sfddiff [-merge outfile] [-ignorehints] [-version] [-help] sfdfile1
Sfddiff compares (or merges) two of pfaedit's sfd files and checks for differences.
It will notice:
-merge flag is specified the following argument should
be the name of an output file into which sfddiff will store a merged version
of the two fonts. This will contain everything from sfdfile1 as well as any
characters present in sfdfile2 but not in sfdfile1. For any characters with
different outlines or references, the background of the the character will
contain the splines from sfdfile2 (sadly references can not be placed in
-ignorehints flag is specified, then no hint differences
will be reported.
-help will provide a mini description and will list the available
-usage will list the available options.
-version will display the current version of sfddiff
(a six digit string containing the date stamp of the source files).
Doesn't work on CID keyed fonts yet.