Base revisions

Author: jgg
Date: 1998-07-02 02:58:12 GMT
Base revisions

1 files changed, 214 insertions, 0 deletions

diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
new file mode 100644
index 000000000..6048ff0bb
--- /dev/null
+++ b/apt-pkg/contrib/fileutl.cc
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+// -*- mode: cpp; mode: fold -*-
+// Description								/*{{{*/
+// $Id: fileutl.cc,v 1.1 1998/07/02 02:58:13 jgg Exp $
+/* ######################################################################
+   
+   File Utilities
+   
+   CopyFile - Buffered copy of a single file
+   GetLock - dpkg compatible lock file manipulation (fcntl)
+   
+   This source is placed in the Public Domain, do with it what you will
+   It was originally written by Jason Gunthorpe.
+   
+   ##################################################################### */
+									/*}}}*/
+// Include Files							/*{{{*/
+#include <fileutl.h>
+#include <pkglib/error.h>
+
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/fcntl.h>
+#include <sys/types.h>
+									/*}}}*/
+
+// CopyFile - Buffered copy of a file					/*{{{*/
+// ---------------------------------------------------------------------
+/* The caller is expected to set things so that failure causes erasure */
+bool CopyFile(File From,File To)
+{
+   if (From.IsOpen() == false || To.IsOpen() == false)
+      return false;
+   
+   // Buffered copy between fds
+   unsigned char *Buf = new unsigned char[64000];
+   long Size;
+   while ((Size = read(From.Fd(),Buf,64000)) > 0)
+   {
+      if (To.Write(Buf,Size) == false)
+      {
+	 delete [] Buf;
+	 return false;
+      }
+   }
+
+   delete [] Buf;
+   return true;   
+}
+									/*}}}*/
+// GetLock - Gets a lock file						/*{{{*/
+// ---------------------------------------------------------------------
+/* This will create an empty file of the given name and lock it. Once this
+   is done all other calls to GetLock in any other process will fail with
+   -1. The return result is the fd of the file, the call should call
+   close at some time. */
+int GetLock(string File,bool Errors)
+{
+   int FD = open(File.c_str(),O_RDWR | O_CREAT | O_TRUNC,0640);
+   if (FD < 0)
+   {
+      if (Errors == true)
+	 _error->Errno("open","Could not open lock file %s",File.c_str());
+      return -1;
+   }
+   
+   // Aquire a write lock
+   struct flock fl;
+   fl.l_type= F_WRLCK;
+   fl.l_whence= SEEK_SET;
+   fl.l_start= 0;
+   fl.l_len= 1;
+   if (fcntl(FD,F_SETLK,&fl) == -1)
+   {
+      if (Errors == true)
+	 _error->Errno("open","Could not get lock %s",File.c_str());
+      close(FD);
+      return -1;
+   }
+
+   return FD;
+}
+									/*}}}*/
+// FileExists - Check if a file exists					/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool FileExists(string File)
+{
+   struct stat Buf;
+   if (stat(File.c_str(),&Buf) != 0)
+      return false;
+   return true;
+}
+									/*}}}*/
+// SafeGetCWD - This is a safer getcwd that returns a dynamic string	/*{{{*/
+// ---------------------------------------------------------------------
+/* We return / on failure. */
+string SafeGetCWD()
+{
+   // Stash the current dir.
+   char S[300];
+   S[0] = 0;
+   if (getcwd(S,sizeof(S)) == 0)
+      return "/";
+   return S;
+}
+									/*}}}*/
+
+// File::File - Open a file						/*{{{*/
+// ---------------------------------------------------------------------
+/* The most commonly used open mode combinations are given with Mode */
+File::File(string FileName,OpenMode Mode, unsigned long Perms)
+{
+   Flags = 0;
+   switch (Mode)
+   {
+      case ReadOnly:
+      iFd = open(FileName.c_str(),O_RDONLY);
+      break;
+      
+      case WriteEmpty:
+      unlink(FileName.c_str());
+      iFd = open(FileName.c_str(),O_RDWR | O_CREAT | O_EXCL,Perms);
+      break;
+      
+      case WriteExists:
+      iFd = open(FileName.c_str(),O_RDWR);
+      break;
+   }  
+
+   if (iFd < 0)
+      _error->Errno("open","Could not open file %s",FileName.c_str());
+   else
+      this->FileName = FileName;
+}
+									/*}}}*/
+// File::~File - Closes the file					/*{{{*/
+// ---------------------------------------------------------------------
+/* If the proper modes are selected then we close the Fd and possibly
+   unlink the file on error. */
+File::~File()
+{
+   Close();
+}
+									/*}}}*/
+// File::Read - Read a bit of the file					/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool File::Read(void *To,unsigned long Size)
+{
+   if (read(iFd,To,Size) != (signed)Size)
+   {
+      Flags |= Fail;
+      return _error->Errno("read","Read error");
+   }   
+      
+   return true;
+}
+									/*}}}*/
+// File::Write - Write to the file					/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool File::Write(void *From,unsigned long Size)
+{
+   if (write(iFd,From,Size) != (signed)Size)
+   {
+      Flags |= Fail;
+      return _error->Errno("write","Write error");
+   }
+   
+   return true;
+}
+									/*}}}*/
+// File::Seek - Seek in the file					/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool File::Seek(unsigned long To)
+{
+   if (lseek(iFd,To,SEEK_SET) != (signed)To)
+   {
+      Flags |= Fail;
+      return _error->Error("Unable to seek to %u",To);
+   }
+   
+   return true;
+}
+									/*}}}*/
+// File::Size - Return the size of the file				/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+unsigned long File::Size()
+{
+   struct stat Buf;
+   if (fstat(iFd,&Buf) != 0)
+      return _error->Errno("fstat","Unable to determine the file size");
+   return Buf.st_size;
+}
+									/*}}}*/
+// File::Close - Close the file	if the close flag is set		/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool File::Close()
+{
+   bool Res = true;
+   if ((Flags & AutoClose) == AutoClose)
+      if (close(iFd) != 0)
+	 Res &= _error->Errno("close","Problem closing the file");
+      
+   if ((Flags & Fail) == Fail && (Flags & DelOnFail) == DelOnFail &&
+       FileName.empty() == false)
+      if (unlink(FileName.c_str()) != 0)
+	 Res &= _error->Warning("unlnk","Problem unlinking the file");
+   return Res;
+}
+									/*}}}*/