Complex Bash log routine. May log to files and stdout. Supports messages stream from STDIN.

log

#!/bin/sh

log() {
    local _opt=''
    local _date="`date -R`"
    local _log_tag="`basename $0`"
    local _level='${LOG_LEVEL:-debug}'
    local _print=0
    local _log_path="${LOG_PATH:-/tmp}"
    local _log_facility="${LOG_FACILITY:-local1}"
    local _runtime="`date '+%Y-%m-%d-%H-%M-%S'`"

    while getopts ':f:l:p:t:o' _opt; do
        case "${_opt}" in
            f)
                _log_tag="${_log_tag}.${OPTARG}"
                ;;
            l)
                _level="${OPTARG}"
                ;;
            o)
                _print=1
                ;;
            p)
                _log_path="${OPTARG}"
                ;;
            t)
                _runtime="${OPTARG}"
                ;;
            *)
                ;;
        esac
    done
    shift shift $((${OPTIND}-1))
    local _rec="$1"

    if [[ "${_rec}" ]]; then
        # log message given
		if [[ "${_log_path}" == "syslog" ]]; then
			#statements
			logger -p "${_log_facility}.${_level}" -t "${_log_tag}" -i "${_rec}" >/dev/null 2>&1
			# Print message to STDOUT
			[[ ${_print} -gt 0 ]] && echo "${_date} `hostname` ${_log_tag}[$$]: ${_log_facility}.${_level} ${_rec}"
		elif [[ "${_log_path}" == '' ]]; then
			echo "${_date} `hostname` ${_log_tag}[$$]: ${_log_facility}.${_level} ${_rec}"
		else
			# create logs path
			[ ! -d "${_log_path}" ] && mkdir -p "${_log_path}"
			echo "${_date} `hostname` ${_log_tag}[$$]: ${_log_facility}.${_level} ${_rec}" >>"${_log_path}/${_runtime}.log"
			[[ ${_print} -gt 0 ]] && echo "${_date} `hostname` ${_log_tag}[$$]: ${_log_facility}.${_level} ${_rec}"
		fi
    else
        # log from STDIN
        while read _rec; do
            if [[ "${_log_path}" == "syslog" ]]; then
                #statements
                logger -p "${_log_facility}.${_level}" -t "${_log_tag}" -i "${_rec}" >/dev/null 2>&1
                [[ ${_print} -gt 0 ]] && echo "${_date} `hostname` ${_log_tag}[$$]: ${_log_facility}.${_level} ${_rec}"
            elif [[ "${_log_path}" == '' ]]; then
                echo "${_date} `hostname` ${_log_tag}[$$]: ${_log_facility}.${_level} ${_rec}"
            else
                # create logs path
                [ ! -d "${_log_path}" ] && mkdir -p "${_log_path}"
                echo "${_date} `hostname` ${_log_tag}[$$]: ${_log_facility}.${_level} ${_rec}" >> "${_log_path}/${_runtime}.log"
                [[ ${_print} -gt 0 ]] && echo "${_date} `hostname` ${_log_tag}[$$]: ${_log_facility}.${_level} ${_rec}"
            fi
        done
    fi
}