SFDDIFF(1)

💖 SFDDIFF 💖

okay bestie, so this is sfddiff from the General Commands Manual section — it's a whole little program that looks at two font files and tells you every single way they're different. it's giving detective energy fr fr 🔍✨

✨ NAME ✨

sfddiff — compare two font files 🫶

🌸 SYNOPSIS 🌸

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

💅 DESCRIPTION 💅

so sfddiff compares two font files — and lowkey it doesn't even care what format they're in, as long as fontforge(1) can read them. iconic. it will clock the following differences:

1. characters are in one font but not in the other 💀
2. characters are in both fonts but they have different sets of outlines or references. and ok so the outlines can be compared so that only exact matches count, or so a fuzzier match is used. same deal with references — they might need to match exactly, or they might get matched after an unlink. this fuzzy comparison is super useful when you're comparing truetype and postscript fonts, or when you're comparing a font with references to one without. iykyk ✨
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) differs
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

like?? it catches everything. main character behavior honestly 👑

🎀 OPTIONS 🎀

• --help — drops a description plus the whole list of available options. slay.
• --ignorehints — shhh, 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, no wiggle room, periodt 💅
• --warn — warn you if the outlines/references are only slightly different. a lil heads up, bestie 🫶
• --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). it's a whole collab 🌈
• --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. glow-up era fr fr 💜

👑 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. we love a whole team effort 🫶✨

🌸 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. very generous of it 💖

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/. (if you found something cursed, tell them, they'll handle it 🫶)

and that's the whole page bestie!! this one's from the 2017 Jun 18 release of the General Commands Manual — sfddiff(1), source and date and all. go compare some fonts, you absolute icon 💅✨🎀