impact printer

[maxy04]

Good morning, i'm a newbie of the forum.
My name is Massimo and i'm from Italy (don't ask me about pizza, wine and maccheroni, please! ).

i'm developing a java program, on slack.
it must print on a impact printer, only text (raw text, no fonts, sizes, and so on), like old-style printing (for examples as400 printing of banks account), on parallel port.

i don't want to use directly /dev/lp0, and i'm not a fan of cups.
what is the right way to do it?

the /dev/lp0 is buffered, or if i send too many characters the printer buffer can be overflowed?


the program is a statistic-datacruncher, so it prints while the main cycle is running, not at the end of the program, so i can't generate a file and print it

can i interface the program directly to lpr?
i need to print one line at a time, not a page, so the system choosen must not send form feed.