Ubuntu Manpage: FBB::IFdBuf - Input stream buffer initialized by a file descriptor

Provided by: libbobcat-dev_5.11.01-1_amd64

NAME

       FBB::IFdBuf - Input stream buffer initialized by a file descriptor

SYNOPSIS

       #include <bobcat/ifdbuf>
       Linking option: -lbobcat

DESCRIPTION

       FBB::IFdBuf  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:

       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.

CONSTRUCTORS

o IFdBuf():
This constructor initializes the streambuf, without associating it to a file
descriptor, and without using buffering. The member reset 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 reset member
is called, the file descriptor is not closed.

o IFdBuf(Mode mode):
This constructor initializes the streambuf, without associating it to a file
descriptor, and without using buffering. The member reset 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 member reset
is called, the Mode argument determines whether the file descriptor will be closed
or will remain open.

o IFdBuf(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 member reset is called, the
file descriptor is not closed.

o IFdBuf(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 reset member is called, the
Mode argument determines whether the file descriptor will be closed or will remain
open.

Copy and move constructors (and assignment operators) are not available.

MEMBER FUNCTIONS

       All members of std::streambuf are available, as FBB::IFdBuf inherits from this class.

       o      void close():
              The file descriptor used by the IFdBuf is closed, irrespective of the Mode that was
              specified when the IFdBuf object was constructed. Following close the IFdBuf object
              can no longer be used until one of its reset members has been called.

       o      int fd() const:
              The  file  descriptor  used by the IFdBuf object is returned.  If the OFdBuf is not
              associated with a file descriptor -1 is returned.

       o      void reset(int fd, 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 reset(int fd, 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 IFdBuf object is destroyed.

EXAMPLE

       #include <unistd.h>

       #include <istream>
       #include <iostream>

       #include <bobcat/ifdbuf>

       using namespace std;
       using namespace FBB;

       int main(int argc, char **argv)
       {
                                  // define a streambuf of 20 or argv[1] characters
           IFdBuf buf{ STDIN_FILENO, argc == 1 ? 20 : stoul(argv[1]) };

           istream in{ &buf };

           cout << in.rdbuf();
       }

FILES

       bobcat/ifdbuf - defines the class interface

BUGS

       The member xsgetn(char *dest, std::streamsize n) sets 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
       ofdbuf(3bobcat) by default closes the file descriptor.

BOBCAT PROJECT FILES

       o      https://fbb-git.gitlab.io/bobcat/: gitlab project page;

       o      bobcat_5.11.01-x.dsc: detached signature;

       o      bobcat_5.11.01-x.tar.gz: source archive;

       o      bobcat_5.11.01-x_i386.changes: change log;

       o      libbobcat1_5.11.01-x_*.deb: debian package containing the libraries;

       o      libbobcat1-dev_5.11.01-x_*.deb: debian package containing  the  libraries,  headers
              and manual pages;

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).