You cannot optimize integral division like this. You end up multiplying by 0, 1 or 2 instead of whole spectre of ratios.
#!/bin/sh
if [ -d QTfrontend ]; then
cd QTfrontend
else
if [ -d ../QTfrontend ]; then
cd ../QTfrontend
else
echo 'abort: Directory "QTfrontend" not found!' >&2
exit 1
fi
fi
if [ -z "$1" ]; then
OUTPUT_DIRECTORY="../doc/QTfrontend"
else
OUTPUT_DIRECTORY="$1"
fi
echo "Creating documentation for Qt-Frontend in $OUTPUT_DIRECTORY ..."
if [ $(which hg) ]; then
branch=$(hg identify -b)
rev=$(hg identify -rdefault -i)
export PROJECT_NUMBER="${branch} branch, ${rev}"
export OUTPUT_DIRECTORY
fi
doxygen
exit $?