// -*- mode: cpp; mode: fold -*-
// Description /*{{{*/
-// $Id: fileutl.cc,v 1.17 1999/01/18 06:20:08 jgg Exp $
+// $Id: fileutl.cc,v 1.34 2000/01/17 07:11:49 jgg Exp $
/* ######################################################################
File Utilities
#include <apt-pkg/error.h>
#include <unistd.h>
+#include <fcntl.h>
#include <sys/stat.h>
-#include <sys/fcntl.h>
#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <errno.h>
/*}}}*/
// CopyFile - Buffered copy of a file /*{{{*/
// Buffered copy between fds
unsigned char *Buf = new unsigned char[64000];
- long Size;
- while ((Size = read(From.Fd(),Buf,64000)) > 0)
+ unsigned long Size = From.Size();
+ while (Size != 0)
{
- if (To.Write(Buf,Size) == false)
+ unsigned long ToRead = Size;
+ if (Size > 64000)
+ ToRead = 64000;
+
+ if (From.Read(Buf,ToRead) == false ||
+ To.Write(Buf,ToRead) == false)
{
delete [] Buf;
return false;
}
+
+ Size -= ToRead;
}
delete [] Buf;
// 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;
+ fl.l_type = F_WRLCK;
+ fl.l_whence = SEEK_SET;
+ fl.l_start = 0;
+ fl.l_len = 0;
if (fcntl(FD,F_SETLK,&fl) == -1)
{
+ if (errno == ENOLCK)
+ {
+ _error->Warning("Not using locking for nfs mounted lock file %s",File.c_str());
+ return true;
+ }
if (Errors == true)
_error->Errno("open","Could not get lock %s",File.c_str());
close(FD);
return string(File,0,Res);
}
/*}}}*/
+// flNoLink - If file is a symlink then deref it /*{{{*/
+// ---------------------------------------------------------------------
+/* If the name is not a link then the returned path is the input. */
+string flNoLink(string File)
+{
+ struct stat St;
+ if (lstat(File.c_str(),&St) != 0 || S_ISLNK(St.st_mode) == 0)
+ return File;
+ if (stat(File.c_str(),&St) != 0)
+ return File;
+
+ /* Loop resolving the link. There is no need to limit the number of
+ loops because the stat call above ensures that the symlink is not
+ circular */
+ char Buffer[1024];
+ string NFile = File;
+ while (1)
+ {
+ // Read the link
+ int Res;
+ if ((Res = readlink(NFile.c_str(),Buffer,sizeof(Buffer))) <= 0 ||
+ (unsigned)Res >= sizeof(Buffer))
+ return File;
+
+ // Append or replace the previous path
+ Buffer[Res] = 0;
+ if (Buffer[0] == '/')
+ NFile = Buffer;
+ else
+ NFile = flNotFile(NFile) + Buffer;
+
+ // See if we are done
+ if (lstat(NFile.c_str(),&St) != 0)
+ return File;
+ if (S_ISLNK(St.st_mode) == 0)
+ return NFile;
+ }
+}
+ /*}}}*/
// SetCloseExec - Set the close on exec flag /*{{{*/
// ---------------------------------------------------------------------
/* */
// WaitFd - Wait for a FD to become readable /*{{{*/
// ---------------------------------------------------------------------
/* This waits for a FD to become readable using select. It is usefull for
- applications making use of non-blocking sockets. */
-bool WaitFd(int Fd)
+ applications making use of non-blocking sockets. The timeout is
+ in seconds. */
+bool WaitFd(int Fd,bool write,unsigned long timeout)
{
fd_set Set;
+ struct timeval tv;
FD_ZERO(&Set);
FD_SET(Fd,&Set);
+ tv.tv_sec = timeout;
+ tv.tv_usec = 0;
+ if (write == true)
+ {
+ int Res;
+ do
+ {
+ Res = select(Fd+1,0,&Set,0,(timeout != 0?&tv:0));
+ }
+ while (Res < 0 && errno == EINTR);
+
+ if (Res <= 0)
+ return false;
+ }
+ else
+ {
+ int Res;
+ do
+ {
+ Res = select(Fd+1,&Set,0,0,(timeout != 0?&tv:0));
+ }
+ while (Res < 0 && errno == EINTR);
+
+ if (Res <= 0)
+ return false;
+ }
+
+ return true;
+}
+ /*}}}*/
+// ExecFork - Magical fork that sanitizes the context before execing /*{{{*/
+// ---------------------------------------------------------------------
+/* This is used if you want to cleanse the environment for the forked
+ child, it fixes up the important signals and nukes all of the fds,
+ otherwise acts like normal fork. */
+int ExecFork()
+{
+ // Fork off the process
+ pid_t Process = fork();
+ if (Process < 0)
+ {
+ cerr << "FATAL -> Failed to fork." << endl;
+ exit(100);
+ }
- if (select(Fd+1,&Set,0,0,0) <= 0)
- return false;
+ // Spawn the subprocess
+ if (Process == 0)
+ {
+ // Setup the signals
+ signal(SIGPIPE,SIG_DFL);
+ signal(SIGQUIT,SIG_DFL);
+ signal(SIGINT,SIG_DFL);
+ signal(SIGWINCH,SIG_DFL);
+ signal(SIGCONT,SIG_DFL);
+ signal(SIGTSTP,SIG_DFL);
+
+ // Close all of our FDs - just in case
+ for (int K = 3; K != 40; K++)
+ fcntl(K,F_SETFD,FD_CLOEXEC);
+ }
+
+ return Process;
+}
+ /*}}}*/
+// ExecWait - Fancy waitpid /*{{{*/
+// ---------------------------------------------------------------------
+/* Waits for the given sub process. If Reap is set the no errors are
+ generated. Otherwise a failed subprocess will generate a proper descriptive
+ message */
+bool ExecWait(int Pid,const char *Name,bool Reap)
+{
+ if (Pid <= 1)
+ return true;
+
+ // Wait and collect the error code
+ int Status;
+ while (waitpid(Pid,&Status,0) != Pid)
+ {
+ if (errno == EINTR)
+ continue;
+
+ if (Reap == true)
+ return false;
+
+ return _error->Error("Waited, for %s but it wasn't there",Name);
+ }
+
+ // Check for an error code.
