Plan 9 from Bell Labs’s /usr/web/sources/plan9/sys/src/libc/port/nrand.c
#include <u.h> #include <libc.h> #define MASK 0x7fffffffL int nrand(int n) { long slop, v; if(n < 0) return n; if(n == 1) return 0; /* and if n == 0, you deserve what you get */ slop = MASK % n; do v = lrand(); while(v <= slop); return v % n; }