /* */
 194 bool FileExists(string File)
 195 {
 196    struct stat Buf;
 197    if (stat(File.c_str(),&Buf) != 0)
 198       return false;
 199    return true;
 200 }
 201                                                                         /*}}}*/
 202 // DirectoryExists - Check if a directory exists and is really one      /*{{{*/
 203 // ---------------------------------------------------------------------
 204 /* */
 205 bool DirectoryExists(string const &Path)
 206 {
 207    struct stat Buf;
 208    if (stat(Path.c_str(),&Buf) != 0)
 209       return false;
 210    return ((Buf.st_mode & S_IFDIR) != 0);
 211 }
 212                                                                         /*}}}*/
 213 // CreateDirectory - poor man's mkdir -p guarded by a parent directory  /*{{{*/
 214 // ---------------------------------------------------------------------
 215 /* This method will create all directories needed for path in good old
 216    mkdir -p style but refuses to do this if Parent is not a prefix of
 217    this Path. Example: /var/cache/ and /var/cache/apt/archives are given,
 218    so it will create apt/archives if /var/cache exists - on the other
 219    hand if the parent is /var/lib the creation will fail as this path
 220    is not a parent of the path to be generated. */
 221 bool CreateDirectory(string const &Parent, string const &Path)
 222 {
 223    if (Parent.empty() == true || Path.empty() == true)
 224       return false;
 225
 226    if (DirectoryExists(Path) == true)
 227       return true;
 228
 229    if (DirectoryExists(Parent) == false)
 230       return false;
 231
 232    // we are not going to create directories "into the blue"
 233    if (Path.find(Parent, 0) != 0)
 234       return false;
 235
 236    vector<string> const dirs = VectorizeString(Path.substr(Parent.size()), '/');
 237    string progress = Parent;
 238    for (vector<string>::const_iterator d = dirs.begin(); d != dirs.end(); ++d)
 239    {
 240       if (d->empty() == true)
 241          continue;
 242
 243       progress.append("/").append(*d);
 244       if (DirectoryExists(progress) == true)
 245          continue;
 246
 247       if (mkdir(progress.c_str(), 0755) != 0)
 248          return false;
 249    }
 250    return true;
 251 }
 252                                                                         /*}}}*/
 253 // GetListOfFilesInDir - returns a vector of files in the given dir     /*{{{*/
 254 // ---------------------------------------------------------------------
 255 /* If an extension is given only files with this extension are included
 256    in the returned vector, otherwise every "normal" file is included. */
 257 std::vector<string> GetListOfFilesInDir(string const &Dir, string const &Ext,
 258                                         bool const &SortList, bool const &AllowNoExt)
 259 {
 260    std::vector<string> ext;
 261    ext.reserve(2);
 262    if (Ext.empty() == false)
 263       ext.push_back(Ext);
 264    if (AllowNoExt == true && ext.empty() == false)
 265       ext.push_back("");
 266    return GetListOfFilesInDir(Dir, ext, SortList);
 267 }
 268 std::vector<string> GetListOfFilesInDir(string const &Dir, std::vector<string> const &Ext,
 269                                         bool const &SortList)
 270 {
 271    // Attention debuggers: need to be set with the environment config file!
 272    bool const Debug = _config->FindB("Debug::GetListOfFilesInDir", false);
 273    if (Debug == true)
 274    {
 275       std::clog << "Accept in " << Dir << " only files with the following " << Ext.size() << " extensions:" << std::endl;
 276       if (Ext.empty() == true)
 277          std::clog << "\tNO extension" << std::endl;
 278       else
 279          for (std::vector<string>::const_iterator e = Ext.begin();
 280               e != Ext.end(); ++e)
 281             std::clog << '\t' << (e->empty() == true ? "NO" : *e) << " extension" << std::endl;
 282    }
 283
 284    std::vector<string> List;
 285    Configuration::MatchAgainstConfig SilentIgnore("Dir::Ignore-Files-Silently");
 286    DIR *D = opendir(Dir.c_str());
 287    if (D == 0)
 288    {
 289       _error->Errno("opendir",_("Unable to read %s"),Dir.c_str());
 290       return List;
 291    }
 292
 293    for (struct dirent *Ent = readdir(D); Ent != 0; Ent = readdir(D))
 294    {
 295       // skip "hidden" files
 296       if (Ent->d_name[0] == '.')