+ if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0)
+ {
+ if (Reap == true)
+ return false;
+ if (WIFSIGNALED(Status) != 0 && WTERMSIG(Status) == SIGSEGV)
+ return _error->Error("Sub-process %s recieved a segmentation fault.",Name);
+
+ if (WIFEXITED(Status) != 0)
+ return _error->Error("Sub-process %s returned an error code (%u)",Name,WEXITSTATUS(Status));
+
+ return _error->Error("Sub-process %s exited unexpectedly",Name);
+ }
+
return true;
}
/*}}}*/
-// FileFd::FileFd - Open a file /*{{{*/
+// FileFd::Open - Open a file /*{{{*/
// ---------------------------------------------------------------------
/* The most commonly used open mode combinations are given with Mode */
-FileFd::FileFd(string FileName,OpenMode Mode, unsigned long Perms)
+bool FileFd::Open(string FileName,OpenMode Mode, unsigned long Perms)
{
+ Close();
Flags = AutoClose;
switch (Mode)
{
case WriteEmpty:
{
struct stat Buf;
- if (stat(FileName.c_str(),&Buf) == 0 && S_ISLNK(Buf.st_mode))
+ if (lstat(FileName.c_str(),&Buf) == 0 && S_ISLNK(Buf.st_mode))
unlink(FileName.c_str());
iFd = open(FileName.c_str(),O_RDWR | O_CREAT | O_TRUNC,Perms);
break;
}
if (iFd < 0)
- _error->Errno("open","Could not open file %s",FileName.c_str());
- else
- {
- this->FileName = FileName;
- SetCloseExec(iFd,true);
- }
+ return _error->Errno("open","Could not open file %s",FileName.c_str());
+
+ this->FileName = FileName;
+ SetCloseExec(iFd,true);
+ return true;
}
/*}}}*/
// FileFd::~File - Closes the file /*{{{*/
/*}}}*/
// FileFd::Read - Read a bit of the file /*{{{*/
// ---------------------------------------------------------------------
-/* */
-bool FileFd::Read(void *To,unsigned long Size)
+/* We are carefull to handle interruption by a signal while reading
+ gracefully. */
+bool FileFd::Read(void *To,unsigned long Size,bool AllowEof)
{
- if (read(iFd,To,Size) != (signed)Size)
+ int Res;
+ errno = 0;
+ do
{
- Flags |= Fail;
- return _error->Errno("read","Read error");
- }
+ Res = read(iFd,To,Size);
+ if (Res < 0 && errno == EINTR)
+ continue;
+ if (Res < 0)
+ {
+ Flags |= Fail;
+ return _error->Errno("read","Read error");
+ }
- return true;
+ To = (char *)To + Res;
+ Size -= Res;
+ }
+ while (Res > 0 && Size > 0);
+
+ if (Size == 0)
+ return true;
+
+ // Eof handling
+ if (AllowEof == true)
+ {
+ Flags |= HitEof;
+ return true;
+ }
+
+ Flags |= Fail;
+ return _error->Error("read, still have %u to read but none left",Size);
}
/*}}}*/
// FileFd::Write - Write to the file /*{{{*/
/* */
bool FileFd::Write(const void *From,unsigned long Size)
{
- if (write(iFd,From,Size) != (signed)Size)
+ int Res;
+ errno = 0;
+ do
{
- Flags |= Fail;
- return _error->Errno("write","Write error");
+ Res = write(iFd,From,Size);
+ if (Res < 0 && errno == EINTR)
+ continue;
+ if (Res < 0)
+ {
+ Flags |= Fail;
+ return _error->Errno("write","Write error");
+ }
+
+ From = (char *)From + Res;
+ Size -= Res;
}
+ while (Res > 0 && Size > 0);
- return true;
+ if (Size == 0)
+ return true;
+
+ Flags |= Fail;
+ return _error->Error("write, still have %u to write but couldn't",Size);
}
/*}}}*/
// FileFd::Seek - Seek in the file /*{{{*/
return _error->Error("Unable to seek to %u",To);
}
+ return true;
+}
+ /*}}}*/
+// FileFd::Skip - Seek in the file /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool FileFd::Skip(unsigned long Over)
+{
+ if (lseek(iFd,Over,SEEK_CUR) < 0)
+ {
+ Flags |= Fail;
+ return _error->Error("Unable to seek ahead %u",Over);
+ }
+
+ return true;
+}
+ /*}}}*/
+// FileFd::Truncate - Truncate the file /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool FileFd::Truncate(unsigned long To)
+{
+ if (ftruncate(iFd,To) != 0)
+ {
+ Flags |= Fail;
+ return _error->Error("Unable to truncate to %u",To);
+ }
+
return true;
}
/*}}}*/
projects / apt.git / blobdiff