X-Git-Url: https://zdv2.bktei.com/gitweb/EVA-2020-02.git/blobdiff_plain/d7138c7fbf2bd7aadb9ccd22f85c227b9a59300d..c8ebb71cde973439d2a2161cc72f170bfed3a25b:/exec/bkgpslog?ds=sidebyside

diff --git a/exec/bkgpslog b/exec/bkgpslog
index 8b3b67e..b69b8be 100755
--- a/exec/bkgpslog
+++ b/exec/bkgpslog
@@ -6,15 +6,15 @@
 
 #==BEGIN Define script parameters==
 ## Logging Behavior parameters
-BUFFER_TTL="60"; # time between file writes
-SCRIPT_TTL="day"; # (day|hour)
+BUFFER_TTL="300"; # time between file writes
+SCRIPT_TTL_TE="day"; # (day|hour)
 #### TZ="UTC"; export TZ; # Default time zone; overridden by '--time-zone=[str]' option
 DIR_TMP_DEFAULT="/dev/shm"; # Default parent of working directory
 
 SCRIPT_TIME_START=$(date +%Y%m%dT%H%M%S.%N);
 PATH="$HOME/.local/bin:$PATH";   # Add "$(systemd-path user-binaries)" path in case apps saved there
 SCRIPT_HOSTNAME=$(hostname);     # Save hostname of system running this script.
-SCRIPT_VERSION="0.3.0";          # Define version of script.
+SCRIPT_VERSION="0.4.4-alpha2";          # Define version of script.
 SCRIPT_NAME="bkgpslog";          # Define basename of script file.
 SCRIPT_URL="https://gitlab.com/baltakatei/ninfacyzga-01"; # Define wesite hosting this script.
 AGE_VERSION="1.0.0-beta2";       # Define version of age (encryption program)
@@ -23,11 +23,12 @@ AGE_URL="https://github.com/FiloSottile/age/releases/tag/v1.0.0-beta2"; # Define
 declare -Ag appRollCall # Associative array for storing app status
 declare -Ag fileRollCall # Associative array for storing file status
 declare -Ag dirRollCall # Associative array for storing dir status
-declare -a recPubKeys # for processArguments function
-declare recipients # for main function
+declare -a argRecPubKeys # for processArguments function
+# declare -a errorHistory # for correcting buffer lag
 
 ## Initialize variables
 OPTION_VERBOSE=""; OPTION_ENCRYPT=""; OPTION_COMPRESS=""; OPTION_TMPDIR="";
+errReset=0; BUFFER_TTL_ADJ_FLOAT="";
 
 #===BEGIN Declare local script functions===
 checkapp() {
@@ -147,35 +148,36 @@ showUsage() {
     echoerr "OPTIONS:"
     echoerr "    -h, --help"
     echoerr "            Display help information."
-    echoerr
     echoerr "    --version"
     echoerr "            Display script version."
-    echoerr
     echoerr "    -v, --verbose"
     echoerr "            Display debugging info."
-    echoerr
     echoerr "    -e, --encrypt"
     echoerr "            Encrypt output."
-    echoerr
-    echoerr "    -r, --recipient [ pubkey string ]"
+    echoerr "    -r, --recipient [ string pubkey ]"
     echoerr "            Specify recipient. May be age or ssh pubkey."
+    echoerr "            May be specified multiple times for multiple pubkeys."
     echoerr "            See https://github.com/FiloSottile/age"
-    echoerr
-    echoerr "    -o, --output [ directory ]"
+    echoerr "    -o, --output [ path dir ]"
     echoerr "            Specify output directory to save logs."
-    echoerr
     echoerr "    -c, --compress"
     echoerr "            Compress output with gzip (before encryption if enabled)."
-    echoerr
     echoerr "    -z, --time-zone"
     echoerr "            Specify time zone. (ex: \"America/New_York\")"
-    echoerr
-    echoerr "    -t, --temp-dir"
+    echoerr "    -t, --temp-dir [path dir]"
     echoerr "            Specify parent directory for temporary working directory."
     echoerr "            Default: \"/dev/shm\""
+    echoerr "    -R, --recipient-dir [path dir]"
+    echoerr "            Specify directory containing files whose first lines are"
+    echoerr "            to be interpreted as pubkey strings (see \\'-r\\' option)."
+    echoerr "    -b, --buffer-ttl [integer]"
+    echoerr "            Specify custom buffer period in seconds (default: 300 seconds)"
+    echoerr "    -B, --script-ttl [integer]"
+    echoerr "            Specify custom script time-to-live in seconds (default: \"day\")"
     echoerr
     echoerr "EXAMPLE: (bash script lines)"
-    echoerr "/bin/bash bkgpslog -e -c \\"
+    echoerr "/bin/bash bkgpslog -v -e -c \\"
+    echoerr "-z \"UTC\" -t \"/dev/shm\" \\"
     echoerr "-r age1mrmfnwhtlprn4jquex0ukmwcm7y2nxlphuzgsgv8ew2k9mewy3rs8u7su5 \\"
     echoerr "-r age1ala848kqrvxc88rzaauc6vc5v0fqrvef9dxyk79m0vjea3hagclswu0lgq \\"
     echoerr "-o ~/Sync/Location"
@@ -214,12 +216,14 @@ processArguments() {
 	    --version) showVersion; exit 1;; # Show version
 	    -v | --verbose) OPTION_VERBOSE="true"; vbm "DEBUG:Verbose mode enabled.";; # Enable verbose mode.
 	    -o | --output) if [ -d "$2" ]; then DIR_OUT="$2"; vbm "DEBUG:DIR_OUT:$DIR_OUT"; shift; fi ;; # Define output directory.
-	    -e | --encrypt) OPTION_ENCRYPT="true"; vbm "DEBUG:Encrypted output mode enabled.";;
-	    -r | --recipient) # Add 'age' recipient via public key string
-		recPubKeys+=("$2"); vbm "STATUS:pubkey added:""$2"; shift;;
-	    -c | --compress) OPTION_COMPRESS="true"; vbm "DEBUG:Compressed output mode enabled.";;
-	    -z | --time-zone) try setTimeZoneEV "$2"; shift;;
-	    -t | --temp-dir) OPTION_TMPDIR="true" && TMP_DIR_PRIORITY="$2"; shift;;
+	    -e | --encrypt) OPTION_ENCRYPT="true"; vbm "DEBUG:Encrypted output mode enabled.";; # Enable encryption
+	    -r | --recipient) OPTION_RECIPIENTS="true"; argRecPubKeys+=("$2"); vbm "STATUS:pubkey added:""$2"; shift;; # Add recipients
+	    -c | --compress) OPTION_COMPRESS="true"; vbm "DEBUG:Compressed output mode enabled.";; # Enable compression
+	    -z | --time-zone) try setTimeZoneEV "$2"; shift;; # Set timestamp timezone
+	    -t | --temp-dir) OPTION_TMPDIR="true" && argTempDirPriority="$2"; shift;; # Set time zone
+	    -R | --recipient-dir) OPTION_RECIPIENTS="true"; OPTION_RECDIR="true" && argRecDir="$2"; shift;; # Add recipient watch dir
+	    -b | --buffer-ttl) OPTION_CUSTOM_BUFFERTTL="true" && argCustomBufferTTL="$2"; shift;; # Set custom buffer period (default: 300 seconds)
+	    -B | --script-ttl) OPTION_CUSTOM_SCRIPTTTL_TE="true" && argCustomScriptTTL="$2"; shift;; # Set custom script TTL (default: "day")
 	    *) echoerr "ERROR: Unrecognized argument: $1"; echoerr "STATUS:All arguments:$*"; exit 1;; # Handle unrecognized options.
 	esac
 	shift
@@ -334,20 +338,64 @@ timeUntilNextHour(){
 } # Report seconds until next hour
 dateTimeShort(){
     # Desc: Timestamp without separators (YYYYmmddTHHMMSS+zzzz)
-    # Usage: dateTimeShort
+    # Usage: dateTimeShort ([str date])
+    # Version 1.1.0
+    # Input: arg1: 'date'-parsable timestamp string (optional)
     # Output: stdout: timestamp (ISO-8601, no separators)
+    # Depends: yell
     local TIME_CURRENT TIME_CURRENT_SHORT
+
+    argTime="$1";
+    # Get Current Time
     TIME_CURRENT="$(date --iso-8601=seconds)" ; # Produce `date`-parsable current timestamp with resolution of 1 second.
-    TIME_CURRENT_SHORT="$(date -d "$TIME_CURRENT" +%Y%m%dT%H%M%S%z)"; # Produce separator-less current timestamp with resolution 1 second.
+    # Decide to parse current or supplied date
+    ## Check if time argument empty
+    if [[ -z "$argTime" ]]; then
+	## T: Time argument empty, use current time
+	TIME_INPUT="$TIME_CURRENT";
+    else
+	## F: Time argument exists, validate time
+	if date --date="$argTime" 1>/dev/null 2>&1; then
+	    ### T: Time argument is valid; use it
+	    TIME_INPUT="$argTime";
+	else
+	    ### F: Time argument not valid; exit
+	    yell "ERROR:Invalid time argument supplied. Exiting."; exit 1;
+	fi
+    fi
+    # Construct and deliver separator-les date string
+    TIME_CURRENT_SHORT="$(date -d "$TIME_INPUT" +%Y%m%dT%H%M%S%z)";
     echo "$TIME_CURRENT_SHORT";
 } # Get YYYYmmddTHHMMSS±zzzz
 dateShort(){
     # Desc: Date without separators (YYYYmmdd)
-    # Usage: dateShort
+    # Usage: dateShort ([str date])
+    # Version: 1.1.0
+    # Input: arg1: 'date'-parsable timestamp string (optional)
     # Output: stdout: date (ISO-8601, no separators)
+    # Depends: yell
     local TIME_CURRENT DATE_CURRENT_SHORT
+
+    argTime="$1";
+    # Get Current Time
     TIME_CURRENT="$(date --iso-8601=seconds)" ; # Produce `date`-parsable current timestamp with resolution of 1 second.
-    DATE_CURRENT_SHORT="$(date -d "$TIME_CURRENT" +%Y%m%d)"; # Produce separator-less current date with resolution 1 day.
+    # Decide to parse current or supplied date
+    ## Check if time argument empty
+    if [[ -z "$argTime" ]]; then
+	## T: Time argument empty, use current time
+	TIME_INPUT="$TIME_CURRENT";
+    else
+	## F: Time argument exists, validate time
+	if date --date="$argTime" 1>/dev/null 2>&1; then
+	    ### T: Time argument is valid; use it
+	    TIME_INPUT="$argTime";
+	else
+	    ### F: Time argument not valid; exit
+	    yell "ERROR:Invalid time argument supplied. Exiting."; exit 1;
+	fi
+    fi
+    # Construct and deliver separator-les date string    
+    DATE_CURRENT_SHORT="$(date -d "$TIME_INPUT" +%Y%m%d)"; # Produce separator-less current date with resolution 1 day.
     echo "$DATE_CURRENT_SHORT";
 } # Get YYYYmmdd
 timeDuration(){
@@ -597,34 +645,34 @@ displayMissing() {
 
