FBB::IFdStreambuf - Input stream buffer initialized by a file
descriptor
#include <bobcat/ifdstreambuf>
Linking option: -lbobcat
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.
FBB
All constructors, members, operators and manipulators, mentioned in this
man-page, are defined in the namespace FBB.
The public enumeration Mode defined in the class
FBB::IFdStreamBuf has the following values:
- o
- CLOSE_FD, indicating that the file descriptor used by the object
must be closed;
- o
- KEEP_FD (the default) indicating that the file descriptor used by
the object must not be closed.
- o
- 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.
- o
- 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.
- o
- 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.
- o
- 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.
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.
- o
- 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.
- o
- 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.
- o
- 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.
- o
- 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.
bobcat/ifdstreambuf - defines the class interface
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.
- o
- bobcat_4.08.06-x.dsc: detached signature;
- o
- bobcat_4.08.06-x.tar.gz: source archive;
- o
- bobcat_4.08.06-x_i386.changes: change log;
- o
- libbobcat1_4.08.06-x_*.deb: debian package holding the
libraries;
- o
- libbobcat1-dev_4.08.06-x_*.deb: debian package holding the
libraries, headers and manual pages;
- o
- http://sourceforge.net/projects/bobcat: public archive location;
Bobcat is an acronym of `Brokken’s Own Base Classes And
Templates’.
This is free software, distributed under the terms of the GNU
General Public License (GPL).
Frank B. Brokken (f.b.brokken@rug.nl).