centos man page for dl

DL(3)                                                        Library Functions Manual                                                        DL(3)

NAME
       DL - generate logging messages in C and C++ using a debugger

SYNOPSIS
       #include <DL.h>

       DL(format,...)

       DLG(guard,format,...)

       DLH(handler,format,...)

       DLP(param,format,...)

       DLGH(guard,handler,format,...)

       DLHP(handler,param,format,...)

       DLGHP(guard,handler,param,format,...)

DESCRIPTION
       The  DL  macro  is  used  to print logging or debugging messages using a debugger. The nana(1) command generates a set of debugger commands
       which are then sourced into gdb(1) to implement the logging. If you don't run the executable under gdb(1) then no tracing will occur.   The
       arguments are:

       format,... - a printf(3) style argument list containing the message

       guard - print only if the guard is true.

       handler - the code that does the printing. Default: fprintf

       param - a parameter to be passed off to the handler. Default: stdout

       See nana.info for details on configuring the behaviour.

SEE ALSO
       nana-clg(1), nana(1), nana(3), I(3), DI(3), L(3), DL(3), Q(3) and nana.info.

       The nana.info file is the primary documentation for this library.

AUTHOR
       Phil Maker <pjm@gnu.org>

                                                                                                                                             DL(3)