     #==END Display errors==
 } # Display missing apps, files, dirs
-setScriptTTL() {
-    #Desc: Sets script TTL
-    #Usage: setScriptTTL arg1
-    #Input: arg1: "day" or "hour"
-    #Output: scriptTTL
-    #Depends: timeUntilNextHour or timeUntilNextDay
-    local ARG1
-    ARG1="$1"
-    if [[ "$ARG1" = "day" ]]; then
+magicSetScriptTTL() {
+    #Desc: Sets script_TTL seconds from provided time_element string argument
+    #Usage: magicSetScriptTTL [str time_element]
+    #Input: arg1: string (Ex: SCRIPT_TTL_TE; "day" or "hour")
+    #Output: var: SCRIPT_TTL (integer seconds)
+    #Depends: timeUntilNextHour, timeUntilNextDay
+    local argTimeElement
+    argTimeElement="$1"
+    if [[ "$argTimeElement" = "day" ]]; then
 	    # Set script lifespan to end at start of next day
-	if ! scriptTTL="$(timeUntilNextDay)"; then
-	    if [[ "$scriptTTL" -eq 0 ]]; then
-	    ((scriptTTL++)); # Add 1 because 0 would cause 'timeout' to never timeout.
+	if ! SCRIPT_TTL="$(timeUntilNextDay)"; then
+	    if [[ "$SCRIPT_TTL" -eq 0 ]]; then
+	    ((SCRIPT_TTL++)); # Add 1 because 0 would cause 'timeout' to never timeout.
 	    else
 	    yell "ERROR: timeUntilNextDay exit code $?"; exit 1;
 	    fi;
 	fi;
-    elif [[ "$ARG1" = "hour" ]]; then
+    elif [[ "$argTimeElement" = "hour" ]]; then
 	# Set script lifespan to end at start of next hour
-	if ! scriptTTL="$(timeUntilNextHour)"; then
-	    if [[ "$scriptTTL" -eq 0 ]]; then
-		((scriptTTL++)); # Add 1 because 0 would cause 'timeout' to never timeout.
+	if ! SCRIPT_TTL="$(timeUntilNextHour)"; then
+	    if [[ "$SCRIPT_TTL" -eq 0 ]]; then
+		((SCRIPT_TTL++)); # Add 1 because 0 would cause 'timeout' to never timeout.
 	    else
 		yell "ERROR: timeUntilNextHour exit code $?"; exit 1;
 	    fi;
 	fi;
     else
-	yell "ERROR:Invalid argument for setScriptTTL function."; exit 1;
+	yell "ERROR:Invalid argument for setScriptTTL function:$argTimeElement"; exit 1;
     fi
 } # Seconds until next (day|hour).
 checkMakeTar() {
@@ -669,8 +717,8 @@ checkMakeTar() {
 } # checks if arg1 is tar; creates one otherwise
 appendArgTar(){
     # Desc: Writes first argument to temporary file with arguments as options, then appends file to tar
-    # Usage: writeArg "$(echo "Data to be written.")" [name of file to be inserted] [tar path] [temp dir] ([cmd1] [cmd2] [cmd3] [cmd4]...)
-    # Version: 1.0.0
+    # Usage: appendArgTar "$(echo "Data to be written.")" [name of file to be inserted] [tar path] [temp dir] ([cmd1] [cmd2] [cmd3] [cmd4]...)
+    # Version: 1.0.3
     # Input: arg1: data to be written
     #        arg2: file name of file to be inserted into tar
     #        arg3: tar archive path (must exist first)
@@ -682,6 +730,7 @@ appendArgTar(){
     #          appendArgTar "$(cat /tmp/largefile2.gpg)" "largefile2" $HOME/archive.tar /tmp "gpg --decrypt" &
     #          appendArgTar "$(cat /tmp/largefile3.gpg)" "largefile3" $HOME/archive.tar /tmp "gpg --decrypt" &
     # Depends: bash 5
+    # Ref/Attrib: Using 'eval' to construct command strings https://askubuntu.com/a/476533
 
     # Save function name
     local FN="${FUNCNAME[0]}";
@@ -702,7 +751,11 @@ appendArgTar(){
     if ! [ -z "$7" ]; then CMD3="$7"; else CMD3="tee /dev/null "; fi # command string 3
     if ! [ -z "$8" ]; then CMD4="$8"; else CMD4="tee /dev/null "; fi # command string 4
 
