FBB::IFdStreambuf(3bobcat)
File Descriptor Input Stream Buffer
(libbobcat-dev_4.08.03-x.tar.gz)
2005-2018
NAME
FBB::IFdStreambuf - Input stream buffer initialized by a file descriptor
SYNOPSIS
#include <bobcat/ifdstreambuf>
Linking option: -lbobcat
DESCRIPTION
FBB::IFdStreambuf objects may be used as a std::streambuf of
std::istream objects to allow extractions from a file descriptor.
File descriptors are not defined within the context of C++,
but they can be used on operating systems that support the concept. Realize
that using file descriptors introduces operating system dependencies.
NAMESPACE
FBB
All constructors, members, operators and manipulators, mentioned in this
man-page, are defined in the namespace FBB.
INHERITS FROM
std::streambuf
ENUMERATION
The public enumeration Mode defined in the class FBB::IFdStreamBuf
has the following values:
- CLOSE_FD, indicating that the file descriptor used by the object
must be closed;
- KEEP_FD (the default) indicating that the file descriptor used by
the object must not be closed.
CONSTRUCTORS
- IFdStreambuf():
This constructor initializes the streambuf, without associating it to
a file descriptor, and without using buffering. The member open() can be
used subsequently to associate the object with a file descriptor and
optionally a buffer size. When the object is destroyed or if the mode-less
overloaded version of the open member is called, the file descriptor will
not be closed.
- IFdStreambuf(Mode mode):
This constructor initializes the streambuf, without associating it to
a file descriptor, and without using buffering. The member open() can be
used subsequently to associate the object with a file descriptor and
optionally a buffer size. When the object is destroyed or if the mode-less
overloaded version of the open member is called, the Mode argument
determines whether the file descriptor will be closed or will remain open.
- IFdStreambuf(int fd, size_t n = 1):
This constructor initializes the streambuf, associating it to file
descriptor fd, and an optional unget buffer size (by default having size
1). When the object is destroyed or if the mode-less overloaded version of
the open member is called, the file descriptor will not be closed.
- IFdStreambuf(int fd, Mode mode, size_t n = 1):
This constructor initializes the streambuf, associating it to file
descriptor fd, and an optional unget buffer size (by default having size
1). When the object is destroyed or if the mode-less
overloaded version of the open member is called, the Mode argument
determines whether the file descriptor will be closed or will remain open.
There is no copy constructor.
MEMBER FUNCTIONS
All members of std::streambuf are
available, as FBB::IFdStreambuf inherits from this class. Some of the
std::streambuf's member are overridden by FBB::IFdStreambuf, see
below.
- void close():
The file descriptor used by the IFdStreambuf is closed,
irrespective of the Mode that was specified when the IFdStreambuf
object was constructed. Following close the IFdStreambuf object can
no longer be used until one of its open members has been called.
- int fd() const:
The file descriptor used by the IFdStreambuf object is returned.
If the OFdStreambuf is not associated with a file descriptor -1 is
returned.
- void open(int xfd, size_t n = 1):
The streambuf is (re)initialized, using file descriptor fd, and an
optional unget buffer size (by default having size 1). When called repeatedly,
the Mode specification used whem the object was constructed determines
whether the file descriptor will be closed or will remain open.
- void open(int xfd, Mode mode, size_t n = 1):
The streambuf is (re)initialized, using file descriptor fd, a file
descriptor closing parameter and an optional unget buffer size (by default
having size 1). Depending on the Mode argument the object's currently used
file descriptor will be closed or will remain open when the IFdStreambuf
object is destroyed.
Note that there is no overloaded assignment operator available for this
class.
EXAMPLE
To do
FILES
bobcat/ifdstreambuf - defines the class interface
SEE ALSO
bobcat(7), ifdstream(3bobcat), ofdstreambuf(3bobcat),
std::streambuf
BUGS
The member xsgetn(char *dest, std::streamsize n) will set
istream::good() to false when fewer bytes than n were read using
istream::read(). Also see xsgetn's description.
Note that by default the provided file descriptors remain open. The
complementary class ofdstreambuf(3bobcat) closes the file descriptor
by default. This inconsistency was deliberately accepted to keep the classes
interfaces backward compatible.
DISTRIBUTION FILES
- bobcat_4.08.03-x.dsc: detached signature;
- bobcat_4.08.03-x.tar.gz: source archive;
- bobcat_4.08.03-x_i386.changes: change log;
- libbobcat1_4.08.03-x_*.deb: debian package holding the
libraries;
- libbobcat1-dev_4.08.03-x_*.deb: debian package holding the
libraries, headers and manual pages;
- http://sourceforge.net/projects/bobcat: public archive location;
BOBCAT
Bobcat is an acronym of `Brokken's Own Base Classes And Templates'.
COPYRIGHT
This is free software, distributed under the terms of the
GNU General Public License (GPL).
AUTHOR
Frank B. Brokken (f.b.brokken@rug.nl).