---
name: "L"
section: "3"
platform: "linux"
package: "nana"
version: "2.5-12+deb7u1"
release: "Debian 7 (Wheezy)"
platforms: ["linux"]
url: "https://new.carta.tech/L"
---

# L(3)

generate logging messages in C and C++.

## NAME

L - generate logging messages in C and C++.

## SYNOPSIS

\#include \<L.h\>

L(format,...)

LG(guard,format,...)

LH(handler,format,...)

LP(param,format,...)

LGH(guard,handler,format,...)

LHP(handler,param,format,...)

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

## DESCRIPTION

The L macro is used to print logging or debugging messages.

format,... - a [printf(3)](/printf/3.md) style argument list containing the message

guard - print only if the guard is true.

handler - the code that does the printing, e.g. support is provided for sending log messages to a circular buffer.

param - a parameter to be passed off to the handler, e.g. a file descriptor.

See nana.info for details on configuring the behaviour. You also need to include the nana library by using -lnana if you use the default setup.

## SEE ALSO

[nana-clg(1)](/nana-clg/1.md), [nana(1)](/nana/1.md), [nana(3)](/nana/3.md), [I(3)](/I/3.md), [DI(3)](/DI/3.md), [L(3)](/L/3.md), [DL(3)](/DL/3.md), [Q(3)](/Q/3.md) and nana.info.

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

## AUTHOR

Phil Maker \<pjm@gnu.org\>