+    # Input command
+    CMD0="echo \"\$1\""
+
     # # Debug
+    # yell "DEBUG:STATUS:$FN:CMD0:$CMD0"
     # yell "DEBUG:STATUS:$FN:CMD1:$CMD1"
     # yell "DEBUG:STATUS:$FN:CMD2:$CMD2"
     # yell "DEBUG:STATUS:$FN:CMD3:$CMD3"
@@ -712,12 +765,255 @@ appendArgTar(){
     # yell "DEBUG:STATUS:$FN:TMP_DIR:$TMP_DIR"
     
     # Write to temporary working dir
-    echo "$1" | $CMD1 | $CMD2 | $CMD3 | $CMD4 > "$TMP_DIR"/"$FILENAME";
+    eval "$CMD0"" | ""$CMD1"" | ""$CMD2"" | ""$CMD3"" | ""$CMD4" > "$TMP_DIR"/"$FILENAME";
 
     # Append to tar
     try tar --append --directory="$TMP_DIR" --file="$TAR_PATH" "$FILENAME";
     #yell "DEBUG:STATUS:$FN:Finished appendArgTar()."
 } # Append Bash var to file appended to Tar archive
+appendFileTar(){
+    # Desc: Processes first file and then appends to tar
+    # Usage: appendFileTar [file path] [name of file to be inserted] [tar path] [temp dir] ([cmd1] [cmd2] [cmd3] [cmd4]...)
+    # Version: 1.0.2
+    # Input: arg1: path of file to be (processed and) written
+    #        arg2: name to use for file inserted into tar
+    #        arg3: tar archive path (must exist first)
+    #        arg4: temporary working dir
+    #        arg5+: command strings (ex: "gpsbabel -i nmea -f - -o kml -F - ")
+    # Output: file written to disk
+    # Example: decrypt multiple large files in parallel
+    #          appendFileTar /tmp/largefile1.gpg "largefile1" $HOME/archive.tar /tmp "gpg --decrypt" &
+    #          appendFileTar /tmp/largefile2.gpg "largefile2" $HOME/archive.tar /tmp "gpg --decrypt" &
+    #          appendFileTar /tmp/largefile3.gpg "largefile3" $HOME/archive.tar /tmp "gpg --decrypt" &
+    # Depends: bash 5
+
+    # Save function name
+    local FN="${FUNCNAME[0]}";
+    #yell "DEBUG:STATUS:$FN:Finished appendFileTar()."
+    
+    # Set file name
+    if ! [ -z "$2" ]; then FILENAME="$2"; else yell "ERROR:$FN:Not enough arguments."; exit 1; fi
+    # Check tar path is a file
+    if [ -f "$3" ]; then TAR_PATH="$3"; else yell "ERROR:$FN:Tar archive arg not a file."; exit 1; fi
+    # Check temp dir arg
+    if ! [ -z "$4" ]; then TMP_DIR="$4"; else yell "ERROR:$FN:No temporary working dir set."; exit 1; fi
+    # Set command strings
+    if ! [ -z "$5" ]; then CMD1="$5"; else CMD1="tee /dev/null "; fi # command string 1
+    if ! [ -z "$6" ]; then CMD2="$6"; else CMD2="tee /dev/null "; fi # command string 2
+    if ! [ -z "$7" ]; then CMD3="$7"; else CMD3="tee /dev/null "; fi # command string 3
+    if ! [ -z "$8" ]; then CMD4="$8"; else CMD4="tee /dev/null "; fi # command string 4
+
+    # Input command string
+    CMD0="cat \"\$1\""
+    
+    # # Debug
+    # yell "DEBUG:STATUS:$FN:CMD0:$CMD0"
+    # yell "DEBUG:STATUS:$FN:CMD1:$CMD1"
+    # yell "DEBUG:STATUS:$FN:CMD2:$CMD2"
+    # yell "DEBUG:STATUS:$FN:CMD3:$CMD3"
+    # yell "DEBUG:STATUS:$FN:CMD4:$CMD4"
+    # yell "DEBUG:STATUS:$FN:FILENAME:$FILENAME"
+    # yell "DEBUG:STATUS:$FN:TAR_PATH:$TAR_PATH"
+    # yell "DEBUG:STATUS:$FN:TMP_DIR:$TMP_DIR"
+    
+    # Write to temporary working dir
+    eval "$CMD0 | $CMD1 | $CMD2 | $CMD3 | $CMD4" > "$TMP_DIR"/"$FILENAME";
+
+    # Append to tar
+    try tar --append --directory="$TMP_DIR" --file="$TAR_PATH" "$FILENAME";
+    #yell "DEBUG:STATUS:$FN:Finished appendFileTar()."
+} # Append file to Tar archive
+checkAgePubkey() {
+    # Desc: Checks if string is an age-compatible pubkey
+    # Usage: checkAgePubkey [str pubkey]
+    # Version: 0.1.2
+    # Input: arg1: string
+    # Output: return code 0: string is age-compatible pubkey
+    #         return code 1: string is NOT an age-compatible pubkey
+    #         age stderr (ex: there is stderr if invalid string provided)
+    # Depends: age (v0.1.0-beta2; https://github.com/FiloSottile/age/releases/tag/v1.0.0-beta2 )
+    
+    argPubkey="$1";
+    
+    if echo "test" | age -a -r "$argPubkey" 1>/dev/null; then
+	return 0;
+    else
+	return 1;
+    fi;
+} # Check age pubkey
+validateInput() {
+    # Desc: Validates Input
+    # Usage: validateInput [str input] [str input type]
+    # Version: 0.3.0
+    # Input: arg1: string to validate
+    #        arg2: string specifying input type (ex:"ssh_pubkey")
+    # Output: return code 0: if input string matched specified string type
+    # Depends: bash 5, yell
+
+    # Save function name
+    local FN="${FUNCNAME[0]}";
+
+    # Process arguments
+    argInput="$1";
+    argType="$2";
+    if [[ $# -gt 2 ]]; then yell "ERROR:$0:$FN:Too many arguments."; exit 1; fi;
+
+    # Check for blank
+    if [[ -z "$argInput" ]]; then return 1; fi
+    
+    # Define input types
+    ## ssh_pubkey
+    ### Check for alnum/dash base64 (ex: "ssh-rsa AAAAB3NzaC1yc2EAAA")
+    if [[ "$argType" = "ssh_pubkey" ]]; then
+	if [[ "$argInput" =~ ^[[:alnum:]-]*[\ ]*[[:alnum:]+/=]*$ ]]; then
+	    return 0; fi; fi;
+
+    ## age_pubkey
+    ### Check for age1[:bech32:]
+    if [[ "$argType" = "age_pubkey" ]]; then
+	if [[ "$argInput" =~ ^age1[qpzry9x8gf2tvdw0s3jn54khce6mua7l]*$ ]]; then
+	    return 0; fi; fi
+
+    ## integer
+    if [[ "$argType" = "integer" ]]; then
+	if [[ "$argInput" =~ ^[[:digit:]]*$ ]]; then
+	    return 0; fi; fi;
+
+    ## time element (year, month, week, day, hour, minute, second)
+    if [[ "$argType" = "time_element" ]]; then
+	if [[ "$argInput" = "year" ]] || \
+	       [[ "$argInput" = "month" ]] || \
+	       [[ "$argInput" = "week" ]] || \
+	       [[ "$argInput" = "day" ]] || \
+	       [[ "$argInput" = "hour" ]] || \
+	       [[ "$argInput" = "minute" ]] || \
+	       [[ "$argInput" = "second" ]]; then
+	    return 0; fi; fi;
+    
+    # Return error if no condition matched.
+    return 1;
+} # Validates strings
+timeEpochNS() {
+    # Desc: Get epoch nanoseconds
+    # Usage: timeEpochNS
+    # Version 0.2.2
+    # Input: arg1: 'date'-parsable timestamp string (optional)
+    # Output: Nanoseconds since 1970-01-01
+    # Depends: date 8, yell()
+    # Ref/Attrib: Force base 10 Bash arith with '10#'. https://stackoverflow.com/a/24777667
+    local TIME_CURRENT TIME_INPUT TIME_EPOCH_FLOAT TIME_EPOCH_NSFRAC
+    local TIME_EPOCH_NS
+
+    argTime="$1";
