Provided by: libbobcat-dev_3.19.01-1ubuntu1_amd64 
NAME
FBB::LogBuffer - std::streambuf handling log messages
SYNOPSIS
#include <bobcat/logbuffer>
Linking option: -lbobcat
DESCRIPTION
FBB::LogBuffer is a class derived from std::streambuf handling log messages. The stream to
log to, timestamps and log-levels can be configured both at construction time and beyond.
The FBB::LogBuffer may be used to initialize a std::ostream.
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 enumeration TimeStamps is defined in the namespace FBB to be used when initializing
FBB::LogBuffer objects. It has the following values:
o NOTIMESTAMPS:
Log-messages will not have timestamps prepended to them.
o TIMESTAMPS:
Log-messages will have timestamps prepended to them.
CONSTRUCTORS
o LogBuffer(TimeStamps timestamps = TIMESTAMPS, bool active = true, char const *delim
= " "):
This constructor constructs an FBB::LogBuffer object writing its log-messages to
std::cerr. If the active parameter is initialized to false no messages will be
logged until the buffer’s activity is switched on (see setActive() below). The
parameter delim is inserted immediately beyond the time stamp. If a delimiter is
inappropriate, an empty string or a 0-pointer may be specified. When stamps ==
FBB::NOTIMESTAMPS delim is ignored. A time stamp consists of the month, the day
number of the month and the (local) time of the current message, as usually
appearing in messages in /var/log files. E.g., Aug 5 13:52:23.
o LogBuffer(std::ostream &stream, TimeStamps timestamps = TIMESTAMPS, bool active =
true, char const *delim = " "):
This constructor constructs an FBB::LogBuffer object writing its log-messages to
the stream used to initialize its stream parameter. If the active parameter is
initialized to false no messages will be logged until the buffer’s activity is
switched on (see setActive() below). The parameter delim is inserted immediately
beyond the time stamp. If a delimiter is inappropriate, an empty string or a
0-pointer may be specified. When stamps == FBB::NOTIMESTAMPS delim is ignored. A
time stamp consists of the month, the day number of the month and the (local) time
of the current message, as usually appearing in messages in /var/log files. E.g.,
Aug 5 13:52:23. The copy constructor is not available.
MEMBER FUNCTIONS
All members of std::streambuf are available, as FBB::LogBuffer inherits from this class.
o void setStream(std::ostream &stream):
This member may be used to switch the stream to log to. It is the responsibility of
the programmer to ensure that the external stream remains available for as long as
log-messages are inserted into it.
o int overflow(int c):
This member overrides the std::streambuf member. It is called by std::ostream
objects using OFdStreambuf. It calls sync(), an then it puts the next available
character into the buffer. It returns the inserted character.
o int sync():
This member overrides the std::streambuf member. It writes the buffer to the device
associated with the file descriptor, and returns 0.
o void setStream(bool active):
The member function (de)activates logging. The argument true activates logging, the
argument false deactivates it.
o void settimestamp(FBB::TimeStamps timestamps, char const *delim = " "):
The member function (de)activates time stamp prepending. Use the value
FBB::TIMESTAMPS to prepend time stamps, FBB::NOTIMESTAMPS suppresses time stamps.
A time stamp consists of the month, the day number of the month and the (local)
time of the current message, as usually appearing in messages in /var/log files.
E.g., Aug 5 13:52:23. The parameter delim is inserted immediately beyond the time
stamp. If a delimiter is inappropriate, an empty string or a 0-pointer may be
specified. When stamps == FBB::NOTIMESTAMPS delim is ignored.
o void setEmpty(bool empty):
This member may be called to ensure that a timestamp is inserted before the next
insertion. It is called as setEmpty(true) when a newline character (\n) is
inserted, ensuring that another timestamp is prepended before the next insertion.
PROTECTED MEMBER FUNCTION
The member listed in this section implements the tasks of the comparably named virtual
function in the class’s private interface. This separates the redefinable interface from
the user-interface. The class LogBuffer can, in accordance with Liskov’s Substitution
Principle, be used as a std:streambuf; but it also offers a facility for classes deriving
from LogBuffer. This facility is listed here.
o int pSync():
The contents of the LogBuffer’s internal buffer is flushed.
EXAMPLE
#include <iostream>
#include <iomanip>
#include <bobcat/log>
using namespace std;
using namespace FBB;
int main()
{
LogBuffer buffer(cout);
ostream log(&buffer);
log << "This message is written to cout" << nl <<
setw(16) << ’ ’ << "occupying multiple lines\n";
return 0;
}
FILES
bobcat/logbuffer - defines the class interface
SEE ALSO
bobcat(7), log(3bobcat)
BUGS
None Reported.
DISTRIBUTION FILES
o bobcat_3.19.01-x.dsc: detached signature;
o bobcat_3.19.01-x.tar.gz: source archive;
o bobcat_3.19.01-x_i386.changes: change log;
o libbobcat1_3.19.01-x_*.deb: debian package holding the libraries;
o libbobcat1-dev_3.19.01-x_*.deb: debian package holding the libraries, headers and
manual pages;
o 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).