$ whereis true
true: /bin/true /usr/share/man/man1/true.1.bz2 /usr/share/man/man1p/true.1p.bz2
$

#!/usr/bin/bash
 
wd=$(dirname "$0")
pyth=$(which python)
latex=$(which latex)
xelatex=$(which xelatex)
mkindex=$(which makeindex)

input="$wd/ALMSGrammar.txt"
texfile="$wd/build/ALMSGrammar.tex"

ARGS="$input $texfile"

while getopts "isc:" opt; do
  case $opt in
    i)
        ARGS="$ARGS --indices"
        INDICES=1
      ;;
    s)
      ARGS="$ARGS --label-slots"
      ;;
    c)
      ARGS="$ARGS --categories $OPTARG"
      ;;
    \?)
      echo "Invalid option: -$OPTARG" >&2
      echo "Usage:" >&2
      echo -e "   -i \tgenerate indices" >&2
      echo -e "   -s \tlabel slots" >&2
      exit 1
      ;;
  esac
done

# Note $ARGS is not in quotes and MUST NOT be in quotes.
# The spaces cause the arguments to split apart where you want them to.
# "$ARGS" would make it one giant argument.
$pyth "$wd/texify_grammar.py" $ARGS 

pushd "$wd/build"

# This is how you do string comparison!  -z means "if the string is empty".
# See http://tldp.org/LDP/abs/html/refcards.html#AEN22167 for details
# on more kinds of comparison.
if [ ! -z "$INDICES" ]
then
  "$latex" ALMSGrammar.tex
  "$mkindex" tokens
  "$mkindex" categories
  "$mkindex" todo
  "$latex" ALMSGrammar.tex
fi

"$xelatex" ALMSGrammar.tex
popd

mv "$wd/build/ALMSGrammar.pdf" "$wd"
open "$wd/ALMSGrammar.pdf"