+
+    # Get Current Time
+    TIME_CURRENT="$(date --iso-8601=ns)"; # Produce `date`-parsable current timestamp with resolution of 1 nanosecond.
+
+    # Decide to parse current or supplied time
+    ## Check if time argument empty
+    if [[ -z "$argTime" ]]; then
+	## T: Time argument empty, use current time
+	TIME_INPUT="$TIME_CURRENT";
+    else
+	## F: Time argument exists, validate time
+	if date --date="$argTime" 1>/dev/null 2>&1; then
+	    ### T: Time argument is valid; use it
+	    TIME_INPUT="$argTime";
+	else
+	    ### F: Time argument not valid; exit
+	    yell "ERROR:Invalid time argument supplied. Exiting."; exit 1;
+	fi;
+    fi;
+    # Construct and deliver nanoseconds since 1970-01-01    
+    TIME_EPOCH_FLOAT="$(date --date="$TIME_INPUT" +%s.%N)"; # Save ssss.NNNNNNNNN
+    TIME_EPOCH_INT="$(echo "$TIME_EPOCH_FLOAT" | cut -d. -f1)"; # Get ssss
+    TIME_EPOCH_NSFRAC="$(echo "$TIME_EPOCH_FLOAT" | cut -d. -f2)"; # Get NNNNNNNNN
+    TIME_EPOCH_NS="$(( (10#"$TIME_EPOCH_INT" * 10**9) + (10#"$TIME_EPOCH_NSFRAC") ))";
+    echo "$TIME_EPOCH_NS";
+} # Nanoseconds since 1970-01-01
+magicBufferSleepPID() {
+    # Desc: Compensates for lag so buffer rounds start every BUFFER_TTL seconds
+    # Input: vars: BUFFER_TTL, errResetx10e3, K_P, T_I, T_D
+    # # Input: array: errorHistory
+    # Output: vars: BUFFER_TTL_ADJ_FLOAT
+    # Re/Attrib: https://en.wikipedia.org/wiki/PID_controller#Standard_versus_parallel_(ideal)_form
+    local BUFFER_TTL_NS
+    local timeBufferStartNS timeBufferStartNSExp errNS errNSx10e3
+    local errResetx10e3 errRatex10e3 ADJ BUFFER_TTL_ADJ_NS BUFFER_TTL_ADJ_INT
+    local BUFFER_TTL_ADJ_FLOATFRAC
+    # local errorHistorySize
+    
+    # ## Define errorHistorySize
+    # errorHistorySize=100;
+    ## Define BUFFER_TTL in nanoseconds
+    BUFFER_TTL_NS=$((BUFFER_TTL * 10**9)) && vbm "BUFFER_TTL_NS:$BUFFER_TTL_NS";
+
+    ### PID Control factors
+    K_P=1; # Gain for compensating buffer round lag
+    T_I="$(((4)*BUFFER_TTL_NS/(1)))"; # Consider this number of past nanoseconds to eliminate error
+    T_D="$(((1)*BUFFER_TTL_NS/(1)))"; # Predict value this number of nanoseconds into the future
+    
+    # Calculate Error, errNS, in nanoseconds
+    ## Get current time
+    timeBufferStartNS="$(timeEpochNS)" && vbm "timeBufferStartNS   :$timeBufferStartNS";
+    ## Calculate expected time (from start time, current buffer round number, nominal BUFFER_TTL)
+    timeBufferStartNSExp="$(( (timeBufferFirstNS) + (BUFFER_TTL_NS * bufferRound) ))" && vbm "timeBufferStartNSExp:$timeBufferStartNSExp";
+    ## Calculate error (diff between timeBufferStartNSExp and timeBufferStartNS; usually negative)
+    errNS="$(( timeBufferStartNSExp - timeBufferStartNS ))" && vbm "errNS:$errNS";
+#    errNSx10e3="$((errNS*10**3))" && vbm "errNSx10e3:$errNSx10e3";
+    # ## Append error to errorHistory
+    # errorHistory+=("errNS");
+    # ### Trim errorHistory array if over errorHistorySize
+    # while [[ "${#errorHistory[@]}" -gt "errorHistorySize" ]]; then do
+    # 	unset "errorHistory[0]"; # remove oldest entry, creating sparse array
+    # 	errorHistory=("${errorHistory[@]}"); # reindex sparse array
+    # 	vbm "STATUS:Trimmed errorHistory array. Entry count:${#errorHistory[@]}";
+    # done;
+
+    # Calculate errReset in nanoseconds^2
+    ## errReset = int(errHistory(t),wrt(delta_BUFFER_TTL))
+    ## Integrate errorHistory with respect to time
+    # for value in "${errorHistory[@]}"; do
+    # 	errReset=$(( errReset + ( value*BUFFER_TTL_NS ) ));
+    # done;
+    vbm "errReset(orig):$errReset"
+    errReset="$(( (errReset + (errNS*BUFFER_TTL_NS)) ))" && vbm "errReset(post):$errReset";
+#    errResetx10e3="$(( ( errResetx10e3 + ( errNSx10e3 * BUFFER_TTL_NS ) )*10**3 ))" && vbm "errResetx10e3:$errResetx10e3";
+
+    # Calculate errRate in nanoseconds per nanosecond
+    errRate="$(( errNS / BUFFER_TTL_NS ))" && vbm "errRate:$errRate";
+#    errRatex10e3="$(( ( errNSx10e3 ) / BUFFER_TTL_NS ))" && vbm "errRatex10e3:$errRatex10e3";
+
+    # Debug
+    vbm "errNS       :$errNS";
+    vbm "errResetTerm:$((errReset/T_I))";
+    vbm "errRateTerm :$((errRate*T_D))";
+    
+    # Calculate PID control signal
+    ## ADJ = K_P * (errNS + errReset/T_I + errRate*T_D)
+    ADJ="$(( K_P*(errNS + errReset/T_I + errRate*T_D) ))" && vbm "ADJ:$ADJ";
+#    ADJ="$((K_P*(errNSx10e3 + (errResetx10e3/T_I) + (errRatex10e3*T_D) )/(10**3)))" && vbm "ADJ:$ADJ";
+
+    # Calculate BUFFER_TTL_ADJ_FLOAT from ADJ (ns)
+    ## Calculate BUFFER_TTL_ADJ in nanoseconds (BUFFER_TTL_ADJ_NS = BUFFER_TTL_NS + ADJ)
+    BUFFER_TTL_ADJ_NS="$((BUFFER_TTL_NS + ADJ))" && vbm "BUFFER_TTL_ADJ_NS:$BUFFER_TTL_ADJ_NS";
+    ## Calculate integer seconds
+    BUFFER_TTL_ADJ_INT="$((BUFFER_TTL_ADJ_NS/(10**9)))" && vbm "BUFFER_TTL_ADJ_INT:$BUFFER_TTL_ADJ_INT";
+    ### Catch negative integer seconds, set minimum of BUFFER_TTL/10 seconds
+    if [[ "$BUFFER_TTL_ADJ_INT" -le "$((BUFFER_TTL/10))" ]]; then
+	BUFFER_TTL_ADJ_INT="$((BUFFER_TTL/10))";
+	yell "WARNING:Buffer lag adjustment yielded negative seconds.";
+    fi;
+    ## Calculate nanosecond remainder
+    ### Remove integer
+    BUFFER_TTL_ADJ_FLOATFRAC="$((BUFFER_TTL_ADJ_NS - (BUFFER_TTL_ADJ_INT*(10**9)) ))" && vbm "BUFFER_TTL_ADJ_FLOATFRAC:$BUFFER_TTL_ADJ_FLOATFRAC";
+    ### Calc absolute value of fraction (by removing '-' if present; see https://stackoverflow.com/a/47240327
+    BUFFER_TTL_ADJ_FLOATFRAC="${BUFFER_TTL_ADJ_FLOATFRAC#-}" && vbm "BUFFER_TTL_ADJ_FLOATFRAC:$BUFFER_TTL_ADJ_FLOATFRAC";
+    ## Form float BUFFER_TTL_ADJ_FLOAT
+    BUFFER_TTL_ADJ_FLOAT="$BUFFER_TTL_ADJ_INT"."$BUFFER_TTL_ADJ_FLOATFRAC" && vbm "BUFFER_TTL_ADJ_FLOAT:$BUFFER_TTL_ADJ_FLOAT";
+    vbm "STATUS:Calculated adjusted BUFFER_TTL (seconds):$BUFFER_TTL_ADJ_FLOAT";
+    sleep 1 # Debug
+} # Calc BUFFER_TTL_ADJ_FLOAT so buffer starts every BUFFER_TTL seconds
 magicWriteVersion() {
     # Desc: Appends time-stamped VERSION to PATHOUT_TAR
     # Usage: magicWriteVersion
@@ -752,108 +1048,267 @@ magicWriteVersion() {
     appendArgTar "$CONTENT_VERSION" "$FILEOUT_VERSION" "$PATHOUT_TAR" "$DIR_TMP";
     
