unitproc/bktemp-appendFileTar

   1 #!/bin/bash
   2 # Desc: Append [processed] file to tar
   3
   4 yell() { echo "$0: $*" >&2; } # Yell, Die, Try Three-Fingered Claw technique; # Ref/Attrib: https://stackoverflow.com/a/25515370
   5 die() { yell "$*"; exit 111; }
   6 try() { "$@" || die "cannot $*"; }
   7 appendFileTar(){
   8     # Desc: Appends [processed] file to tar
   9     # Usage: appendFileTar [file path] [name of file to be inserted] [tar path] [temp dir] ([process cmd])
  10     # Version: 2.0.1
  11     # Input: arg1: path of file to be (processed and) written
  12     #        arg2: name to use for file inserted into tar
  13     #        arg3: tar archive path (must exist first)
  14     #        arg4: temporary working dir
  15     #        arg5: (optional) command string to process file (ex: "gpsbabel -i nmea -f - -o kml -F - ")
  16     # Output: file written to disk
  17     # Example: decrypt multiple large files in parallel
  18     #          appendFileTar /tmp/largefile1.gpg "largefile1" $HOME/archive.tar /tmp "gpg --decrypt" &
  19     #          appendFileTar /tmp/largefile2.gpg "largefile2" $HOME/archive.tar /tmp "gpg --decrypt" &
  20     #          appendFileTar /tmp/largefile3.gpg "largefile3" $HOME/archive.tar /tmp "gpg --decrypt" &
  21     # Depends: bash 5.0.3, tar 1.30, cat 8.30, yell()
  22     local fn fileName tarPath tmpDir
  23
  24     # Save function name
  25     fn="${FUNCNAME[0]}";
  26     #yell "DEBUG:STATUS:$fn:Started appendFileTar()."
  27
  28     # Set file name
  29     if ! [ -z "$2" ]; then fileName="$2"; else yell "ERROR:$fn:Not enough arguments."; exit 1; fi
  30     # Check tar path is a file
  31     if [ -f "$3" ]; then tarPath="$3"; else yell "ERROR:$fn:Tar archive arg not a file:$3"; exit 1; fi
  32     # Check temp dir arg
  33     if ! [ -z "$4" ]; then tmpDir="$4"; else yell "ERROR:$fn:No temporary working dir set."; exit 1; fi
  34     # Set command strings
  35     if ! [ -z "$5" ]; then cmd1="$5"; else cmd1="cat "; fi # command string
  36
  37     # Input command string
  38     cmd0="cat \"\$1\"";
  39
  40     # Write to temporary working dir
  41     eval "$cmd0 | $cmd1" > "$tmpDir"/"$fileName";
  42
  43     # Append to tar
  44     try tar --append --directory="$tmpDir" --file="$tarPath" "$fileName";
  45     #yell "DEBUG:STATUS:$fn:Finished appendFileTar()."
  46 } # Append [processed] file to Tar archive
  47
  48 #==BEGIN sample code==
  49 myTar="/tmp/$(date +%s).tar";
  50 myTmpDir="/dev/shm";
  51 try tar --create --file="$myTar" --files-from=/dev/null ;
  52 myFile="/tmp/$(date +%s)..original";
  53 echo "how are you doing?" > "$myFile";
  54 appendFileTar "$myFile" "$(date +%s)..LOUD_insidetar" "$myTar" "$myTmpDir" "tee /tmp/$(date +%s)..outsidetar | tr '[:lower:]' '[:upper:]'" && \
  55     echo "Inserted a processed version of $myFile into $myTar using temp dir $myTmpDir ";
  56 #==END sample code==
  57
  58 # Author: Steven Baltakatei Sandoval
  59 # License: GPLv3+