boy is this some extremely specific shit huh

convert_mdb.sh

#!/usr/bin/env bash

######################################################################
#                                                                    #
#                         da config zone                             #
#                                                                    #
######################################################################
# where to put all the converted files, relative to where this script lives
OUTPUT_DIR="output-dir"

# the good file extension we will convert stuff to (without the .)
TARGET_EXT=mdb

# file extensions that we'll look for to change to TARGET_EXT, no ., separated by spaces
CONVERTIBLE_EXTS="chg dat horse butt"

# name of the .jar converter tool file to use, in the same directory as this script
JAR_TOOL="client-0.0.5.jar"

# url to download the jar tool if needed, used if JAR_TOOL above is not found
JAR_DOWNLOAD="https://search.maven.org/remotecontent?filepath=com/rebasedata/client/0.0.5/client-0.0.5.jar"

######################################################################
#                                                                    #
#                     end of da config zone                          #
#                                                                    #
######################################################################


# hello, it me
mydir="$(cd "$(dirname "$0")" && pwd)"
cd "$mydir"

# check for java, die if missing
if ! type java > /dev/null; then
  echo "java is not installed! go get a JRE or JDK!" 1>&2 
  exit 1
fi

# check if the output dir already exists, die if it does so we don't overwrite anything
if [ -d $OUTPUT_DIR ]; then
  echo "Output directory \`$mydir/$OUTPUT_DIR\` already exists!" 1>&2 
  echo "Exiting before we overwrite something." 1>&2 
  exit 1
fi

# check for the conversion tool, download if missing
if [ ! -f "$mydir/$JAR_TOOL" ]; then
  echo "$JAR_TOOL is missing, downloading a new one..."
  curl -L -# -o "$mydir/$JAR_TOOL" $JAR_DOWNLOAD
fi

# assemble the find command based on extensions to change
arg_str=""
first=true
for ext in $CONVERTIBLE_EXTS; do
  arg=""
  if ! $first; then
    arg="$arg -o "
  fi 
  first=false

  arg="$arg-iname \\*.$ext"
  arg_str="$arg_str$arg"
done
find_cmd="find \"$mydir\" -maxdepth 1 -type f $arg_str"

# rename all the files in the current dir with the given extensions to the target extension
eval $find_cmd | while read -r fp ; do
  fp_escaped=$(printf %q "$fp")
  target_fp="$mydir/$(basename "$fp" .${fp_escaped##*.}).$TARGET_EXT"
  echo "renaming $fp -> $target_fp"
  mv "$fp" "$target_fp"
done

# create output dir, temp dir
tmpdir="$mydir/tmpout"
mkdir -p "$tmpdir"
mkdir "$mydir/$OUTPUT_DIR"

# iterate over the mdb files
eval "find \"$mydir\" -maxdepth 1 -type f -iname \\*.mdb" | while read -r infile ; do
  # we can't control the output filenames
  # so, convert to csv files in a temp directory
  filename=$(basename "$infile" .${infile##*.})
  mytmp="$tmpdir/$filename"
  mkdir "$mytmp"
  echo "converting $filename..."
  java -jar "$mydir/$JAR_TOOL" convert --output-format=csv "$infile" "$mytmp" > /dev/null

  # move all the temp csv files to the real output dir, 
  # while renaming using the original mdb file name.
  # we ignore the .Columns because they seem pointless, really
  mytmp_escaped=$(printf %q "$mytmp")
  eval "find $mytmp_escaped -maxdepth 1 -type f -iname \\*.csv" | while read -r infile ; do
    infile_base=$(basename "$infile")
    mv "$infile" "$mydir/$OUTPUT_DIR/$filename-$infile_base"
  done
done

rm -r "$tmpdir"

echo "done!"