fix(user/bk-copy-rand-music):Follow direct symlinks to files

[BK-2020-03.git] / unitproc / bkt-writeArg

#!/bin/bash

# Desc: Template function to write data supplied as argument

yell() { echo "$0: $*" >&2; } # Yell, Die, Try Three-Fingered Claw technique; # Ref/Attrib: https://stackoverflow.com/a/25515370
die() { yell "$*"; exit 111; }
try() { "$@" || die "cannot $*"; }
writeArg(){
    # Desc: Writes first argument with subsequent arguments as options
    # Usage: writeArg "$(echo "Data to be written.")" [output path] ([cmd1] [cmd2] [cmd3] [cmd4]...)
    # Input: arg1: data to be written
    #        arg2: output path
    #        arg3+: command strings (ex: "gpsbabel -i nmea -f - -o kml -F - ")
    # Output: file written to disk
    # Example: decrypt multiple large files in parallel
    #          writeArg "$(cat /tmp/largefile1.gpg)" /tmp/largefile1 "gpg --decrypt" &
    #          writeArg "$(cat /tmp/largefile2.gpg)" /tmp/largefile2 "gpg --decrypt" &
    #          writeArg "$(cat /tmp/largefile3.gpg)" /tmp/largefile3 "gpg --decrypt" &
    # Depends: bash 5
    
    # Set command strings
    if ! [ -z "$3" ]; then CMD1="$3"; else CMD1="tee /dev/null "; fi # command string 1
    if ! [ -z "$4" ]; then CMD2="$4"; else CMD2="tee /dev/null "; fi # command string 2
    if ! [ -z "$5" ]; then CMD3="$5"; else CMD3="tee /dev/null "; fi # command string 3
    if ! [ -z "$6" ]; then CMD4="$6"; else CMD4="tee /dev/null "; fi # command string 4

    # Debug
    yell "CMD1:$CMD1"
    yell "CMD2:$CMD2"
    yell "CMD3:$CMD3"
    yell "CMD4:$CMD4"
    # Write
    echo "$1" | $CMD1 | $CMD2 | $CMD3 | $CMD4 > "$2";

} # Write Bash var to file

#==BEGIN sample code==
myFile="/tmp/$(date +%s)..original"
echo "how are you doing?" > "$myFile"
myVAR="$(cat $myFile)"
writeArg "$myVAR" "$myFile..LOUD_CHILD" "tee /tmp/cloneityclone " "tr '[:lower:]' '[:upper:]'"
#==END sample code==

# Author: Steven Baltakatei Sandoval
# License: GPLv3+