ref: d44a890382840275a3772ae4a3b2ec2c0440a71f
dir: /sys/src/cmd/postscript/p9bitpost/pslib.h/
char *psinit(int, int); /* second arg is debug flag; returns "" on success */ int image2psfile(int, Memimage*, int); void psopt(char *, void *); int paperlength; int paperwidth;