brotlizpaq

#!/bin/bash
# usage: brotlizpaq a|c archive.zpaq INPUTFILES…
# a: append to existing archive, c: create (invokation of zpaqd)
# creates a valid zpaq archive and stores the files compressed with brotli
# needs path to brotli.cfg, brotli-dict, zpaqd
# and bro (https://github.com/google/brotli with usage as bro --quality 9 --input IN --output OUT.br)

# needs pcomp line as "pcomp ./brotli-helper ;" (copied from git or compiled from zpaqlpy test/brotli.py)
BROTLICFG="test/brotli.cfg"
ZPAQD="./zpaqd"
BRO="test/bro"
BROTLIDICT="test/brotli-dict"

set -euo pipefail
# -euxo pipefail to debug

if [ -z "$1" ] || [ "$1" == "-h" ] || [ "$1" == "--help" ]
  then
  echo "usage: $0 a|c archive.zpaq INPUTFILES…"
  exit
fi

# temp files must not contain a . (so invoke tmpfile instead of mktemp)
TMPCFG=`tempfile`.cfg
TMPHELPER=`tempfile`
TMPLOCK=`tempfile`
cat "$BROTLICFG" |  sed "s#pcomp ./brotli-helper ;#pcomp $TMPHELPER ;#g" > "$TMPCFG"
printf '#!/bin/sh\nTMPBR=`tempfile`.br\n' > "$TMPHELPER"
printf "\"$BRO\"" >> "$TMPHELPER"
echo ' --quality 9 --input "$1" --output "$TMPBR"' >> "$TMPHELPER"
printf "if [ -e \"$TMPLOCK\" ]\n" >> "$TMPHELPER"
printf 'then\n  printf "x" > "$2"  # no dict\n  cat "$TMPBR" >> "$2"\nelse\n' >> "$TMPHELPER"
printf "  cat \"$BROTLIDICT\" " >> "$TMPHELPER"
printf '"$TMPBR" > "$2"\n  touch ' >> "$TMPHELPER"
echo "\"$TMPLOCK\"" >> "$TMPHELPER"
printf 'fi\nrm "$TMPBR"' >> "$TMPHELPER"

chmod +x "$TMPHELPER"

rm "$TMPLOCK"
"$ZPAQD" "$1" "$TMPCFG" "$2" "${@:3}"
rm "$TMPHELPER" "$TMPCFG" "$TMPLOCK"