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// -*- mode: cpp; mode: fold -*-
// Description /*{{{*/
// $Id: fileutl.cc,v 1.2 1998/07/04 05:57:41 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 <pkglib/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;
}
/*}}}*/