 297          continue;
 298
 299       // check for accepted extension:
 300       // no extension given -> periods are bad as hell!
 301       // extensions given -> "" extension allows no extension
 302       if (Ext.empty() == false)
 303       {
 304          string d_ext = flExtension(Ent->d_name);
 305          if (d_ext == Ent->d_name) // no extension
 306          {
 307             if (std::find(Ext.begin(), Ext.end(), "") == Ext.end())
 308             {
 309                if (Debug == true)
 310                   std::clog << "Bad file: " << Ent->d_name << " → no extension" << std::endl;
 311                _error->Notice("Ignoring file '%s' in directory '%s' as it has no filename extension", Ent->d_name, Dir.c_str());
 312                continue;
 313             }
 314          }
 315          else if (std::find(Ext.begin(), Ext.end(), d_ext) == Ext.end())
 316          {
 317             if (Debug == true)
 318                std::clog << "Bad file: " << Ent->d_name << " → bad extension »" << flExtension(Ent->d_name) << "«" << std::endl;
 319             if (SilentIgnore.Match(Ent->d_name) == false)
 320                _error->Notice("Ignoring file '%s' in directory '%s' as it has an invalid filename extension", Ent->d_name, Dir.c_str());
 321             continue;
 322          }
 323       }
 324
 325       // Skip bad filenames ala run-parts
 326       const char *C = Ent->d_name;
 327       for (; *C != 0; ++C)
 328          if (isalpha(*C) == 0 && isdigit(*C) == 0
 329              && *C != '_' && *C != '-') {
 330             // no required extension -> dot is a bad character
 331             if (*C == '.' && Ext.empty() == false)
 332                continue;
 333             break;
 334          }
 335
 336       // we don't reach the end of the name -> bad character included
 337       if (*C != 0)
 338       {
 339          if (Debug == true)
 340             std::clog << "Bad file: " << Ent->d_name << " → bad character »"
 341                << *C << "« in filename (period allowed: " << (Ext.empty() ? "no" : "yes") << ")" << std::endl;
 342          continue;
 343       }
 344
 345       // skip filenames which end with a period. These are never valid
 346       if (*(C - 1) == '.')
 347       {
 348          if (Debug == true)
 349             std::clog << "Bad file: " << Ent->d_name << " → Period as last character" << std::endl;
 350          continue;
 351       }
 352
 353       // Make sure it is a file and not something else
 354       string const File = flCombine(Dir,Ent->d_name);
 355       struct stat St;
 356       if (stat(File.c_str(),&St) != 0 || S_ISREG(St.st_mode) == 0)
 357       {
 358          if (Debug == true)
 359             std::clog << "Bad file: " << Ent->d_name << " → stat says not a good file" << std::endl;
 360          continue;
 361       }
 362
 363       if (Debug == true)
 364          std::clog << "Accept file: " << Ent->d_name << " in " << Dir << std::endl;
 365       List.push_back(File);
 366    }
 367    closedir(D);
 368
 369    if (SortList == true)
 370       std::sort(List.begin(),List.end());
 371    return List;
 372 }
 373                                                                         /*}}}*/
 374 // SafeGetCWD - This is a safer getcwd that returns a dynamic string    /*{{{*/
 375 // ---------------------------------------------------------------------
 376 /* We return / on failure. */
 377 string SafeGetCWD()
 378 {
 379    // Stash the current dir.
