wake-eyesome.sh

#!/bin/bash

# NAME: wake-eyesome.sh
# PATH: /lib/systemd/system-sleep/
# DESC: Instantly adjust display brightness when resuming from suspend.
# CALL: systemd calls this script during syspend/resume cycles.
#       Called from command line for testing/debugging.
#       Called by /usr/local/bin/eyesome-cfg.sh when Test button clicked.

# DATE: August 2017. Modified: July 6, 2020.

# UPDT: Jul 06, 2020 Change location of: '/tmp/display-current-brightness'
#           to '/usr/local/bin/.eyesome-percent' and change value from hardware
#           adapter setting to percentage of sunlight. Rename variable from:
#          'CurrentBrightnessFilename' to 'SunlightPercentFilename'.

# PARM: $1 = systemd State = "pre" or "post" for function
#       $2 = systemd Function = "Suspend" or "Hibernate"
#            eyesome-cfg-sh = "eyesome-cfg.sh"
#            acpi-lid-eyesome.sh = "LidOpenClose"
#            eyesome-dbus.sh = "eyesome-dbus.sh"
#            eyesome-sun.sh = "eyesome-sun.sh"
#       $3 = "nosleep" skip sleep time for eyesome-cfg.sh and eyesome-sun.sh
#            Otherwise spam brightness for "LidOpenClose", eyesome-dbus.sh,
#            blank when $2 = "Suspend" or "Hibernate".
#       $4 = Using eyesome-cfg.sh pass "remain" to display seconds remaining
#            but don't kill the sleep command.

source eyesome-src.sh # Common code for eyesome___.sh bash scripts

# log "P1: $1 | P2: $2 | P3: $3 | P4: $4"

case $1/$2 in
  pre/*)
    echo YES > "$EyesomeIsSuspending"
    sync -d "$EyesomeIsSuspending"
    log "Creating $EyesomeIsSuspending"
    ;;
  post/*)
  
    [[ "$4" != "remain" ]] && \
        log "Called from $2."  # When $4=remain no chatter, just secs.

    # Find running tree processes containing "eyesome.sh" AND "sleep"
    ProcessTree=$(pstree -g -p | grep "${EyesomeDaemon##*/}" | grep sleep)

    # Extract sleep process ID in $ProcessTree, we want "16621" below:
    # |-cron(1198,1198)---cron(1257,1198)---sh(1308,1308)--- \
    #                   eyesome.sh(1321,1308)---sleep(16621,1308)

    pID=${ProcessTree##*sleep(}     # cut everything up to & incl "sleep("
    pID=${pID%,*}                   # cut everything after & incl ","

    # Are we just getting time remaining and not waking up?
    if [[ "$4" == "remain" ]] ; then
        if [[ $pID != "" ]]; then
            # Warning returned value can be negative:
            # https://unix.stackexchange.com/questions/314512/how-to-determine-the-amount-of-time-left-in-a-sleep#comment786223_314777
            ps -o etime= -o args= -p "$pID" | perl -MPOSIX -lane '
                %map = qw(d 86400 h 3600 m 60 s 1);
                $F[0] =~ /(\d+-)?(\d+:)?(\d+):(\d+)/;
                $t = -($4+60*($3+60*($2+24*$1)));
                for (@F[2..$#F]) {
                    s/\?//g;
                    ($n, $p) = strtod($_);
                    $n *= $map{substr($_, -$p)} if $p;
                    $t += $n
                }
                print $t'
        else
            printf "0"  # Was not sleeping when checked, 0 time remaining
            EyesomeID=$(pstree -g -p | grep "${EyesomeDaemon##*/}")
            log "No time remaining for eyesome.sh process ID: $EyesomeID"
        fi
        exit 0
    fi

    # eyesome-dbus processes many transactions per second from RAM and can't
    # wait 3 seconds to see if suspend is in process. So do it here.
    # Suspend will wake up eyesome first so there will be no sleep PID to kill.
    if [[ "$2" == "eyesome-dbus.sh" ]] ; then
        log "DBUS: Waiting 3 seconds to see if supending"
        sleep 3
        if [[ -f "$EyesomeIsSuspending" ]] ; then
            log "System supending, Cancel DBUS waking eyesome"
            exit 0 # Don't want to reset brightness!
        fi
    fi

    if [[ "$pID" == "" ]] ; then
        printf "0"  # eyesome.sh daemon isn't running
        EyesomeID=$(pstree -g -p | grep "${EyesomeDaemon##*/}")
        log "Sleeping process ID of eyesome daemon not found! pstree below:"
        log "$EyesomeID"
        exit 0
    fi
    
    # Removing file informs daemon we are resuming from suspend, DBUS or
    # lid was opened/closed. In this case Lightdm takes about 10 seconds
    # reseting some slower TVs/Monitors once or twice. Each reset causes
    # brightness and gamma to reset to 1.00.
    [[ $3 == "" ]] || [[ $3 == "spam" ]] && rm -f "$SunlightPercentFilename"
    
    # Wake up eyesome.sh daemon by killing it's sleep command
    kill "$pID"  # kill sleep command forcing eyesome.sh to wakeup now.
    # log "Sleep pID: '$pID' has been killed."
        
    ;;
esac

exit 0