function ts() {
    local hires
    local format
    local rel
    local dif

    hires=0
    format='[%Y-%m-%d %H:%M:%S]'
    rel=0
    dif=0

    while [[ "${#}" -gt 0 ]]; do
        case "${1}" in
            -h)
                hires=1
                format='[%Y-%m-%d %H:%M:%.S]'
                ;;
            -r)
                rel=1
                ;;
            -d)
                dif=1
                ;;
            *%.S*|*%.s*)
                format="${1}"
                hires=1
                ;;
            *)
                format="${1}"
                ;;
        esac
        shift
    done

    if [[ "${dif}" = 1 ]]; then
        if [[ "${hires}" = 1 ]]; then
            perl -pe 'use POSIX strftime; use Time::HiRes gettimeofday; $| = 1; select((select(STDERR), $| = 1)[0]); ($s, $ms) = gettimeofday(); $p_s ||= $s; $p_ms ||= $ms; $d_s = $s - $p_s; $d_ms = $ms - $p_ms; $d = $d_s + $d_ms / 1000000.0; printf "%.6f ", $d; $p_s = $s; $p_ms = $ms'
        else
            perl -pe 'use POSIX strftime; $| = 1; select((select(STDERR), $| = 1)[0]); $s = time; $p ||= $s; $b = $s - $p; print "$b "; $p = $s'
        fi
    elif [[ "${rel}" = 1 ]]; then
        if [[ "${hires}" = 1 ]]; then
            perl -pe 'use POSIX strftime; use Time::HiRes gettimeofday; $| = 1; select((select(STDERR), $| = 1)[0]); ($s, $ms) = gettimeofday(); $p_s ||= $s; $p_ms ||= $ms; $d_s = $s - $p_s; $d_ms = $ms - $p_ms; $d = $d_s + $d_ms / 1000000.0; printf "%.6f ", $d'
        else
            perl -pe 'use POSIX strftime; $| = 1; select((select(STDERR), $| = 1)[0]); $s = time; $p ||= $s; $b = $s - $p; print "$b "'
        fi
    else
        if [[ "${hires}" = 1 ]]; then
            perl -pe 'use POSIX strftime; use Time::HiRes gettimeofday; $| = 1; select((select(STDERR), $| = 1)[0]); ($s, $ms) = gettimeofday(); $v = sprintf("%06i", $ms); $f = "'"${format}"'"; $f =~ s/\%\.([Ss])/%$1.$v/g ; print strftime "$f ", localtime($s)'
        else
            perl -pe 'use POSIX strftime; $| = 1; select((select(STDERR), $| = 1)[0]); $f = "'"${format}"'"; print strftime "$f ", localtime'
        fi
    fi
}

# vim: ft=bash