style(unitproc):appendFileTar():VAR_NAME to varName
[BK-2020-03.git] / 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: 1.0.6
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" $HOME/archive.tar /tmp "gpg --decrypt" &
22 # Depends: bash 5, tar 1, yell()
23 # Ref/Attrib: Using 'eval' to construct command strings https://askubuntu.com/a/476533
24
25 local fn fileName tarPath tmpDir cmd0 cmd1 cmd2 cmd3 cmd4
26
27 # Save function name
28 fn="${FUNCNAME[0]}";
29 #yell "DEBUG:STATUS:$fn:Finished appendArgTar()."
30
31 # Set file name
32 if ! [ -z "$2" ]; then fileName="$2"; else yell "ERROR:$fn:Not enough arguments."; exit 1; fi
33
34 # Check tar path is a file
35 if [ -f "$3" ]; then tarPath="$3"; else yell "ERROR:$fn:Tar archive arg not a file."; exit 1; fi
36
37 # Check temp dir arg
38 if ! [ -z "$4" ]; then tmpDir="$4"; else yell "ERROR:$fn:No temporary working dir set."; exit 1; fi
39
40 # Set command strings
41 if ! [ -z "$5" ]; then cmd1="$5"; else cmd1="cat "; fi # command string 1
42 if ! [ -z "$6" ]; then cmd2="$6"; else cmd2="cat "; fi # command string 2
43 if ! [ -z "$7" ]; then cmd3="$7"; else cmd3="cat "; fi # command string 3
44 if ! [ -z "$8" ]; then cmd4="$8"; else cmd4="cat "; fi # command string 4
45
46 # Input command
47 cmd0="echo \"\$1\""
48
49 # # Debug
50 # yell "DEBUG:STATUS:$fn:cmd0:$cmd0"
51 # yell "DEBUG:STATUS:$fn:cmd1:$cmd1"
52 # yell "DEBUG:STATUS:$fn:cmd2:$cmd2"
53 # yell "DEBUG:STATUS:$fn:cmd3:$cmd3"
54 # yell "DEBUG:STATUS:$fn:cmd4:$cmd4"
55 # yell "DEBUG:STATUS:$fn:fileName:$fileName"
56 # yell "DEBUG:STATUS:$fn:tarPath:$tarPath"
57 # yell "DEBUG:STATUS:$fn:tmpDir:$tmpDir"
58
59 # Write to temporary working dir
60 eval "$cmd0 | $cmd1 | $cmd2 | $cmd3 | $cmd4" > "$tmpDir"/"$fileName";
61
62 # Append to tar
63 try tar --append --directory="$tmpDir" --file="$tarPath" "$fileName";
64 #yell "DEBUG:STATUS:$fn:Finished appendArgTar()."
65 } # Append Bash var to file appended to Tar archive
66
67 #==BEGIN sample code==
68 myTar="/tmp/$(date +%s).tar";
69 myTmpDir="/dev/shm"
70 try tar --create --file="$myTar" --files-from=/dev/null ;
71 myVar="how are you doing?"
72 appendArgTar "$myVar" "$(date +%s)..LOUD_insidetar" "$myTar" "$myTmpDir" "tee /tmp/$(date +%s)..outsidetar " "tr '[:lower:]' '[:upper:]'" && \
73 echo "Created $myTar using $myTmpDir as temp working dir."
74 #==END sample code==
75
76 # Author: Steven Baltakatei Sandoval
77 # License: GPLv3+