 380    char S[300];
 381    S[0] = 0;
 382    if (getcwd(S,sizeof(S)-2) == 0)
 383       return "/";
 384    unsigned int Len = strlen(S);
 385    S[Len] = '/';
 386    S[Len+1] = 0;
 387    return S;
 388 }
 389                                                                         /*}}}*/
 390 // flNotDir - Strip the directory from the filename                     /*{{{*/
 391 // ---------------------------------------------------------------------
 392 /* */
 393 string flNotDir(string File)
 394 {
 395    string::size_type Res = File.rfind('/');
 396    if (Res == string::npos)
 397       return File;
 398    Res++;
 399    return string(File,Res,Res - File.length());
 400 }
 401                                                                         /*}}}*/
 402 // flNotFile - Strip the file from the directory name                   /*{{{*/
 403 // ---------------------------------------------------------------------
 404 /* Result ends in a / */
 405 string flNotFile(string File)
 406 {
 407    string::size_type Res = File.rfind('/');
 408    if (Res == string::npos)
 409       return "./";
 410    Res++;
 411    return string(File,0,Res);
 412 }
 413                                                                         /*}}}*/
 414 // flExtension - Return the extension for the file                      /*{{{*/
 415 // ---------------------------------------------------------------------
 416 /* */
 417 string flExtension(string File)
 418 {
 419    string::size_type Res = File.rfind('.');
 420    if (Res == string::npos)
 421       return File;
 422    Res++;
 423    return string(File,Res,Res - File.length());
 424 }
 425                                                                         /*}}}*/
 426 // flNoLink - If file is a symlink then deref it                        /*{{{*/
 427 // ---------------------------------------------------------------------
 428 /* If the name is not a link then the returned path is the input. */
 429 string flNoLink(string File)
 430 {
 431    struct stat St;
 432    if (lstat(File.c_str(),&St) != 0 || S_ISLNK(St.st_mode) == 0)
 433       return File;
 434    if (stat(File.c_str(),&St) != 0)
 435       return File;
 436
 437    /* Loop resolving the link. There is no need to limit the number of
 438       loops because the stat call above ensures that the symlink is not
 439       circular */
 440    char Buffer[1024];
 441    string NFile = File;
 442    while (1)
 443    {
 444       // Read the link
 445       int Res;
 446       if ((Res = readlink(NFile.c_str(),Buffer,sizeof(Buffer))) <= 0 ||
 447           (unsigned)Res >= sizeof(Buffer))
 448           return File;
 449
 450       // Append or replace the previous path
 451       Buffer[Res] = 0;
 452       if (Buffer[0] == '/')
 453          NFile = Buffer;
 454       else
 455          NFile = flNotFile(NFile) + Buffer;
 456
 457       // See if we are done
 458       if (lstat(NFile.c_str(),&St) != 0)
 459          return File;
 460       if (S_ISLNK(St.st_mode) == 0)
 461          return NFile;
 462    }
 463 }
 464                                                                         /*}}}*/
 465 // flCombine - Combine a file and a directory                           /*{{{*/
 466 // ---------------------------------------------------------------------
 467 /* If the file is an absolute path then it is just returned, otherwise
 468    the directory is pre-pended to it. */
 469 string flCombine(string Dir,string File)
 470 {
 471    if (File.empty() == true)
 472       return string();
 473
 474    if (File[0] == '/' || Dir.empty() == true)
 475       return File;
 476    if (File.length() >= 2 && File[0] == '.' && File[1] == '/')
 477       return File;
 478    if (Dir[Dir.length()-1] == '/')
 479       return Dir + File;
 480    return Dir + '/' + File;
 481 }
 482                                                                         /*}}}*/
 483 // SetCloseExec - Set the close on exec flag                            /*{{{*/
 484 // ---------------------------------------------------------------------
 485 /* */
 486 void SetCloseExec(int Fd,bool Close)
 487 {
 488    if (fcntl(Fd,F_SETFD,(Close == false)?0:FD_CLOEXEC) != 0)
 489    {
 490       cerr << "FATAL -> Could not set close on exec " << strerror(errno) << endl;
 491       exit(100);
 492    }
 493 }
