解决方法
像这样写一个包装脚本start-stopped.sh：
- #!/bin/sh
- kill -STOP $$ # suspend myself
- # ... until I receive SIGCONT
- exec $@ # exec argument list
然后称之为：
- sudo -u $SOME_USER start-stopped.sh mycommand & # start mycommand in stopped state
- MYCOMMAND_PID=$!
- setup_iptables $MYCOMMAND_PID # use its PID to setup iptables
- sudo -u $SOME_USER kill -CONT $MYCOMMAND_PID # make mycommand continue
- wait $MYCOMMAND_PID # wait for its termination
- MYCOMMAND_EXIT_STATUS=$?
- teardown_iptables # remove iptables rules
- report $MYCOMMAND_EXIT_STATUS # report errors,if necessary
然而,这一切都是矫枉过正的.您不需要在挂起状态下生成进程以完成工作.只需创建一个包装器脚本setup_iptables_and_start：
- #!/bin/sh
- setup_iptables $$ # use my own PID to setup iptables
- exec sudo -u $SOME_USER $@ # exec'ed command will have same PID
然后称之为
- setup_iptables_and_start mycommand || report errors
- teardown_iptables
