any way to make a disable-arrowhead-line?

[zeerd]

for example, a line with a X, with means this line is disabled.

such like :

-----X

[schplurtz]

Hi.
That's a really good idea. However, I don't have the skill to modify the parser that comes from https://github.com/dhobsd/asciitosvg.

As a workaround, perhaps you can use some unicode char in the symbol category. This won't be perfect however. The biggest problem is different platform may render the char differently. See https://www.key-shortcut.com/en/writing-systems/35-symbols/symbols-typography for example.