 494                                                                         /*}}}*/
 495 // SetNonBlock - Set the nonblocking flag                               /*{{{*/
 496 // ---------------------------------------------------------------------
 497 /* */
 498 void SetNonBlock(int Fd,bool Block)
 499 {
 500    int Flags = fcntl(Fd,F_GETFL) & (~O_NONBLOCK);
 501    if (fcntl(Fd,F_SETFL,Flags | ((Block == false)?0:O_NONBLOCK)) != 0)
 502    {
 503       cerr << "FATAL -> Could not set non-blocking flag " << strerror(errno) << endl;
 504       exit(100);
 505    }
 506 }
 507                                                                         /*}}}*/
 508 // WaitFd - Wait for a FD to become readable                            /*{{{*/
 509 // ---------------------------------------------------------------------
 510 /* This waits for a FD to become readable using select. It is useful for
 511    applications making use of non-blocking sockets. The timeout is
 512    in seconds. */
 513 bool WaitFd(int Fd,bool write,unsigned long timeout)
 514 {
 515    fd_set Set;
 516    struct timeval tv;
 517    FD_ZERO(&Set);
 518    FD_SET(Fd,&Set);
 519    tv.tv_sec = timeout;
 520    tv.tv_usec = 0;
 521    if (write == true)
 522    {
 523       int Res;
 524       do
 525       {
 526          Res = select(Fd+1,0,&Set,0,(timeout != 0?&tv:0));
 527       }
 528       while (Res < 0 && errno == EINTR);
 529
 530       if (Res <= 0)
 531          return false;
 532    }
 533    else
 534    {
 535       int Res;
 536       do
 537       {
 538          Res = select(Fd+1,&Set,0,0,(timeout != 0?&tv:0));
 539       }
 540       while (Res < 0 && errno == EINTR);
 541
 542       if (Res <= 0)
 543          return false;
 544    }
 545
 546    return true;
 547 }
 548                                                                         /*}}}*/
 549 // ExecFork - Magical fork that sanitizes the context before execing    /*{{{*/
 550 // ---------------------------------------------------------------------
 551 /* This is used if you want to cleanse the environment for the forked
 552    child, it fixes up the important signals and nukes all of the fds,
 553    otherwise acts like normal fork. */
 554 pid_t ExecFork()
 555 {
 556    // Fork off the process
 557    pid_t Process = fork();
 558    if (Process < 0)
 559    {
 560       cerr << "FATAL -> Failed to fork." << endl;
 561       exit(100);
 562    }
 563
 564    // Spawn the subprocess
 565    if (Process == 0)
 566    {
 567       // Setup the signals
 568       signal(SIGPIPE,SIG_DFL);
 569       signal(SIGQUIT,SIG_DFL);
 570       signal(SIGINT,SIG_DFL);
 571       signal(SIGWINCH,SIG_DFL);
 572       signal(SIGCONT,SIG_DFL);
 573       signal(SIGTSTP,SIG_DFL);
 574
 575       set<int> KeepFDs;
 576       Configuration::Item const *Opts = _config->Tree("APT::Keep-Fds");
 577       if (Opts != 0 && Opts->Child != 0)
 578       {
 579          Opts = Opts->Child;
 580          for (; Opts != 0; Opts = Opts->Next)
 581          {
 582             if (Opts->Value.empty() == true)
 583                continue;
 584             int fd = atoi(Opts->Value.c_str());
 585             KeepFDs.insert(fd);
 586          }
 587       }
 588
 589       // Close all of our FDs - just in case
 590       for (int K = 3; K != 40; K++)
 591       {
 592          if(KeepFDs.find(K) == KeepFDs.end())
 593             fcntl(K,F_SETFD,FD_CLOEXEC);
 594       }
 595    }
 596
 597    return Process;
 598 }
 599                                                                         /*}}}*/
 600 // ExecWait - Fancy waitpid                                             /*{{{*/
 601 // ---------------------------------------------------------------------
 602 /* Waits for the given sub process. If Reap is set then no errors are
 603    generated. Otherwise a failed subprocess will generate a proper descriptive
 604    message */
 605 bool ExecWait(pid_t Pid,const char *Name,bool Reap)
 606 {
 607    if (Pid <= 1)
 608       return true;
 609
 610    // Wait and collect the error code
 611    int Status;
 612    while (waitpid(Pid,&Status,0) != Pid)
 613    {
 614       if (errno == EINTR)
 615          continue;
 616
 617       if (Reap == true)
 618          return false;
 619
 620       return _error->Error(_("Waited for %s but it wasn't there"),Name);
 621    }
 622
 623
 624    // Check for an error code.
