First of all, you can just use Persian Fonts instead :-).

As described Persian Script is an adaption of arabic script.

To search for fonts which could match you can use:

$ otfinfo -s FreeFarsi.ttf arab Arabic 

or for all fonts:

$ otfinfo -s *.ttf *.otf FreeFarsi-BoldItalic.ttf:DFLT Default FreeFarsi-BoldItalic.ttf:arab Arabic FreeFarsi-Bold.ttf:DFLT Default FreeFarsi-Bold.ttf:arab Arabic FreeFarsi-Italic.ttf:DFLT Default FreeFarsi-Italic.ttf:arab Arabic FreeFarsi-Mono.ttf:arab Arabic FreeFarsi.ttf:arab Arabic homa.ttf:arab Arabic nazlib.ttf:arab Arabic nazli.ttf:arab Arabic titr.ttf:arab Arabic 

As you can see the scripts are not always called arab but 'DFLT'. A fallback solution is the ansfer of @terdon.

First of all, you can just use Persian Fonts instead :-).

As described Persian Script is an adaption of arabic script.

To search for fonts which could match you can use:

$ otfinfo -s FreeFarsi.ttf arab Arabic 

or for all fonts:

$ otfinfo -s *.ttf *.otf FreeFarsi-BoldItalic.ttf:DFLT Default FreeFarsi-BoldItalic.ttf:arab Arabic FreeFarsi-Bold.ttf:DFLT Default FreeFarsi-Bold.ttf:arab Arabic FreeFarsi-Italic.ttf:DFLT Default FreeFarsi-Italic.ttf:arab Arabic FreeFarsi-Mono.ttf:arab Arabic FreeFarsi.ttf:arab Arabic homa.ttf:arab Arabic nazlib.ttf:arab Arabic nazli.ttf:arab Arabic titr.ttf:arab Arabic 

As you can see the scripts are not always called arab but 'DFLT'. A fallback solution is the answer of @terdon.