--- /dev/null
+// -*- mode: cpp; mode: fold -*-
+// Description /*{{{*/
+// $Id: fileutl.cc,v 1.5 1999/10/24 06:53:12 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 /*{{{*/
+#ifdef __GNUG__
+#pragma implementation "dsync/fileutl.h"
+#endif
+#include <dsync/fileutl.h>
+#include <dsync/error.h>
+
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/fcntl.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <signal.h>
+#include <wait.h>
+#include <errno.h>
+#include <iostream>
+
+using namespace std;
+ /*}}}*/
+
+// CopyFile - Buffered copy of a file /*{{{*/
+// ---------------------------------------------------------------------
+/* The caller is expected to set things so that failure causes erasure */
+bool CopyFile(FileFd &From,FileFd &To)
+{
+ if (From.IsOpen() == false || To.IsOpen() == false)
+ return false;
+
+ // Buffered copy between fds
+ unsigned char *Buf = new unsigned char[64000];
+ unsigned long Size = From.Size();
+ while (Size != 0)
+ {
+ 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;
+ 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 = 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 -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)-2) == 0)
+ return "/";
+ unsigned int Len = strlen(S);
+ S[Len] = '/';
+ S[Len+1] = 0;
+ return S;
+}
+ /*}}}*/
+// flNotDir - Strip the directory from the filename /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+string flNotDir(string File)
+{
+ string::size_type Res = File.rfind('/');
+ if (Res == string::npos)
+ return File;
+ Res++;
+ return string(File,Res,Res - File.length());
+}
+ /*}}}*/
+// flNotFile - Strip the file from the directory name /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+string flNotFile(string File)
+{
+ string::size_type Res = File.rfind('/');
+ if (Res == string::npos)
+ return File;
+ Res++;
+ 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 /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+void SetCloseExec(int Fd,bool Close)
+{
+ if (fcntl(Fd,F_SETFD,(Close == false)?0:FD_CLOEXEC) != 0)
+ {
+ cerr << "FATAL -> Could not set close on exec " << strerror(errno) << endl;
+ exit(100);
+ }
+}
+ /*}}}*/
+// SetNonBlock - Set the nonblocking flag /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+void SetNonBlock(int Fd,bool Block)
+{
+ int Flags = fcntl(Fd,F_GETFL) & (~O_NONBLOCK);
+ if (fcntl(Fd,F_SETFL,Flags | ((Block == false)?0:O_NONBLOCK)) != 0)
+ {
+ cerr << "FATAL -> Could not set non-blocking flag " << strerror(errno) << endl;
+ exit(100);
+ }
+}
+ /*}}}*/
+// 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. 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);
+ }
+
+ // 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::Open - Open a file /*{{{*/
+// ---------------------------------------------------------------------
+/* The most commonly used open mode combinations are given with Mode */
+bool FileFd::Open(string FileName,OpenMode Mode, unsigned long Perms)
+{
+ Close();
+ Flags = AutoClose;
+ switch (Mode)
+ {
+ case ReadOnly:
+ iFd = open(FileName.c_str(),O_RDONLY);
+ break;
+
+ case WriteEmpty:
+ {
+ struct stat Buf;
+ if (stat(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;
+ }
+
+ case WriteExists:
+ iFd = open(FileName.c_str(),O_RDWR);
+ break;
+
+ case WriteAny:
+ iFd = open(FileName.c_str(),O_RDWR | O_CREAT,Perms);
+ break;
+ }
+
+ if (iFd < 0)
+ 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 /*{{{*/
+// ---------------------------------------------------------------------
+/* If the proper modes are selected then we close the Fd and possibly
+ unlink the file on error. */
+FileFd::~FileFd()
+{
+ Close();
+}
+ /*}}}*/
+// FileFd::Read - Read a bit of the file /*{{{*/
+// ---------------------------------------------------------------------
+/* We are carefull to handle interruption by a signal while reading
+ gracefully. */
+bool FileFd::Read(void *To,unsigned long Size,bool AllowEof)
+{
+ int Res;
+ errno = 0;
+ do
+ {
+ Res = read(iFd,To,Size);
+ if (Res < 0 && errno == EINTR)
+ continue;
+ if (Res < 0)
+ {
+ Flags |= Fail;
+ return _error->Errno("read","Read error");
+ }
+
+ 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)
+{
+ int Res;
+ errno = 0;
+ do
+ {
+ 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);
+
+ 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 /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool FileFd::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;
+}
+ /*}}}*/
+// 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;
+}
+ /*}}}*/
+// FileFd::Tell - Current seek position /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+unsigned long FileFd::Tell()
+{
+ off_t Res = lseek(iFd,0,SEEK_CUR);
+ if (Res == (off_t)-1)
+ _error->Errno("lseek","Failed to determine the current file position");
+ return Res;
+}
+ /*}}}*/
+// FileFd::Size - Return the size of the file /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+unsigned long FileFd::Size()
+{
+ struct stat Buf;
+ if (fstat(iFd,&Buf) != 0)
+ return _error->Errno("fstat","Unable to determine the file size");
+ return Buf.st_size;
+}
+ /*}}}*/
+// FileFd::Close - Close the file if the close flag is set /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool FileFd::Close()
+{
+ bool Res = true;
+ if ((Flags & AutoClose) == AutoClose)
+ if (iFd >= 0 && close(iFd) != 0)
+ Res &= _error->Errno("close","Problem closing the file");
+ iFd = -1;
+
+ 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;
+}
+ /*}}}*/
projects / dak.git / blobdiff