 625    if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0)
 626    {
 627       if (Reap == true)
 628          return false;
 629       if (WIFSIGNALED(Status) != 0)
 630       {
 631          if( WTERMSIG(Status) == SIGSEGV)
 632             return _error->Error(_("Sub-process %s received a segmentation fault."),Name);
 633          else
 634             return _error->Error(_("Sub-process %s received signal %u."),Name, WTERMSIG(Status));
 635       }
 636
 637       if (WIFEXITED(Status) != 0)
 638          return _error->Error(_("Sub-process %s returned an error code (%u)"),Name,WEXITSTATUS(Status));
 639
 640       return _error->Error(_("Sub-process %s exited unexpectedly"),Name);
 641    }
 642
 643    return true;
 644 }
 645                                                                         /*}}}*/
 646
 647 // FileFd::Open - Open a file                                           /*{{{*/
 648 // ---------------------------------------------------------------------
 649 /* The most commonly used open mode combinations are given with Mode */
 650 bool FileFd::Open(string FileName,OpenMode Mode, unsigned long Perms)
 651 {
 652    Close();
 653    Flags = AutoClose;
 654    switch (Mode)
 655    {
 656       case ReadOnly:
 657       iFd = open(FileName.c_str(),O_RDONLY);
 658       break;
 659
 660       case WriteEmpty:
 661       {
 662          Flags |= Replace;
 663          char *name = strdup((FileName + ".XXXXXX").c_str());
 664          TemporaryFileName = string(mktemp(name));
 665          iFd = open(TemporaryFileName.c_str(),O_RDWR | O_CREAT | O_EXCL,Perms);
 666          free(name);
 667          break;
 668       }
 669
 670       case WriteExists:
 671       iFd = open(FileName.c_str(),O_RDWR);
 672       break;
 673
 674       case WriteAny:
 675       iFd = open(FileName.c_str(),O_RDWR | O_CREAT,Perms);
 676       break;
 677
 678       case WriteTemp:
 679       unlink(FileName.c_str());
 680       iFd = open(FileName.c_str(),O_RDWR | O_CREAT | O_EXCL,Perms);
 681       break;
 682    }
 683
 684    if (iFd < 0)
 685       return _error->Errno("open",_("Could not open file %s"),FileName.c_str());
 686
 687    this->FileName = FileName;
 688    SetCloseExec(iFd,true);
 689    return true;
 690 }
 691                                                                         /*}}}*/
 692 // FileFd::~File - Closes the file                                      /*{{{*/
 693 // ---------------------------------------------------------------------
 694 /* If the proper modes are selected then we close the Fd and possibly
 695    unlink the file on error. */
 696 FileFd::~FileFd()
 697 {
 698    Close();
 699 }
 700                                                                         /*}}}*/
 701 // FileFd::Read - Read a bit of the file                                /*{{{*/
 702 // ---------------------------------------------------------------------
 703 /* We are carefull to handle interruption by a signal while reading
 704    gracefully. */
 705 bool FileFd::Read(void *To,unsigned long Size,unsigned long *Actual)
 706 {
 707    int Res;
 708    errno = 0;
 709    if (Actual != 0)
 710       *Actual = 0;
 711
 712    do
 713    {
 714       Res = read(iFd,To,Size);
 715       if (Res < 0 && errno == EINTR)
 716          continue;
 717       if (Res < 0)
 718       {
 719          Flags |= Fail;
 720          return _error->Errno("read",_("Read error"));
 721       }
 722
 723       To = (char *)To + Res;
 724       Size -= Res;
 725       if (Actual != 0)
 726          *Actual += Res;
 727    }
 728    while (Res > 0 && Size > 0);
 729
 730    if (Size == 0)
 731       return true;
 732
 733    // Eof handling
 734    if (Actual != 0)
 735    {
 736       Flags |= HitEof;
 737       return true;
 738    }
 739
 740    Flags |= Fail;
 741    return _error->Error(_("read, still have %lu to read but none left"),Size);
 742 }
 743                                                                         /*}}}*/
 744 // FileFd::Write - Write to the file                                    /*{{{*/
 745 // ---------------------------------------------------------------------
 746 /* */
 747 bool FileFd::Write(const void *From,unsigned long Size)
 748 {
 749    int Res;
 750    errno = 0;
 751    do
 752    {
 753       Res = write(iFd,From,Size);
 754       if (Res < 0 && errno == EINTR)
 755          continue;
 756       if (Res < 0)
