Calculate suspend time from systemd's journalctl

suspendtime.sh

#!/bin/bash

# NAME: suspendtime
# PATH: $HOME/askubuntu/
# DESC: For: https://askubuntu.com/questions/321855/how-to-get-real-uptime
# DATE: November 6, 2019.

# NOTE: Calculate suspend time from systemd's journalctl

# UPDT:
#       2022-07-07 modified regex
#       2019-11-07 Fine-tune removing 0 Units in DaysMinutesStr
#       2020-05-09 Add "weeks" unit measure to DaysMinutes() function

# Duplicate DaysMinutes from ~/.bashrc for Ask Ubuntu
DaysMinutes () {

    local w d h m s
    (( w = ${1} / 604800 ))
    (( d = ${1}%604800 / 86400 ))
    (( h = (${1}%86400) / 3600 ))
    (( m = (${1}%3600) / 60 ))
    (( s = ${1}%60 ))
    DaysMinutesStr="$w weeks, $d days, $h hours, $m minutes, $s seconds"
    
    # Convert 1's to singular
    [[ ${DaysMinutesStr:0:2} = "1 " ]] && \
        DaysMinutesStr="${DaysMinutesStr/weeks/week}"
    DaysMinutesStr="${DaysMinutesStr/ 1 days/ 1 day}"
    DaysMinutesStr="${DaysMinutesStr/ 1 hours/ 1 hour}"
    DaysMinutesStr="${DaysMinutesStr/ 1 minutes/ 1 minute}"
    DaysMinutesStr="${DaysMinutesStr/ 1 seconds/ 1 second}"

    # Suppress zero strings
    [[ ${DaysMinutesStr:0:1} = "0" ]] &&
        DaysMinutesStr="${DaysMinutesStr/0 weeks, / }"
    DaysMinutesStr="${DaysMinutesStr/ 0 days, / }"
    DaysMinutesStr="${DaysMinutesStr/ 0 hours, / }"
    DaysMinutesStr="${DaysMinutesStr/ 0 minutes, / }"
    DaysMinutesStr="${DaysMinutesStr/, 0 seconds/}"
} # DaysMinutes

# Build array of suspend cycles from Systemd
IFS=$'\n' Arr=( $(journalctl -b-0 | \
                grep -E 'systemd\[1]: (Starting|Finished).*Suspend' | cut -c1-15) )

[[ ${#Arr[@]} -gt 0 ]] && upper=$(( ${#Arr[@]} - 1 ))
[[ $upper -gt 0 ]] && for (( i=0; i<upper; i=i+2 )) ; do
    (( SuspendCount++ ))
    Time=$(( $(date +%s -d "${Arr[i+1]}") - $(date +%s -d "${Arr[i]}") ))
    SuspendTime=$(( SuspendTime + Time ))
    DaysMinutes "$Time"
    printf "%s to %s suspended%s\n" "${Arr[i]}" "${Arr[i+1]}" \
          "$DaysMinutesStr"
done

echo
LinuxTime=$(( $(date +%s -d "Now") - $(date +%s -d "$(uptime -s)") ))
DaysMinutes "$LinuxTime"
printf "Linux uptime %'d seconds (%s)\n" "$LinuxTime" "$DaysMinutesStr"

[[ "$SuspendTime" -ne '' ]] && (
DaysMinutes "$SuspendTime"
printf "%s Suspends %'d seconds (%s)\n" \
        "$SuspendCount" "$SuspendTime" "$DaysMinutesStr"
)
RealTime=$(( LinuxTime - SuspendTime ))
DaysMinutes "$RealTime"
printf "Real uptime %'d seconds (%s)\n" "$RealTime" "$DaysMinutesStr"