Using of variables in Git aliases

.gitconfig

# Simplify the similar aliases in .gitconfig by using variables instead of
# copying the same flags.

[alias]
  flags        = "!FLAG_LOG='--graph --decorate --find-renames --date-order'; \
                   FLAG_DIFF='--patch --stat --ignore-blank-lines';"
  glog         = "!git flags; git log $FLAG_LOG --name-status"
  gslog        = "!git flags; git log $FLAG_LOG --stat"
  slog         = "!git flags; git log $FLAG_LOG --date=short --format='%C(auto)%h%C(auto)%d %C(bold blue)%ad %an%n        %s%C(reset)'"
  df           = "!git flags; git diff $FLAG_DIFF"
  dfc          = "!git flags; git diff $FLAG_DIFF --cached"