lsb-base for Debian
-------------------

The Debian lsb-base package provides a series of logging functions to
permit simplified logging of init script actions.  These functions are
specific to Debian and (in some cases) other derived distributions.

  - log_daemon_msg "Starting/stopping long daemon name" "daemond"

    Log starting/stopping of daemons.  On Debian, outputs:

    "Starting/stopping long daemon name: daemond"

    and leaves the cursor at the end of the line.

  - log_progress_msg "daemon2d"

    Log startup of a second daemon (e.g. sysklogd, nfs init scripts).
    On Debian, outputs " daemon2d" and leaves the cursor at the EOL.

  - log_end_msg 0/1

    Log successful startup.  On Debian, outputs "." followed by newline.
    A non-zero code may also be specified, which indicates failure;
    currently implemented as outputting "failed!" (in red on a color
    TTY) followed by newline.

    Unsucessful startup will cause the specified failure code to be
    returned by this function; unless trapped, this may end your init
    script depending on whether or not set -e is used.

  - log_action_msg "Setting VARIABLE to VALUE"

    Log an atomic action by your init script.  Typically, this is the
    setting of a kernel variable, but it might be something else that is
    not expected to take any time (or fail).

    On Debian, a trailing period will be added to the message,
    followed by a newline.

  - log_action_begin_msg "Configuring network interfaces"

    Log the start of an action that is expected to take some time.  On
    Debian, an elipsis (...) will follow the message, and the cursor will
    stay at EOL.

  - log_action_cont_msg "flushing ARP cache"

    Log an action as part of a process started by log_action_start_msg().
    On Debian, this message will receive a trailing elipsis, and the cursor
    will stay at EOL.

  - log_action_end_msg {0|1} ["message"]

    Log the end of the action started by log_action_start_msg().  If one
    argument is supplied, either "done." (0) or "failed." (1) will be output,
    followed by a newline.  If a second argument is supplied, the message
    will appear as follows:

    "done (your message here)." --- if first argument is 0
    "failed (your message here)." --- if first argument is 1

    This argument must be quoted, or otherwise only the first word will
    be output.

    On color TTYs, the failure messages will be red.

    Note that unlike log_end_msg(), this function does not return the
    first argument as its exit code.

A deprecated function, log_start_msg, is also provided for
compatibility with a few older packages and a derived distribution.
This may eventually disappear.

To use these functions, source /lib/lsb/init-functions at the
beginning of your (Bourne sh or compatible) init script.

Please depend on lsb-base (>= 3.0-6) to ensure all of these
functions are available for your init scripts.

LSB LOGGING FUNCTIONS

This package also includes the LSB-specified logging functions:

log_success_msg message
log_failure_msg message
log_warning_msg message

These functions *do not* comply with Debian policy and should only be used
by LSB packages.

OTHER LSB FUNCTIONALITY

start_daemon [-f] [-n nicelevel] [-p pidfile] pathname [args...]
  Start "pathname" as a daemon.  We call Debian's start-stop-daemon to
  implement this functionality.

killproc [-p pidfile] pathname [signal]
  Stops "pathname" (using "pidfile", if specified, to find the process
  ID).  This is implemented using start-stop-daemon as well.

pidofproc [-p pidfile] pathname
  Find the process ID of pathname.  If the pidfile is specified, we use the
  first space-delimited word; otherwise, /bin/pidof is used from the
  sysvinit package, if available.

For full documentation, please refer to:

http://refspecs.freestandards.org/LSB_3.1.0/LSB-Core-generic/LSB-Core-generic/iniscrptfunc.html

Note: Debian packages probably should use start-stop-daemon directly;
however, these functions may be useful in porting init scripts from
other distributions.  Also, if you are developing software for wider
use, you should not expect these functions to be implemented
identically on other LSB-conforming distributions; the only guaranteed
behaviors are those in the specification above.

CUSTOMIZING LOGGING OUTPUT

If it exists, /etc/lsb-base-logging.sh will be sourced by
/lib/lsb/init-functions.  You may override any of the log_* functions
in this file.  The intent is for this file to be supplied as a
conffile by derived distributions wishing to log init script events in
a different way; this may also be useful on systems where the console
log is not visible during startup.

If supplied, this script fragment should be compatible with any Debian
/bin/sh, as init scripts sourcing this file may be running under any
Bourne-style shell permitted by Debian policy (i.e. not just bash).

"Fancy output" can be overriden by setting FANCYTTY=0 in this file.

From lsb-base 3.2-14, you can use the following hook functions which
are called by the appropriate functions, instead of supplying your own
logging functions:

log_daemon_msg_pre
log_daemon_msg_post
log_end_msg_pre
log_end_msg_post
log_action_end_msg_pre
log_action_end_msg_post

Each function receives all of the arguments sent to the parent
function; the "pre" functions operate before any output, while the
"post" functions operate after the output is produced.

 -- Chris Lawrence <lawrencc@debian.org>, Mon, 14 Jul 2008 11:34:48 -0500