linux：启动时挂起进程

#!/bin/sh
kill -STOP $$                                    # suspend myself 
                                                 # ... until I receive SIGCONT
exec $@                                          # exec argument list

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

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

setup_iptables_and_start mycommand || report errors
teardown_iptables

fork

exec

system

#!/bin/bash

echo \"Pid is $$\"
echo -n \"Press Enter..\" 
read 
exec $@

/bin/bash ./run.sh <your command>

gdb

main

suspend

PID

SIGCONT

exec