MoveIfChange   [plain text]

# Rename a file only if it is different from a previously existing
# file of the same name.  This is useful for keeping make from doing
# too much work if the contents of a file haven't changed.

# This is an MPW translation of the standard GNU sh script move-if-change.

Set exit 0

If "`exists -f "{2}"`"
  Compare "{1}" "{2}" >dev:null
  If {status} != 0
    Rename -y "{1}" "{2}"
  Else
    Echo "{2}" is unchanged
    Delete -i -y "{1}"
  End
Else
  Rename -y "{1}" "{2}"
End