There is nothing more difficult than making a custom cover sheet for Hylafax. Of all the programming languages I have ever glanced at, Postscript is by far the most cryptic. I spent about 6 hours the other day trying to follow the instructions on the official Hylafax tweaking page. . I designed my cover sheet in photoshop and left the fields blank. Exported it as PNG and imported it into TGIF. I used TGIF's text tool and printed as EPS at first and tried using the script to make a coversheet.
That just didn't work.
I followed the instructions on this page for manual preparation of the raw PS file for faxcover.
I spent 5 hours banging my head against the wall trying to figure out why when I replaced
and added the macros to the top of my PS file , nothing was working right (Fields were not replaced)
After many hours I had slipped up and accidentally left some fields in the format seen in the PS file (the format the fields were in the raw PS printoff from TGIF)
Now why would that work? Apparently, All I needed to do was just place the fields with TGIF in that format and things would work. So I did that, tried again and everything worked perfectly. Now just to make that sheet the default cover sheet system wide as opposed to AvantFax's cover sheet. I copied the faxcover.ps file to /etc/hylafax and /var/spool/hylafax/etc and made sure their timestamps were synced (hylafax won't start otherwise).
I left the -C argument out of the sendfax command to use the system template and voila! Failure!. The resulting fax still had AvantFax's coversheet. I remembered that during installation there was a note about replacing hylafax's default coversheet. I looked into the AvantFax installer source code
(debian-install.sh from AvantFax 3.1.2)
mv $HYLADIR/bin/faxcover $HYLADIR/bin/faxcover.old
ln -s $INSTDIR/includes/faxcover.php $HYLADIR/bin/faxcover
Shocked! AvantFax actually replaces the system wide faxcover program with a CLI PHP script! Their PHP script is made to mimic faxcover (but they conveniently forgot to update the man page for faxcover). I looked into the code, and its set to use AvantFax's cover sheet in the avantfax installation directory ($INSTDIR/includes/faxcover.ps). I replaced that file and Voila, My custom coversheet was working!