NAME

       sfddiff - compare two font files

SYNOPSIS

       sfddiff   [--help]   [--ignorehints]   [--ignorenames]  [--ignoregpos]  [--ignoregsub]  [--ignorebitmaps]
       [--exact] [--warn] [--merge outfile] [--usage] [--version] fontfile1 fontfile2

DESCRIPTION

       The program sfddiff compares two font files, which may be in any format that fontforge(1) can  read.   It
       will notice the following differences:

       1)  Characters are present in one font but not in the other.

       2)  Characters  are present in both fonts but have different sets of outlines or references. The outlines
           may be compared so that only exact matches are  accepted,  or  so  that  a  fuzzier  match  is  used.
           Similarly  references  may  need  to  match  exactly,  or may be matched after an unlink.  This fuzzy
           comparison is useful when comparing truetype and postscript fonts, or  when  comparing  a  font  with
           references to one without.

       3)  The PostScript hints or TrueType instructions are different.

       4)  The font names (the TrueType 'name' tables) differ.

       5)  The kerning (and other 'gpos' information) differs.

       6)  The ligatures (and other 'gsub' information) differ.

       7)  Any bitmap strikes present in one font but not in the other.

       8)  Any  bitmap  characters  present  in  one  strike of one font but not in the equivalent strike of the
           other.

       9)  Any bitmap characters which differ.

OPTIONS

       --help          Provide a description with a list of the available options.

       --ignorehints   Suppress the reporting of hint/instruction differences.

       --ignoregpos    Suppress the reporting of kerning (and other 'gpos') differences.

       --ignoregsub    Suppress the reporting of ligature (and other 'gsub') differences.

       --ignorenames   Suppress the reporting of name string differences.

       --ignorebitmaps Suppress the reporting of bitmap differences.

       --exact         Require outlines to match exactly.

       --warn          Warn if the outlines/references are slightly different.

       --merge outfile Store a merged version of the two fonts into the specified output file.  The merged  data
                       will be based on sfdfile1, any characters present in sfdfile2 but not in sfdfile1 will be
                       added,  and  the outlines of sfdfile2 will be placed in the background.  Finally, for any
                       characters with different outlines or references the background  of  the  character  will
                       contain  the  outlines from sfdfile2 (references will be unlinked into outlines and those
                       outlines also will be added).

       --usage         Display the usage description.

       --version       Display the current version.

SEE ALSO

       fontforge(1)

       The HTML version of the FontForge manual, available online at: http://fontforge.sourceforge.net/.

NOTE

       FontForge used to be called PfaEdit.

AUTHORS

       FontForge is Copyright © 2000–2014 by George Williams, and  is  currently  maintained  by  the  FontForge
       development team.  See /usr/share/doc/fontforge/AUTHORS for a comprehensive list of contributors.

LICENSE

       The    sfddiff    program    is    licensed    under    GPLv3+:    GNU    GPL    version 3    or    later
       (http://gnu.org/licenses/gpl.html)    with    many     parts     covered     by     a     BSD     license
       (http://fontforge.org/license.html).  Please read the LICENSE file included in the FontForge distribution
       for details, or see https://github.com/fontforge/fontforge/blob/master/LICENSE.

       FontForge  is available as a whole under the terms of the GNU GPL (http://www.gnu.org/copyleft/gpl.html),
       version 3 or any later version.  However, almost all of its parts are available under  the  "revised  BSD
       license"  (http://www.law.yi.org/~sfllaw/talks/bsd.pdf)  because  FontForge  was mostly written by George
       Williams, using that license.

       The Revised BSD License is very permissive, and allows for code to be  combined  with  other  code  under
       other licenses.

       There  are many useful libraries available under copyleft libre licenses, such as the LGPL and GPL, which
       FontForge started to use in 2012.

       For example, Pango and Cairo are available under the LGPL.

       Some features added since 2012 are licensed by their individual developers under the GPLv3.

BUGS

       See the FontForge Github Issue Tracker, at https://github.com/fontforge/fontforge/issues/.

                                                   2017 Jun 18                                        SFDDIFF(1)