ruby-on-rails - Ruby 抑制系统真实输出

Question

我正在运行后台 rake 任务。（使用 '＆'）。问题是我希望它有时停止。所以我写了这个：

pinger_pid = system "ps | grep rake | awk '{print $1}'"
puts pinger_pid
system "kill -9 #{pinger_pid}"

似乎我得到了一个“真正的”输出垃圾！我怎样才能删除它？

输出：

ERROR: garbage process ID "true".
Usage:
  kill pid ...              Send SIGTERM to every process listed.
  kill signal pid ...       Send a signal to every process listed.
  kill -s signal pid ...    Send a signal to every process listed.
  kill -l                   List all signal names.
  kill -L                   List all signal names in a nice table.
  kill -l signal            Convert between signal numbers and names.

Answer 1

系统返回真或假，取决于命令的成功与否。

使用 %x 捕获输出：

pinger_pid = %x(ps | grep rake | awk '{print $1}')
puts pinger_pid
system 'kill', '-9', pinger_pid