ref: c4e30bede2f79c42dacb8c91713abf4a4d91c45c
dir: /sys/src/libc/port/lnrand.c/
#include <u.h> #include <libc.h> #define MASK 0x7fffffffL long lnrand(long n) { long slop, v; if(n < 0) return n; slop = MASK % n; do v = lrand(); while(v <= slop); return v % n; }