simplepanel.sh on dash

#! /bin/dash
#
# simplepanel.sh
#
# Simple panel script for bspwm with lemonbar
# inspired by limepanel.
#

# Set size and position

SP_WIDTH=
SP_HEIGHT=28
SP_POSITION=

# Set fonts

SP_FONT_1="xos4Terminus:pixelsize=18"
SP_OFFSET_1=-6

SP_FONT_2="Symbola:pixelsize=30"
SP_OFFSET_2=2

# Set colors

SP_BG_COLOR="#FFEFF0F1"
SP_BG_COLOR_1="#FF3DAEE9"
SP_FG_COLOR="#FF101010"
SP_FG_COLOR_1="grey"
SP_FG_COLOR_2="#FF5C616C"

# Set lemonbar format codes

BC="%{B-}"
BC1="%{B$SP_BG_COLOR_1}"
FC="%{F-}"
FC1="%{F$SP_FG_COLOR_1}"
FC2="%{F$SP_FG_COLOR_2}"
SEPARATOR="$FC1│$FC"
CENTER="%{c}"
RIGHT="%{r}"

# Set panel structure - provide a string with a list of modules.
# Add your own modules as you wish.

sp_modules="

sp_spacer
sp_main_menu
sp_separator
sp_bspwm_status
sp_center
sp_window_title
sp_right
sp_separator
sp_conky_info
sp_spacer
"

# Module definitions - each module shoud print one line at a time.
# Dynamic modules should print a line for every new value.
# The panel updates every time a module prints a line.

sp_spacer()
{
    echo " " ;
}

sp_main_menu()
{
    echo "$FC2%{A:morc_menu:}☰%{A}$FC" ;
}

sp_separator()
{
    echo "$SEPARATOR" ;
}

sp_center()
{
    echo "$CENTER" ;
}

sp_right()
{
    echo "$RIGHT" ;
}

sp_bspwm_status()
{
    IFS=':' ;
    bspc subscribe \
    | while read line ; do
        set -- $line ;
        while [ $# -gt 0 ] ; do
            case $1 in
                O*|F*|U*)
                    printf "%s %s %s" "$BC1" "${1#?}" "$BC" ;;
                o*|u*)
                    printf " %s " "${1#?}" ;;
            esac ;
            shift ;
        done ;
        printf "\n" ;
    done ;
}

sp_window_title()
{
    xtitle -s -t -40 ;
}

sp_clock()
{
    while true ; do
        date +%R ;
        sleep 60 ;
    done ;
}

sp_conky_info()
{
echo '
conky.config = {
out_to_x = false,
out_to_console = true,
use_spacer = "left",
default_graph_width = 8,
console_graph_ticks = " ,_,—,‾",
out_to_stderr = false,
cpu_avg_samples = 2,
no_buffers = true,
update_interval = 1
};
conky.text =
[[
CPU:\
${cpugraph}\
${cpu}%\
'$SEPARATOR'\
${wireless_essid wlp2s0}\
${wireless_link_qual_perc wlp2s0}%\
'$SEPARATOR'\
${time %T}
]]
' | conky -q -c - ;
}

########
# MAIN #
########

# INITIALIZE PANEL
sp_values="" ;
for module in $sp_modules ; do # set initial values
    sp_values="$sp_values\n" ;
done ;
i=0 ;
for module in $sp_modules ; do # start modules
    $module \
    | while read line ; do
        printf "%s/%s\n" "$i" "$line"; # add module index to the line
    done & # spawn proccess for dynamic modules
    i=$(($i+1)) ;
done \
| while read line ; do # UPDATE PANEL
        index="${line%%/*}" ; # get index of module that needs update
        new_value="${line#*/}" ; # get new value for that module
        i=0 ;
        sp_values_new="" ;
        while [ -n "$sp_values" ] ; do # read old set of values
            if [ $i -eq $index ] ; then
                value="$new_value" ;   # replace appropriate value
                else
                value="${sp_values%%\\n*}" ; # keep all other values
            fi
            sp_values="${sp_values#*\\n}" ; # remove old value
            printf "%s" "$value" ;
            sp_values_new="$sp_values_new$value\n" ; # write new set of values
            i=$(($i+1)) ;
        done ;
        printf "\n" ;
        sp_values="$sp_values_new" ; # replace old values with new ones
        sleep 0.01 ; # a delay needed for smooth updates
    done \
| lemonbar \
    -g ${SP_WIDTH}x${SP_HEIGHT}${SP_POSITION} \
    -f $SP_FONT_1 \
    -o $SP_OFFSET_1 \
    -f $SP_FONT_2 \
    -o $SP_OFFSET_2 \
    -B $SP_BG_COLOR \
    -F $SP_FG_COLOR \
| while read line; do eval "$line"; done; # execute button commands

wait