Plan 9 from Bell Labs’s /usr/web/sources/plan9/sys/src/cmd/unix/drawterm/libauthsrv/nvcsum.c
#include <u.h> #include <libc.h> #include <auth.h> uchar nvcsum(void *vmem, int n) { uchar *mem, sum; int i; sum = 9; mem = vmem; for(i = 0; i < n; i++) sum += mem[i]; return sum; }