Provided by: libbobcat-dev_4.08.02-2build1_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.
o UTCTIMESTAMPS:
Log-messages will have timestamps showing the UTC time 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.
Copy and move constructors are not available.
MEMBER FUNCTIONS
All members of std::streambuf are available, as FBB::LogBuffer inherits from this class.
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 void setActive(bool active):
The member function (de)activates logging. The argument true activates logging, the argument false
deactivates it.
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 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.
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.
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, FBB::TIMESTAMPS);
ostream log(&buffer);
log << "This message is written to cout" << nl <<
setw(16) << ’ ’ << "occupying multiple lines\n";
}
FILES
bobcat/logbuffer - defines the class interface
SEE ALSO
bobcat(7), log(3bobcat)
BUGS
None Reported.
DISTRIBUTION FILES
o bobcat_4.08.02-x.dsc: detached signature;
o bobcat_4.08.02-x.tar.gz: source archive;
o bobcat_4.08.02-x_i386.changes: change log;
o libbobcat1_4.08.02-x_*.deb: debian package holding the libraries;
o libbobcat1-dev_4.08.02-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).