 } # bkgpslog: write version data to PATHOUT_TAR via appendArgTar()
-magicWriteBuffer() {
+magicGatherWriteBuffer() {
     # Desc: bkgpslog-specific meta function for writing data to DIR_TMP then appending each file to PATHOUT_TAR
-    # Inputs: PATHOUT_TAR FILEOUT_{NMEA,GPX,KML} CMD_CONV_{NMEA,GPX,KML} CMD_{COMPRESS,ENCRYPT} DIR_TMP
-    # Depends: yell, try, vbm, appendArgTar, tar
-    local FN="${FUNCNAME[0]}";
-    wait; # Wait to avoid collision with older magicWriteBuffer() instances (see https://www.tldp.org/LDP/abs/html/x9644.html )
-    vbm "DEBUG:STATUS:$FN:Started magicWriteBuffer().";
+    # Inputs: vars: PATHOUT_TAR FILEOUT_{NMEA,GPX,KML} CMD_CONV_{NMEA,GPX,KML} CMD_{COMPRESS,ENCRYPT} DIR_TMP,
+    # Inputs: vars: BUFFER_TTL bufferTTL_STR SCRIPT_HOSTNAME CMD_COMPRESS_SUFFIX CMD_ENCRYPT_SUFFIX
+    # Output: file: (PATHOUT_TAR)
+    # Depends: yell(), try(), vbm(), appendArgTar(), tar 1, sleep 8, checkMakeTar()
+    # Depends: magicWriteVersion(), appendFileTar()
+    local FN
 
+    # Debug:Get function name
+    FN="${FUNCNAME[0]}";
+    
+    # Create buffer file with unique name
+    PATHOUT_BUFFER="$DIR_TMP/buffer$SECONDS";
+    # Fill buffer
+    timeout "$BUFFER_TTL"s gpspipe -r -o "$PATHOUT_BUFFER" ;
+    timeBufferStart="$(dateTimeShort  "$(date --date="$BUFFER_TTL seconds ago")")"; # Note start time
+    vbm "DEBUG:STATUS:$FN:Started magicWriteBuffer().";
+    # Determine file paths (time is start of buffer period)
+    FILEOUT_BASENAME="$timeBufferStart""--""$bufferTTL_STR""..""$SCRIPT_HOSTNAME""_location" && vbm "STATUS:Set FILEOUT_BASENAME to:$FILEOUT_BASENAME";
+    ## Files saved to DIR_TMP
+    FILEOUT_NMEA="$FILEOUT_BASENAME".nmea"$CMD_COMPRESS_SUFFIX""$CMD_ENCRYPT_SUFFIX" && vbm "STATUS:Set FILEOUT_NMEA to:$FILEOUT_NMEA";
+    FILEOUT_GPX="$FILEOUT_BASENAME".gpx"$CMD_COMPRESS_SUFFIX""$CMD_ENCRYPT_SUFFIX" && vbm "STATUS:Set FILEOUT_GPX to:$FILEOUT_GPX";
+    FILEOUT_KML="$FILEOUT_BASENAME".kml"$CMD_COMPRESS_SUFFIX""$CMD_ENCRYPT_SUFFIX" && vbm "STATUS:Set FILEOUT_KML to:$FILEOUT_KML";
+    PATHOUT_NMEA="$DIR_TMP"/"$FILEOUT_NMEA" && vbm "STATUS:Set PATHOUT_NMEA to:$PATHOUT_NMEA";
+    PATHOUT_GPX="$DIR_TMP"/"$FILEOUT_GPX" && vbm "STATUS:Set PATHOUT_GPX to:$PATHOUT_GPX";
+    PATHOUT_KML="$DIR_TMP"/"$FILEOUT_KML" && vbm "STATUS:Set PATHOUT_KML to:$PATHOUT_KML";
+    ## Files saved to disk (DIR_OUT)
+    ### one file per day (Ex: "20200731..hostname_location.[.gpx.gz].tar")
+    PATHOUT_TAR="$DIR_OUT"/"$(dateShort "$(date --date="$BUFFER_TTL seconds ago")")".."$SCRIPT_HOSTNAME""_location""$CMD_COMPRESS_SUFFIX""$CMD_ENCRYPT_SUFFIX".tar && \
+	vbm "STATUS:Set PATHOUT_TAR to:$PATHOUT_TAR";
+    # DEBUG: check vars
+    vbm "STATUS:DIR_TMP     :$DIR_TMP";
+    vbm "STATUS:PATHOUT_TAR :$PATHOUT_TAR";
+    vbm "STATUS:PATHOUT_NMEA:$PATHOUT_NMEA";
+    vbm "STATUS:PATHOUT_GPX:$PATHOUT_GPX";
+    vbm "STATUS:PATHOUT_KML:$PATHOUT_KML";
+    
+    
     # Validate PATHOUT_TAR as tar.
     checkMakeTar "$PATHOUT_TAR";
     ## Add VERSION file if checkMakeTar had to create a tar (exited 1) or replace one (exited 2)
     if [[ $? -eq 1 ]] || [[ $? -eq 2 ]]; then magicWriteVersion; fi
 
