apt-pkg/contrib/fileutl.h

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: fileutl.h,v 1.26 2001/05/07 05:06:52 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    FileExists - Returns true if the file exists
  11    SafeGetCWD - Returns the CWD in a string with overrun protection
  12
  13    The file class is a handy abstraction for various functions+classes
  14    that need to accept filenames.
  15
  16    This source is placed in the Public Domain, do with it what you will
  17    It was originally written by Jason Gunthorpe.
  18
  19    ##################################################################### */
  20                                                                         /*}}}*/
  21 #ifndef PKGLIB_FILEUTL_H
  22 #define PKGLIB_FILEUTL_H
  23
  24 #include <apt-pkg/macros.h>
  25 #include <apt-pkg/aptconfiguration.h>
  26
  27 #include <string>
  28 #include <vector>
  29 #include <set>
  30 #include <time.h>
  31
  32 #include <zlib.h>
  33
  34 #ifndef APT_8_CLEANER_HEADERS
  35 using std::string;
  36 #endif
  37
  38 /* Define this for python-apt */
  39 #define APT_HAS_GZIP 1
  40
  41 class FileFdPrivate;
  42 class FileFd
  43 {
  44    friend class FileFdPrivate;
  45    friend class GzipFileFdPrivate;
  46    friend class Bz2FileFdPrivate;
  47    friend class LzmaFileFdPrivate;
  48    friend class DirectFileFdPrivate;
  49    friend class PipedFileFdPrivate;
  50    protected:
  51    int iFd;
  52
  53    enum LocalFlags {AutoClose = (1<<0),Fail = (1<<1),DelOnFail = (1<<2),
  54                     HitEof = (1<<3), Replace = (1<<4), Compressed = (1<<5) };
  55    unsigned long Flags;
  56    std::string FileName;
  57    std::string TemporaryFileName;
  58
  59    public:
  60    enum OpenMode {
  61         ReadOnly = (1 << 0),
  62         WriteOnly = (1 << 1),
  63         ReadWrite = ReadOnly | WriteOnly,
  64
  65         Create = (1 << 2),
  66         Exclusive = (1 << 3),
  67         Atomic = Exclusive | (1 << 4),
  68         Empty = (1 << 5),
  69
  70         WriteEmpty = ReadWrite | Create | Empty,
  71         WriteExists = ReadWrite,
  72         WriteAny = ReadWrite | Create,
  73         WriteTemp = ReadWrite | Create | Exclusive,
  74         ReadOnlyGzip,
  75         WriteAtomic = ReadWrite | Create | Atomic
  76    };
  77    enum CompressMode { Auto = 'A', None = 'N', Extension = 'E', Gzip = 'G', Bzip2 = 'B', Lzma = 'L', Xz = 'X' };
  78
  79    inline bool Read(void *To,unsigned long long Size,bool AllowEof)
  80    {
  81       unsigned long long Jnk;
  82       if (AllowEof)
  83          return Read(To,Size,&Jnk);
  84       return Read(To,Size);
  85    }
  86    bool Read(void *To,unsigned long long Size,unsigned long long *Actual = 0);
  87    char* ReadLine(char *To, unsigned long long const Size);
  88    bool Flush();
  89    bool Write(const void *From,unsigned long long Size);
  90    bool static Write(int Fd, const void *From, unsigned long long Size);
  91    bool Seek(unsigned long long To);
  92    bool Skip(unsigned long long To);
  93    bool Truncate(unsigned long long To);
  94    unsigned long long Tell();
  95    // the size of the file content (compressed files will be uncompressed first)
  96    unsigned long long Size();
  97    // the size of the file itself
  98    unsigned long long FileSize();
  99    time_t ModificationTime();
 100
 101    /* You want to use 'unsigned long long' if you are talking about a file
 102       to be able to support large files (>2 or >4 GB) properly.
