feat(bkgpslog):Consolidate tar validation/creation

Consolidate how output tar file is validated (if it already exists)
and/or created. checkMakeTar() function added for this purpose.

Add checkMakeTar() in `magicWriteBuffer()` in case output tar file is
deleted between writes.

diff --git a/exec/bkgpslog b/exec/bkgpslog
index c7cae3658a928b3415c94899c941e7cb7b498e57..c66a0e5b2823491e0c0a55879b7b006e6e00974b 100755 (executable)
--- a/exec/bkgpslog
+++ b/exec/bkgpslog
@@ -612,6 +612,32 @@ setScriptTTL() {
        yell "ERROR:Invalid argument for setScriptTTL function."; exit 1;
     fi
 } # Seconds until next (day|hour).
+checkMakeTar() {
+    # Desc: Checks that a valid tar archive exists, creates one otherwise
+    # Usage: checkMakeTar [ path ]
+    # Input: arg1: path of tar archive
+    # Output: exit code 0 (even if tar had to be created)
+    # Depends: try, tar, date
+    local PATH_TAR="$1"
+
+    # Check if file is a valid tar archive
+    if tar --list --file="$PATH_TAR" 1>/dev/null 2>&1; then
+       ## T1: return success
+       return 0;
+    else
+       ## F1: Check if file exists
+       if [[ -f "$PATH_TAR" ]]; then
+           ### T: Rename file
+           try mv "$PATH_TAR" "$PATH_TAR""--broken--""$(date +%Y%m%dT%H%M%S)";
+       else
+           ### F: -
+           :
+       fi
+       ## F2: Create tar archive, return 0
+       try tar --create --file="$PATH_TAR" --files-from=/dev/null;
+       return 0;
+    fi
+} # checks if arg1 is tar; creates one otherwise
 appendArgTar(){
     # Desc: Writes first argument to temporary file with arguments as options, then appends file to tar
     # Usage: writeArg "$(echo "Data to be written.")" [name of file to be inserted] [tar path] [temp dir] ([cmd1] [cmd2] [cmd3] [cmd4]...)
@@ -663,9 +689,16 @@ appendArgTar(){
 } # Append Bash var to file appended to Tar archive
 magicWriteBuffer() {
     # 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="${FUNCNAME[0]}";
     wait; # Wait to avoid collision with older magicWriteBuffer() instances (see https://www.tldp.org/LDP/abs/html/x9644.html )
-    yell "DEBUG:STATUS:$FN:Started magicWriteBuffer().";
+    vbm "DEBUG:STATUS:$FN:Started magicWriteBuffer().";
+
+    # Check that PATHOUT_TAR is a tar. Rename old and create empty one otherwise.
+    checkMakeTar "$PATHOUT_TAR"
+
+    # 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" "$CMD_ENCRYPT"; # Write KML file
@@ -760,30 +793,14 @@ main() {
     ## Define output tar path (note: each day gets *one* tar file (Ex: "20200731..hostname_location.[.gpx.gz].tar"))
     PATHOUT_TAR="$DIR_OUT"/"$(dateShort)".."$SCRIPT_HOSTNAME""_location""$CMD_COMPRESS_SUFFIX""$CMD_ENCRYPT_SUFFIX".tar && \
        vbm "STATUS:Set PATHOUT_TAR to:$PATHOUT_TAR";
-    ## Write bkgpslog version to DIR_TMP/VERSION
+    ## Generate VERSION file
     FILEOUT_VERSION="$(dateTimeShort)..VERSION";
     PATHOUT_VERSION="$DIR_TMP"/"$FILEOUT_VERSION";
     echo "$(dateTimeShort):$(basename "$0")"" Version:""$SCRIPT_VERSION" >> "$PATHOUT_VERSION" && vbm "DEBUG:VERSION created:$PATHOUT_VERSION";
-    ## Check if PATHOUT_TAR already exists.
-    if [[ -f "$PATHOUT_TAR" ]]; then
-       vbm "STATUS:Output tar already exists:$PATHOUT_TAR";
-       ### Check if preexisting tar is appendable.
-       FILEOUT_APPENDTEST="$(dateTimeShort)..RESUMING_LOGGING_SESSION.txt";
-       PATHOUT_APPENDTEST="$DIR_TMP"/"$FILEOUT_APPENDTEST" && \
-           vbm "DEBUG:Set PATHOUT_APPENDTEST to:$PATHOUT_APPENDTEST";
-       echo "$(dateTimeShort):""$(basename "$0")"" version $SCRIPT_VERSION resuming logging session." >> "$PATHOUT_APPENDTEST" && \
-           vbm "DEBUG:""$PATHOUT_APPENDTEST"" created.";
-       if ! tar --append --directory="$DIR_TMP" --file="$PATHOUT_TAR" "$FILEOUT_APPENDTEST"; then
-           ### If not appendable, label tar broken, move tar, proceed.
-           mv "$PATHOUT_TAR" "${PATHOUT_TAR%.*}""-broken$(dateTimeShort)".tar && \
-               vbm "DEBUG:tar not writable, moving out of the way $PATHOUT_TAR";
-       fi
-    else
-       vbm "STATUS:Output tar does not already exist. Creating:$PATHOUT_TAR";
-       ### If (no preexisting|appendable) tar found, create empty tar archive at PATHOUT_TAR
-       try tar --create --directory="$DIR_TMP" --file="$PATHOUT_TAR" --files-from=/dev/null && \
-           vbm "DEBUG:Empty tar created at:$PATHOUT_TAR";
-    fi 
+
+    ## Check that PATHOUT_TAR is a tar. Rename old and create empty one otherwise.
+    checkMakeTar "$PATHOUT_TAR" && vbm "DEBUG:Confirmed or Created to be a tar:$PATHOUT_TAR";
+
     ## Append VERSION file to PATHOUT_TAR
     try tar --append --directory="$DIR_TMP" --file="$PATHOUT_TAR" "$FILEOUT_VERSION" && \
        vbm "DEBUG:VERSION added to $PATHOUT_TAR";

diff --git a/exec/bkgpslog-plan.org b/exec/bkgpslog-plan.org
index 7eb5514b65bff95a140749317af2638c65313261..c494758efaca14438b74d66427d7fc2fd28c6763 100644 (file)
--- a/exec/bkgpslog-plan.org
+++ b/exec/bkgpslog-plan.org
@@ -16,6 +16,16 @@ used to delay processing until a specified job completes. The ~wait~
 command will pause script execution until all backgrounded processes
 complete.
 2020-07-02T16:03Z; bktei> Added ~wait~.
+** DONE Rewrite tar initialization function
+   CLOSED: [2020-07-02 Thu 17:23]
+2020-07-02T17:23Z; bktei> Simplify tar initialization function so
+VERSION file is used to test appendability of tar as well as to mark
+when a new session is started.
+** DONE Consolidate tar checking/creation into function
+   CLOSED: [2020-07-02 Thu 18:33]
+2020-07-02T18:33Z; bktei> Simplify how the output tar file's existence
+is checked and its status as a valid tar file is validated. This was
+done using a new function ~checkMakeTar~.
 * bkgpslog narrative
 ** Initialize environment
 *** Init variables