     # Write bufferBash to PATHOUT_TAR
-    appendArgTar "$bufferBash" "$FILEOUT_NMEA" "$PATHOUT_TAR" "$DIR_TMP" "$CMD_CONV_NMEA" "$CMD_COMPRESS" "$CMD_ENCRYPT"; # Write NMEA data
-    appendArgTar "$bufferBash" "$FILEOUT_GPX" "$PATHOUT_TAR" "$DIR_TMP" "$CMD_CONV_GPX" "$CMD_COMPRESS" "$CMD_ENCRYPT"; # Write GPX file
-    appendArgTar "$bufferBash" "$FILEOUT_KML" "$PATHOUT_TAR" "$DIR_TMP" "$CMD_CONV_KML" "$CMD_COMPRESS" "$CMD_ENCRYPT"; # Write KML file
+    wait; # Wait to avoid collision with older magicWriteBuffer() instances (see https://www.tldp.org/LDP/abs/html/x9644.html )
+    appendFileTar "$PATHOUT_BUFFER" "$FILEOUT_NMEA" "$PATHOUT_TAR" "$DIR_TMP" "$CMD_CONV_NMEA" "$CMD_COMPRESS" "$CMD_ENCRYPT"; # Write NMEA data
+    appendFileTar "$PATHOUT_BUFFER" "$FILEOUT_GPX" "$PATHOUT_TAR" "$DIR_TMP" "$CMD_CONV_GPX" "$CMD_COMPRESS" "$CMD_ENCRYPT"; # Write GPX file
+    appendFileTar "$PATHOUT_BUFFER" "$FILEOUT_KML" "$PATHOUT_TAR" "$DIR_TMP" "$CMD_CONV_KML" "$CMD_COMPRESS" "$CMD_ENCRYPT"; # Write KML file
+
     # Remove secured chunks from DIR_TMP
-    try rm "$PATHOUT_NMEA" "$PATHOUT_GPX" "$PATHOUT_KML";
-    yell "DEBUG:STATUS:$FN:Finished magicWriteBuffer().";
-} # bkgpslog write function
+    rm "$PATHOUT_BUFFER" "$PATHOUT_NMEA" "$PATHOUT_GPX" "$PATHOUT_KML";
+    vbm "DEBUG:STATUS:$FN:Finished magicWriteBuffer().";
+} # write buffer to disk
+magicParseRecipientDir() {
+    # Desc: Updates recPubKeysValid with pubkeys in dir specified by '-R' option ("recipient directory")
+    # Inputs:  vars: OPTION_RECDIR, argRecDir, OPTION_ENCRYPT
+    #          arry: recPubKeysValid
+    # Outputs: arry: recPubKeysValid
+    # Depends: processArguments,
+    local recFileLine updateRecipients recipientDir
+    declare -a candRecPubKeysValid
 
-main() {
-    processArguments "$@" # Process arguments.
-    
-    # Determine working directory
-    ## Set DIR_TMP_PARENT to user-specified value if specified
-    if [[ "$OPTION_TMPDIR" = "true" ]]; then
-	    if [[ -d "$TMP_DIR_PRIORITY" ]]; then
-	    DIR_TMP_PARENT="$OPTION_TMPDIR"; 
+    # Check that '-e' and '-R' set
+    if [[ "$OPTION_ENCRYPT" = "true" ]] && [[ "$OPTION_RECDIR" = "true" ]]; then
+	### Check that argRecDir is a directory.
+	if [[ -d "$argRecDir" ]]; then
+	    recipientDir="$argRecDir" && vbm "STATUS:Recipient watch directory detected:\"$recipientDir\"";
+	    #### Initialize variable indicating outcome of pubkey review
+	    unset updateRecipients
+	    #### Add existing recipients
+	    candRecPubKeysValid=("${recPubKeysValidStatic[@]}");
+	    #### Parse files in recipientDir
+	    for file in "$recipientDir"/*; do
+		##### Read first line of each file
+		recFileLine="$(head -n1 "$file")" && vbm "STATUS:Checking if pubkey:\"$recFileLine\"";
+		##### check if first line is a valid pubkey
+		if checkAgePubkey "$recFileLine" && \
+			( validateInput "$recFileLine" "ssh_pubkey" || validateInput "$recFileLine" "age_pubkey"); then
+		    ###### T: add candidate pubkey to candRecPubKeysValid
+		    candRecPubKeysValid+=("$recFileLine") && vbm "STATUS:RecDir pubkey is valid pubkey:\"$recFileLine\"";
+		else
+		    ###### F: throw warning;
+		    yell "ERROR:Invalid recipient file detected. Not modifying recipient list."
+		    updateRecipients="false";
+		fi;
+	    done
+	    #### Write updated recPubKeysValid array to recPubKeysValid if no failure detected
+	    if ! [[ "$updateRecipients" = "false" ]]; then
+		recPubKeysValid=("${candRecPubKeysValid[@]}") && vbm "STATUS:Wrote candRecPubkeysValid to recPubKeysValid:\"${recPubKeysValid[*]}\"";
+	    fi;
 	else
-	    yell "WARNING:Specified temporary working directory not valid:$OPTION_TMPDIR";
-	    exit 1;
-	fi
-    fi
-
-    ## Set DIR_TMP_PARENT to default or fallback otherwise
-    if [[ -d "$DIR_TMP_DEFAULT" ]]; then
-	DIR_TMP_PARENT="$DIR_TMP_DEFAULT";
-    elif [[ -d /tmp ]]; then
-	yell "WARNING:/dev/shm not available. Falling back to /tmp .";
-	DIR_TMP_PARENT="/tmp";
-    else
-	yell "ERROR:No valid working directory available. Exiting.";
-	exit 1;
-    fi
+	    yell "ERROR:$0:Recipient directory $argRecDir does not exist. Exiting."; exit 1;
+	fi;
+    fi;
+    # Handle case if '-R' set but '-e' not set
+    if [[ ! "$OPTION_ENCRYPT" = "true" ]] && [[ "$OPTION_RECDIR" = "true" ]]; then
+	yell "ERROR: \\'-R\\' is set but \\'-e\\' is not set."; fi;
+} # Update recPubKeysValid with argRecDir
+magicParseRecipientArgs() {
+    # Desc: Parses recipient arguments specified by '-r' option
+    # Input:  vars: OPTION_ENCRYPT from processArguments()
+    #         arry: argRecPubKeys from processArguments()
+    # Output: vars: CMD_ENCRYPT, CMD_ENCRYPT_SUFFIX
+    #         arry: recPubKeysValid, recPubKeysValidStatic
+    # Depends: checkapp(), checkAgePubkey(), validateInput(), processArguments()
+    local recipients
 
-    ## Set DIR_TMP using DIR_TMP_PARENT and nonce (SCRIPT_TIME_START)
-    DIR_TMP="$DIR_TMP_PARENT"/"$SCRIPT_TIME_START""..bkgpslog" && vbm "DEBUG:Set DIR_TMP to:$DIR_TMP"; # Note: removed at end of main().
-    
-    # Set output encryption and compression option strings
-    if [[ "$OPTION_ENCRYPT" = "true" ]]; then # Check if encryption option active.
+    # Check if encryption option active.
+    if [[ "$OPTION_ENCRYPT" = "true" ]] && [[ "$OPTION_RECIPIENTS" = "true" ]]; then 
 	if checkapp age; then # Check that age is available.
-	    for pubkey in "${recPubKeys[@]}"; do # Validate recipient pubkey strings by forming test message
-		vbm "DEBUG:Testing pubkey string:$pubkey"
-		if echo "butts" | age -a -r "$pubkey" 1>/dev/null; then
+	    for pubkey in "${argRecPubKeys[@]}"; do # Validate recipient pubkey strings by forming test message
+		vbm "DEBUG:Testing pubkey string:$pubkey";
+		if checkAgePubkey "$pubkey" && \
+			( validateInput "$pubkey" "ssh_pubkey" || validateInput "$pubkey" "age_pubkey"); then
 		    #### Form age recipient string
-		    recipients="$recipients""-r $pubkey ";
+		    recipients="$recipients""-r '$pubkey' ";
 		    vbm "STATUS:Added pubkey for forming age recipient string:""$pubkey";
 		    vbm "DEBUG:recipients:""$recipients";
 		    #### Add validated pubkey to recPubKeysValid array
 		    recPubKeysValid+=("$pubkey") && vbm "DEBUG:recPubkeysValid:pubkey added:$pubkey";
 		else
 		    yell "ERROR:Exit code ""$?"". Invalid recipient pubkey string. Exiting."; exit 1;
-		fi
+		fi;
 	    done
-	    vbm "DEBUG:Finished processing recPubKeys array";
+	    vbm "DEBUG:Finished processing argRecPubKeys array";
+	    vbm "STATUS:Array of validated pubkeys:${recPubKeysValid[*]}";
+	    recPubKeysValidStatic=("${recPubKeysValid[@]}"); # Save static image of pubkeys validated by this function
 
