el_enable_output

NAME

el_enable_output - enable one or more outputs. el_disable_output - disable one or more outputs.

SYNOPSIS

#include <embedlog.h>

int el_enable_output(enum el_output output)
int el_disable_output(enum el_output output)

int el_oenable_output(struct el *el, enum el_output output);
int el_odisable_output(struct el *el, enum el_output output);

DESCRIPTION

Set to what outputs logs will be printed with any of the printing function. User can enable as many outputs as he desires - it can be all inputs or even none (if one wants to surpress logging for some time). To enable multiple outputs join values with or operator ( | ).

Currently following outputs can be enabled.

EL_OUT_STDERR

Messages will be printed to standard error output

EL_OUT_STDOUT

Messages will be printed to standard output

EL_OUT_SYSLOG

Messages will be sent to syslog facility. This requires system with implemented POSIX.1-2001 and any syslog daemon

EL_OUT_FILE

Messages will be printed to file. To work user should set output file with EL_FPATH. Log rotation can be configured with EL_FROTATE_NUMBER and EL_FROTATE_SIZE options.

EL_OUT_NET

Messages shall be printed to external server. This requires BSD Sockets to be enabled on the clients system, and listening server. (TODO Not implemented yet)

EL_OUT_TTY

Prints messages directly to configured serial console. Apart from setting this, user should also configure device and speed with EL_TTY_DEV.

EL_OUT_ALL

Enables all supported outputs at once

EL_OUT_NONE

Disables every output - logs won't be printed at all

EL_OUT_CUSTOM

Enables custom function to be called on log print. Pointer to custom function needs to be set with EL_CUSTOM_PUTS option.

Many of the outputs can be configured for special needs, and some of them need mandatory configuration. For information about output configuration see proper option description

With this function you can enable or disable outputs without altering any previously set outputs.

EXAMPLES

/* Enable stdout outout (default stderr, is still enabled) */
el_enable_output(EL_OUT, EL_OUT_STDOUT);

/* Add file and network logging retaining stdout and stderr */
el_enable_output(EL_OUT, EL_OUT_NET | EL_OUT_FILE);

/* Remove only stderr from the outputs, all other will be rtained */
el_disable_output(EL_OUT, EL_OUT_STDERR);

/* Now disable net and file, leaving only stdout as result */
el_disable_output(EL_OUT, EL_OUT_NET | EL_OUT_FILE);

RETURN VALUE

0 on succes, or -1 and set errno on failure.

ERRORS

ERRORS

EINVAL

Specified output is invalid

ENODEV

Specified output is not implemented on current system (support was not compiled into library)