shell-error

#!/bin/sh -efu
### This file is covered by the GNU General Public License,
### which should be included with libshell as the file LICENSE.
### All copyright information are listed in the COPYING.

if [ -z "${__included_shell_error-}" ]; then
__included_shell_error=1

PROG="${PROG:-${0##*/}}"

message_syslog=
message_time=
message_time_format=
message()
{
	local arg= prefix=
	if [ -n "$message_syslog" ]; then
		[ ! -t 2 ] || arg=-s
		logger $arg -t "$PROG" "$*"
		return
	fi
	[ -z "$message_time" ] ||
		prefix="$(date +"${message_time_format:-[%Y-%m-%d %T]} " 2>/dev/null)" ||:
	printf %s\\n "${prefix}$PROG: $*" >&2
}

fatal()
{
	message "$@"
	exit 1
}

quiet="${quiet-}"
verbose="${verbose-}"
verbose()
{
	[ -n "$verbose" ] || return 0
	message "$@"
}

fi #__included_shell_error