 757       {
 758          Flags |= Fail;
 759          return _error->Errno("write",_("Write error"));
 760       }
 761
 762       From = (char *)From + Res;
 763       Size -= Res;
 764    }
 765    while (Res > 0 && Size > 0);
 766
 767    if (Size == 0)
 768       return true;
 769
 770    Flags |= Fail;
 771    return _error->Error(_("write, still have %lu to write but couldn't"),Size);
 772 }
 773                                                                         /*}}}*/
 774 // FileFd::Seek - Seek in the file                                      /*{{{*/
 775 // ---------------------------------------------------------------------
 776 /* */
 777 bool FileFd::Seek(unsigned long To)
 778 {
 779    if (lseek(iFd,To,SEEK_SET) != (signed)To)
 780    {
 781       Flags |= Fail;
 782       return _error->Error("Unable to seek to %lu",To);
 783    }
 784
 785    return true;
 786 }
 787                                                                         /*}}}*/
 788 // FileFd::Skip - Seek in the file                                      /*{{{*/
 789 // ---------------------------------------------------------------------
 790 /* */
 791 bool FileFd::Skip(unsigned long Over)
 792 {
 793    if (lseek(iFd,Over,SEEK_CUR) < 0)
 794    {
 795       Flags |= Fail;
 796       return _error->Error("Unable to seek ahead %lu",Over);
 797    }
 798
 799    return true;
 800 }
 801                                                                         /*}}}*/
 802 // FileFd::Truncate - Truncate the file                                 /*{{{*/
 803 // ---------------------------------------------------------------------
 804 /* */
 805 bool FileFd::Truncate(unsigned long To)
 806 {
 807    if (ftruncate(iFd,To) != 0)
 808    {
 809       Flags |= Fail;
 810       return _error->Error("Unable to truncate to %lu",To);
 811    }
 812
 813    return true;
 814 }
 815                                                                         /*}}}*/
 816 // FileFd::Tell - Current seek position                                 /*{{{*/
 817 // ---------------------------------------------------------------------
 818 /* */
 819 unsigned long FileFd::Tell()
 820 {
 821    off_t Res = lseek(iFd,0,SEEK_CUR);
 822    if (Res == (off_t)-1)
 823       _error->Errno("lseek","Failed to determine the current file position");
 824    return Res;
 825 }
 826                                                                         /*}}}*/
 827 // FileFd::Size - Return the size of the file                           /*{{{*/
 828 // ---------------------------------------------------------------------
 829 /* */
 830 unsigned long FileFd::Size()
 831 {
 832    struct stat Buf;
 833    if (fstat(iFd,&Buf) != 0)
 834       return _error->Errno("fstat","Unable to determine the file size");
 835    return Buf.st_size;
 836 }
 837                                                                         /*}}}*/
 838 // FileFd::Close - Close the file if the close flag is set              /*{{{*/
 839 // ---------------------------------------------------------------------
 840 /* */
 841 bool FileFd::Close()
 842 {
 843    bool Res = true;
 844    if ((Flags & AutoClose) == AutoClose)
 845       if (iFd >= 0 && close(iFd) != 0)
 846          Res &= _error->Errno("close",_("Problem closing the file"));
 847    iFd = -1;
 848
 849    if ((Flags & Replace) == Replace) {
 850       if (rename(TemporaryFileName.c_str(), FileName.c_str()) != 0)
 851          Res &= _error->Errno("rename",_("Problem renaming the file"));
 852       FileName = TemporaryFileName; // for the unlink() below.
 853    }
 854
 855    if ((Flags & Fail) == Fail && (Flags & DelOnFail) == DelOnFail &&
 856        FileName.empty() == false)
 857       if (unlink(FileName.c_str()) != 0)
 858          Res &= _error->WarningE("unlnk",_("Problem unlinking the file"));
 859
 860
 861    return Res;
 862 }
 863                                                                         /*}}}*/
 864 // FileFd::Sync - Sync the file                                         /*{{{*/
 865 // ---------------------------------------------------------------------
 866 /* */
 867 bool FileFd::Sync()
 868 {
 869 #ifdef _POSIX_SYNCHRONIZED_IO
 870    if (fsync(iFd) != 0)
 871       return _error->Errno("sync",_("Problem syncing the file"));
 872 #endif
 873    return true;
 874 }
 875                                                                         /*}}}*/