Yes implementation in Nim

yes.nim

import os

# Handle Ctrl-C signal
setControlCHook(proc() {.noconv.} = quit 0)

# Use POSIX write
proc write(fd: cint, buffer: pointer, count: cint) {.header: "<unistd.h>", importc: "write".}

const pageSize = 4096
var yes: string
var buffer = ""
var bufferLen: cint

# Use argument or y
if os.paramCount() > 0:
  yes = os.paramStr(1) & '\10'
else:
  yes = "y\n"

  # Fill up the buffer
for i in 2..yes.len:
  if i*pageSize mod yes.len == 0:
    bufferLen = cint(i*pageSize)
    break

while buffer.len < bufferLen:
  buffer.add(yes)

# Main yes loop
let buffPtr = cast[pointer](addr buffer[0])
while true:
  write(1, buffPtr, bufferLen)