 	    ##  Form age command string
-	    CMD_ENCRYPT="age ""$recipients ";
-	    CMD_ENCRYPT_SUFFIX=".age";
+	    CMD_ENCRYPT="age ""$recipients " && vbm "CMD_ENCRYPT:$CMD_ENCRYPT";
+	    CMD_ENCRYPT_SUFFIX=".age" && vbm "CMD_ENCRYPT_SUFFIX:$CMD_ENCRYPT_SUFFIX";
 	else
 	    yell "ERROR:Encryption enabled but \"age\" not found. Exiting."; exit 1;
-	fi
+	fi;
     else
-	CMD_ENCRYPT="tee /dev/null ";
-	CMD_ENCRYPT_SUFFIX="";
+	CMD_ENCRYPT="tee /dev/null " && vbm "CMD_ENCRYPT:$CMD_ENCRYPT";
+	CMD_ENCRYPT_SUFFIX="" && vbm "CMD_ENCRYPT_SUFFIX:$CMD_ENCRYPT_SUFFIX";
 	vbm "DEBUG:Encryption not enabled."
-    fi
+    fi;
+    # Catch case if '-e' is set but '-r' or '-R' is not
+    if [[ "$OPTION_ENCRYPT" = "true" ]] && [[ ! "$OPTION_RECIPIENTS" = "true" ]]; then
+	yell "ERROR:\\'-e\\' set but no \\'-r\\' or \\'-R\\' set."; exit 1; fi;
+    # Catch case if '-r' or '-R' set but '-e' is not
+    if [[ ! "$OPTION_ENCRYPT" = "true" ]] && [[ "$OPTION_RECIPIENTS" = "true" ]]; then
+	yell "ERROR:\\'-r\\' or \\'-R\\' set but \\'-e\\' is not set."; exit 1; fi; 
+} # Populate recPubKeysValid with argRecPubKeys; form encryption cmd string and filename suffix
+magicParseCompressionArg() {
+    # Desc: Parses compression arguments specified by '-c' option
+    # Input:  vars: OPTION_COMPRESS
+    # Output: CMD_COMPRESS, CMD_COMPRESS_SUFFIX
+    # Depends: checkapp(), vbm(), gzip, 
     if [[ "$OPTION_COMPRESS" = "true" ]]; then # Check if compression option active
 	if checkapp gzip; then # Check if gzip available
-	    CMD_COMPRESS="gzip ";
-	    CMD_COMPRESS_SUFFIX=".gz";
+	    CMD_COMPRESS="gzip " && vbm "CMD_COMPRESS:$CMD_COMPRESS";
+	    CMD_COMPRESS_SUFFIX=".gz" && vbm "CMD_COMPRESS_SUFFIX:$CMD_COMPRESS_SUFFIX";
 	else
 	    yell "ERROR:Compression enabled but \"gzip\" not found. Exiting."; exit 1;
 	fi
     else
-	CMD_COMPRESS="tee /dev/null ";
-	CMD_COMPRESS_SUFFIX="";
+	CMD_COMPRESS="tee /dev/null " && vbm "CMD_COMPRESS:$CMD_COMPRESS";
+	CMD_COMPRESS_SUFFIX="" && vbm "CMD_COMPRESS_SUFFIX:$CMD_COMPRESS_SUFFIX";
 	vbm "DEBUG:Compression not enabled.";
-    fi
+    fi    
+} # Form compression cmd string and filename suffix
+magicInitWorkingDir() {
+    # Desc: Determine temporary working directory from defaults or user input
+    # Usage: magicInitWorkignDir
+    # Input:  vars: OPTION_TEMPDIR, argTempDirPriority, DIR_TMP_DEFAULT
+    # Input:  vars: SCRIPT_TIME_START
+    # Output: vars: DIR_TMP
+    # Depends: processArguments(), vbm(), yell()
+    # Parse '-t' option (user-specified temporary working dir)
+    ## Set DIR_TMP_PARENT to user-specified value if specified
+    local DIR_TMP_PARENT
+    
+    if [[ "$OPTION_TMPDIR" = "true" ]]; then
+	if [[ -d "$argTempDirPriority" ]]; then
+	    DIR_TMP_PARENT="$argTempDirPriority"; 
+	else
+	    yell "WARNING:Specified temporary working directory not valid:$argTempDirPriority";
+	    exit 1; # Exit since user requires a specific temp dir and it is not available.
+	fi;
+    else
+    ## Set DIR_TMP_PARENT to default or fallback otherwise
+	if [[ -d "$DIR_TMP_DEFAULT" ]]; then
+	    DIR_TMP_PARENT="$DIR_TMP_DEFAULT";
+	elif [[ -d /tmp ]]; then
+	    yell "WARNING:$DIR_TMP_DEFAULT not available. Falling back to /tmp .";
+	    DIR_TMP_PARENT="/tmp";
+	else
+	    yell "ERROR:No valid working directory available. Exiting.";
+	    exit 1;
+	fi
+    fi;
+    ## Set DIR_TMP using DIR_TMP_PARENT and nonce (SCRIPT_TIME_START)
+    DIR_TMP="$DIR_TMP_PARENT"/"$SCRIPT_TIME_START""..bkgpslog" && vbm "DEBUG:Set DIR_TMP to:$DIR_TMP"; # Note: removed at end of main().    
+} # Sets working dir
+magicParseCustomTTL() {
+    # Desc: Set user-specified TTLs for buffer and script
+    # Input: vars: argCustomBufferTTL (integer), argCustomScriptTTL_TE (string)
+    # Input: vars: OPTION_CUSTOM_BUFFERTTL, OPTION_CUSTOM_SCRIPTTTL
+    # Input: vars: BUFFER_TTL (integer), SCRIPT_TTL_TE (string)
+    # Output: BUFFER_TTL (integer), SCRIPT_TTL_TE (string)
+    # Depends validateInput(), showUsage(), yell
+
+    # React to '-b, --buffer-ttl' option
+    if [[ "$OPTION_CUSTOM_BUFFERTTL" = "true" ]]; then
+	## T: Check if argCustomBufferTTL is an integer
+	if validateInput "$argCustomBufferTTL" "integer"; then
+	    ### T: argCustomBufferTTL is an integer
+	    BUFFER_TTL="$argCustomBufferTTL";
+	else
+	    ### F: argcustomBufferTTL is not an integer
+	    yell "ERROR:Invalid integer argument for custom buffer time-to-live."; showUsage; exit 1;
+	fi;
+	## F: do not change BUFFER_TTL
+    fi;
+    
+    # React to '-B, --script-ttl' option
+    if [[ "$OPTION_CUSTOM_SCRIPTTTL_TE" = "true" ]]; then
+	## T: Check if argCustomScriptTTL is a time element (ex: "day", "hour")
+	if validateInput "$argCustomScriptTTL" "time_element"; then
+	    ### T: argCustomScriptTTL is a time element
+	    SCRIPT_TTL_TE="$argCustomScriptTTL";
+	else
+	    ### F: argcustomScriptTTL is not a time element
+	    yell "ERROR:Invalid time element argument for custom script time-to-live."; showUsage; exit 1;
+	fi;
+	## F: do not change SCRIPT_TTL_TE
+    fi;    
+} # Sets custom script or buffer TTL if specified
+
+
+main() {
+    # Process arguments
+    processArguments "$@";
+    ## Act upon arguments
+    ### Determine working directory
+    magicInitWorkingDir; # Sets DIR_TMP from argTempDirPriority
+    ### Set output encryption and compression option strings
+    #### React to "-r" ("encryption recipients") option
+    magicParseRecipientArgs; # Updates recPubKeysValid, CMD_ENCRYPT[_SUFFIX] from argRecPubKeys
+    #### React to "-c" ("compression") option
+    magicParseCompressionArg; # Updates CMD_COMPRESS[_SUFFIX]
+    #### React to "-R" ("recipient directory") option
+    magicParseRecipientDir; # Updates recPubKeysValid
+    #### React to custom buffer and script TTL options ("-b", "-B")
+    magicParseCustomTTL; # Sets custom SCRIPT_TTL_TE and/or BUFFER_TTL if specified
 
