Revonzy Mini Shell

#!/bin/sh
grep=grep
unset _EXECOPT _GREPOPT
case $0 in
  */*)
    dir=${0%/*}
    if test -x "$dir/grep"; then
      PATH=$dir:$PATH
      grep=grep
    fi;;
esac
if [ "$GREP_LEGACY_EGREP_FGREP_PS" = 1 ]; then
  _EXECOPT="-a egrep"
else
  _GREPOPT=-E
fi
exec $_EXECOPT $grep $_GREPOPT "$@"