unitproc/bktemp-appendArgTar

   1 #!/bin/bash
   2
   3 # Desc: Template function to write data supplied as argument
   4
   5 yell() { echo "$0: $*" >&2; } # Yell, Die, Try Three-Fingered Claw technique; # Ref/Attrib: https://stackoverflow.com/a/25515370
   6 die() { yell "$*"; exit 111; }
   7 try() { "$@" || die "cannot $*"; }
   8 appendArgTar(){
   9     # Desc: Writes first argument to temporary file with arguments as options, then appends file to tar
  10     # Usage: appendArgTar "$(echo "Data to be written.")" [name of file to be inserted] [tar path] [temp dir] ([cmd1] [cmd2] [cmd3] [cmd4]...)
  11     # Version: 1.0.4
  12     # Input: arg1: data to be written
  13     #        arg2: file name of file to be inserted into tar
  14     #        arg3: tar archive path (must exist first)
  15     #        arg4: temporary working dir
  16     #        arg5+: command strings (ex: "gpsbabel -i nmea -f - -o kml -F - ")
  17     # Output: file written to disk
  18     # Example: decrypt multiple large files in parallel
  19     #          appendArgTar "$(cat /tmp/largefile1.gpg)" "largefile1" $HOME/archive.tar /tmp "gpg --decrypt" &
  20     #          appendArgTar "$(cat /tmp/largefile2.gpg)" "largefile2" $HOME/archive.tar /tmp "gpg --decrypt" &
  21     #          appendArgTar "$(cat /tmp/largefile3.gpg)" "largefile3" $HOME/archive.tar /tmp "gpg --decrypt" &
  22     # Depends: bash 5
  23     # Ref/Attrib: Using 'eval' to construct command strings https://askubuntu.com/a/476533
  24
  25     # Save function name
  26     local FN="${FUNCNAME[0]}";
  27     #yell "DEBUG:STATUS:$FN:Finished appendArgTar()."
  28
  29     # Set file name
  30     if ! [ -z "$2" ]; then FILENAME="$2"; else yell "ERROR:$FN:Not enough arguments."; exit 1; fi
  31
  32     # Check tar path is a file
  33     if [ -f "$3" ]; then TAR_PATH="$3"; else yell "ERROR:$FN:Tar archive arg not a file."; exit 1; fi
  34
  35     # Check temp dir arg
  36     if ! [ -z "$4" ]; then TMP_DIR="$4"; else yell "ERROR:$FN:No temporary working dir set."; exit 1; fi
  37
  38     # Set command strings
  39     if ! [ -z "$5" ]; then CMD1="$5"; else CMD1="tee /dev/null "; fi # command string 1
  40     if ! [ -z "$6" ]; then CMD2="$6"; else CMD2="tee /dev/null "; fi # command string 2
  41     if ! [ -z "$7" ]; then CMD3="$7"; else CMD3="tee /dev/null "; fi # command string 3
  42     if ! [ -z "$8" ]; then CMD4="$8"; else CMD4="tee /dev/null "; fi # command string 4
  43
  44     # Input command
  45     CMD0="echo \"\$1\""
  46
  47     # # Debug
  48     # yell "DEBUG:STATUS:$FN:CMD0:$CMD0"
  49     # yell "DEBUG:STATUS:$FN:CMD1:$CMD1"
  50     # yell "DEBUG:STATUS:$FN:CMD2:$CMD2"
  51     # yell "DEBUG:STATUS:$FN:CMD3:$CMD3"
  52     # yell "DEBUG:STATUS:$FN:CMD4:$CMD4"
  53     # yell "DEBUG:STATUS:$FN:FILENAME:$FILENAME"
  54     # yell "DEBUG:STATUS:$FN:TAR_PATH:$TAR_PATH"
  55     # yell "DEBUG:STATUS:$FN:TMP_DIR:$TMP_DIR"
  56
  57     # Write to temporary working dir
  58     eval "$CMD0 | $CMD1 | $CMD2 | $CMD3 | $CMD4" > "$TMP_DIR"/"$FILENAME";
  59
  60     # Append to tar
  61     try tar --append --directory="$TMP_DIR" --file="$TAR_PATH" "$FILENAME";
  62     #yell "DEBUG:STATUS:$FN:Finished appendArgTar()."
  63 } # Append Bash var to file appended to Tar archive
  64
  65 #==BEGIN sample code==
  66 myTar="/tmp/$(date +%s).tar";
  67 try tar --create --file="$myTar" --files-from=/dev/null ;
  68 myVar="how are you doing?"
  69 appendArgTar "$myVar" "$(date +%s)..LOUD_insidetar" "$myTar" "/dev/shm" "tee /tmp/$(date +%s)..outsidetar " "tr '[:lower:]' '[:upper:]'"
  70 #==END sample code==
  71
  72 # Author: Steven Baltakatei Sandoval
  73 # License: GPLv3+