-    # Check that critical apps and dirs are available, displag missing ones.
-    if ! checkapp gpspipe tar && ! checkdir "$DIR_OUT" "/dev/shm"; then
+    # Check that critical apps and dirs are available, display missing ones.
+    if ! checkapp gpspipe tar && ! checkdir "$DIR_OUT" "DIR_TMP"; then
 	yell "ERROR:Critical components missing.";
 	displayMissing; yell "Exiting."; exit 1; fi
 
-    # Set script lifespan
-    setScriptTTL "$SCRIPT_TTL"; # seconds until next new SCRIPT_TTL (ex: "day" or "hour")
+    # Set script lifespan (SCRIPT_TTL from SCRIPT_TTL_TE)
+    magicSetScriptTTL "$SCRIPT_TTL_TE";
+    ## Note: SCRIPT_TTL_TE is time element string (ex: "day") while SCRIPT_TTL is integer seconds
 
-    # File name substring: encoded bufferTTL
-    bufferTTL_STR="$(timeDuration $BUFFER_TTL)";
+    # File name substring (ISO-8601 duration from BUFFER_TTL)
+    bufferTTL_STR="$(timeDuration "$BUFFER_TTL")";
 
     # Init temp working dir
     try mkdir "$DIR_TMP" && vbm "DEBUG:Working dir creatd at:$DIR_TMP";
@@ -866,47 +1321,24 @@ main() {
     checkMakeTar "$PATHOUT_TAR" && vbm "DEBUG:Confirmed or Created to be a tar:$PATHOUT_TAR";
     ## Append VERSION file to PATHOUT_TAR
     magicWriteVersion;
-    
-    # Record gps data until script lifespan ends
-    declare debugCounter; debugCounter="0"; # set debug counter
-    while [[ "$SECONDS" -lt "$scriptTTL" ]]; do
-	timeBufferStart="$(dateTimeShort)"; # Note start time
-	# Determine file paths (time is start of buffer period)
-	FILEOUT_BASENAME="$timeBufferStart""--""$bufferTTL_STR""..""$SCRIPT_HOSTNAME""_location" && vbm "STATUS:Set FILEOUT_BASENAME to:$FILEOUT_BASENAME";
-	## Files saved to DIR_TMP
-	FILEOUT_NMEA="$FILEOUT_BASENAME".nmea"$CMD_COMPRESS_SUFFIX""$CMD_ENCRYPT_SUFFIX" && vbm "STATUS:Set FILEOUT_NMEA to:$FILEOUT_NMEA";
-	FILEOUT_GPX="$FILEOUT_BASENAME".gpx"$CMD_COMPRESS_SUFFIX""$CMD_ENCRYPT_SUFFIX" && vbm "STATUS:Set FILEOUT_GPX to:$FILEOUT_GPX";
-	FILEOUT_KML="$FILEOUT_BASENAME".kml"$CMD_COMPRESS_SUFFIX""$CMD_ENCRYPT_SUFFIX" && vbm "STATUS:Set FILEOUT_KML to:$FILEOUT_KML";
-	PATHOUT_NMEA="$DIR_TMP"/"$FILEOUT_NMEA" && vbm "STATUS:Set PATHOUT_NMEA to:$PATHOUT_NMEA";
-	PATHOUT_GPX="$DIR_TMP"/"$FILEOUT_GPX" && vbm "STATUS:Set PATHOUT_GPX to:$PATHOUT_GPX";
-	PATHOUT_KML="$DIR_TMP"/"$FILEOUT_KML" && vbm "STATUS:Set PATHOUT_KML to:$PATHOUT_KML";
-	## Files saved to disk (DIR_OUT)
-	### one file per day (Ex: "20200731..hostname_location.[.gpx.gz].tar")
-	PATHOUT_TAR="$DIR_OUT"/"$(dateShort)".."$SCRIPT_HOSTNAME""_location""$CMD_COMPRESS_SUFFIX""$CMD_ENCRYPT_SUFFIX".tar && \
-	    vbm "STATUS:Set PATHOUT_TAR to:$PATHOUT_TAR";
-	# Define GPS conversion commands
-	CMD_CONV_NMEA="tee /dev/null " && vbm "STATUS:Set CMD_CONV_NMEA to:$CMD_CONV_NMEA"; # tee as passthrough
-	CMD_CONV_GPX="gpsbabel -i nmea -f - -o gpx -F - " && vbm "STATUS:Set CMD_CONV_GPX to:$CMD_CONV_GPX"; # convert NMEA to GPX
-	CMD_CONV_KML="gpsbabel -i nmea -f - -o kml -F - " && vbm "STATUS:Set CMD_CONV_KML to:$CMD_CONV_KML"; # convert NMEA to KML
-	# Fill Bash variable buffer
-	bufferBash="$(timeout "$BUFFER_TTL""s" gpspipe -r)" && vbm "STATUS:Successfully filled bufferBash variable with gpspipe data."; # Record gpspipe nmea data to buffer for bufferTTL seconds
-	# Process bufferBash, save secured chunk set to DIR_TMP
-	vbm "STATUS:Beginning to save data to $DIR_TMP";
-	magicWriteBuffer &
-	# Append each secured chunk in memory dir (DIR_TMP) to file on disk (PATHOUT_TAR in DIR_OUT)
-	vbm "STATUS:DIR_TMP     :$DIR_TMP";
-	vbm "STATUS:PATHOUT_TAR :$PATHOUT_TAR";
-	vbm "STATUS:PATHOUT_NMEA:$PATHOUT_NMEA";
-	vbm "STATUS:PATHOUT_GPX:$PATHOUT_GPX";
-	vbm "STATUS:PATHOUT_KML:$PATHOUT_KML";
-
-	# Reset buffer and filenames
-	unset bufferBash FILEOUT_BASENAME PATHOUT_NMEA PATHOUT_GPX PATHOUT_KML PATHOUT_TAR timeBufferStart;
-	vbm "DEBUG:Completed buffer session $debugCounter ." 1>&2;
-	((debugCounter++))
-    done
 
-    # Remove DIR_TMP
+    # Define GPS conversion commands
+    CMD_CONV_NMEA="tee /dev/null " && vbm "STATUS:Set CMD_CONV_NMEA to:$CMD_CONV_NMEA"; # tee as passthrough
+    CMD_CONV_GPX="gpsbabel -i nmea -f - -o gpx -F - " && vbm "STATUS:Set CMD_CONV_GPX to:$CMD_CONV_GPX"; # convert NMEA to GPX
+    CMD_CONV_KML="gpsbabel -i nmea -f - -o kml -F - " && vbm "STATUS:Set CMD_CONV_KML to:$CMD_CONV_KML"; # convert NMEA to KML
+
+    # MAIN LOOP:Record gps data until script lifespan ends
+    timeBufferFirstNS="$(timeEpochNS)"; bufferRound=0; BUFFER_TTL_ADJ_FLOAT="10.0";
+    while [[ "$SECONDS" -lt "$SCRIPT_TTL" ]]; do
+	magicParseRecipientDir;
+	magicGatherWriteBuffer &
+	sleep "$BUFFER_TTL_ADJ_FLOAT";
+	((bufferRound++));
+	magicBufferSleepPID; # Calculates BUFFER_TTL_ADJ from BUFFER_TTL given buffer expected start time vs. actual
+    done    
+
+    # Cleanup
+    ## Remove DIR_TMP
     try rm -r "$DIR_TMP";
 
     vbm "STATUS:Main function finished.";