 103       This shouldn't happen all to often for the indexes, but deb's might be…
 104       And as the auto-conversation converts a 'unsigned long *' to a 'bool'
 105       instead of 'unsigned long long *' we need to provide this explicitly -
 106       otherwise applications magically start to fail… */
 107    bool Read(void *To,unsigned long long Size,unsigned long *Actual) APT_DEPRECATED_MSG("The Actual variable you pass in should be an unsigned long long")
 108    {
 109         unsigned long long R;
 110         bool const T = Read(To, Size, &R);
 111         *Actual = R;
 112         return T;
 113    }
 114
 115    bool Open(std::string FileName,unsigned int const Mode,CompressMode Compress,unsigned long const AccessMode = 0666);
 116    bool Open(std::string FileName,unsigned int const Mode,APT::Configuration::Compressor const &compressor,unsigned long const AccessMode = 0666);
 117    inline bool Open(std::string const &FileName,unsigned int const Mode, unsigned long const AccessMode = 0666) {
 118       return Open(FileName, Mode, None, AccessMode);
 119    };
 120    bool OpenDescriptor(int Fd, unsigned int const Mode, CompressMode Compress, bool AutoClose=false);
 121    bool OpenDescriptor(int Fd, unsigned int const Mode, APT::Configuration::Compressor const &compressor, bool AutoClose=false);
 122    inline bool OpenDescriptor(int Fd, unsigned int const Mode, bool AutoClose=false) {
 123       return OpenDescriptor(Fd, Mode, None, AutoClose);
 124    };
 125    bool Close();
 126    bool Sync();
 127
 128    // Simple manipulators
 129    inline int Fd() {return iFd;};
 130    inline void Fd(int fd) { OpenDescriptor(fd, ReadWrite);};
 131    gzFile gzFd() APT_DEPRECATED_MSG("Implementation detail, do not use to be able to support bzip2, xz and co") APT_PURE;
 132
 133    inline bool IsOpen() {return iFd >= 0;};
 134    inline bool Failed() {return (Flags & Fail) == Fail;};
 135    inline void EraseOnFailure() {Flags |= DelOnFail;};
 136    inline void OpFail() {Flags |= Fail;};
 137    inline bool Eof() {return (Flags & HitEof) == HitEof;};
 138    inline bool IsCompressed() {return (Flags & Compressed) == Compressed;};
 139    inline std::string &Name() {return FileName;};
 140
 141    FileFd(std::string FileName,unsigned int const Mode,unsigned long AccessMode = 0666);
 142    FileFd(std::string FileName,unsigned int const Mode, CompressMode Compress, unsigned long AccessMode = 0666);
 143    FileFd();
 144    FileFd(int const Fd, unsigned int const Mode = ReadWrite, CompressMode Compress = None);
 145    FileFd(int const Fd, bool const AutoClose);
 146    virtual ~FileFd();
 147
 148    private:
 149    FileFdPrivate * d;
 150    APT_HIDDEN FileFd & operator=(const FileFd &);
 151    APT_HIDDEN bool OpenInternDescriptor(unsigned int const Mode, APT::Configuration::Compressor const &compressor);
 152
 153    // private helpers to set Fail flag and call _error->Error
 154    APT_HIDDEN bool FileFdErrno(const char* Function, const char* Description,...) APT_PRINTF(3) APT_COLD;
 155    APT_HIDDEN bool FileFdError(const char* Description,...) APT_PRINTF(2) APT_COLD;
 156 };
 157
 158 bool RunScripts(const char *Cnf);
 159 bool CopyFile(FileFd &From,FileFd &To);
 160 bool RemoveFile(char const * const Function, std::string const &FileName);
 161 int GetLock(std::string File,bool Errors = true);
 162 bool FileExists(std::string File);
 163 bool RealFileExists(std::string File);
 164 bool DirectoryExists(std::string const &Path) APT_CONST;
 165 bool CreateDirectory(std::string const &Parent, std::string const &Path);
 166 time_t GetModificationTime(std::string const &Path);
 167 bool Rename(std::string From, std::string To);
 168
 169 std::string GetTempDir();
 170 std::string GetTempDir(std::string const &User);
 171 FileFd* GetTempFile(std::string const &Prefix = "",
 172                     bool ImmediateUnlink = true,
 173                     FileFd * const TmpFd = NULL);
 174
 175 /** \brief Ensure the existence of the given Path
 176  *
 177  *  \param Parent directory of the Path directory - a trailing
 178  *  /apt/ will be removed before CreateDirectory call.
 179  *  \param Path which should exist after (successful) call
 180  */
 181 bool CreateAPTDirectoryIfNeeded(std::string const &Parent, std::string const &Path);
 182
 183 std::vector<std::string> GetListOfFilesInDir(std::string const &Dir, std::string const &Ext,
 184                                         bool const &SortList, bool const &AllowNoExt=false);
 185 std::vector<std::string> GetListOfFilesInDir(std::string const &Dir, std::vector<std::string> const &Ext,
 186                                         bool const &SortList);
 187 std::vector<std::string> GetListOfFilesInDir(std::string const &Dir, bool SortList);
 188 std::string SafeGetCWD();
 189 void SetCloseExec(int Fd,bool Close);
 190 void SetNonBlock(int Fd,bool Block);
 191 bool WaitFd(int Fd,bool write = false,unsigned long timeout = 0);
 192 pid_t ExecFork();
 193 pid_t ExecFork(std::set<int> keep_fds);
 194 void MergeKeepFdsFromConfiguration(std::set<int> &keep_fds);
 195 bool ExecWait(pid_t Pid,const char *Name,bool Reap = false);
 196
 197 // check if the given file starts with a PGP cleartext signature
 198 bool StartsWithGPGClearTextSignature(std::string const &FileName);
 199
 200 /** change file attributes to requested known good values
 201  *
 202  * The method skips the user:group setting if not root.
 203  *
 204  * @param requester is printed as functionname in error cases
 205  * @param file is the file to be modified
 206  * @param user is the (new) owner of the file, e.g. _apt
 207  * @param group is the (new) group owning the file, e.g. root
 208  * @param mode is the access mode of the file, e.g. 0644
 209  */
 210 bool ChangeOwnerAndPermissionOfFile(char const * const requester, char const * const file, char const * const user, char const * const group, mode_t const mode);
 211
 212 /**
 213  * \brief Drop privileges
 214  *
 215  * Drop the privileges to the user _apt (or the one specified in
 216  * APT::Sandbox::User). This does not set the supplementary group
 217  * ids up correctly, it only uses the default group. Also prevent
 218  * the process from gaining any new privileges afterwards, at least
 219  * on Linux.
 220  *
 221  * \return true on success, false on failure with _error set
 222  */
 223 bool DropPrivileges();
 224
 225 // File string manipulators
 226 std::string flNotDir(std::string File);
 227 std::string flNotFile(std::string File);
 228 std::string flNoLink(std::string File);
 229 std::string flExtension(std::string File);
 230 std::string flCombine(std::string Dir,std::string File);
 231
 232 /** \brief Takes a file path and returns the absolute path
 233  */
 234 std::string flAbsPath(std::string File);
 235
 236 // simple c++ glob
 237 std::vector<std::string> Glob(std::string const &pattern, int flags=0);
 238
 239 /** \brief Popen() implementation that execv() instead of using a shell
 240  *
 241  * \param Args the execv style command to run
 242  * \param FileFd is a referenz to the FileFd to use for input or output
 243  * \param Child a reference to the integer that stores the child pid
 244  *        Note that you must call ExecWait() or similar to cleanup
 245  * \param Mode is either FileFd::ReadOnly or FileFd::WriteOnly
 246  * \return true on success, false on failure with _error set
 247  */
 248 bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode);
 249
 250
 251 #endif