里面的awk期望

Question

I'm having errors when sending this to expect

send "someagent_id=`ps aux | grep someagent| grep -v grep | awk '{print $2}'`\r"

Error:

can't read "2": no such variable
    while executing
"send "someagent_id=`ps aux | grep someagent| grep -v grep | awk '{print $2}'`\r""

Answer 1

If all you want is the PID for some process, you don't need all this messy thing: ps aux | grep someagent| grep -v grep | awk '{print $2}' ps aux | grep someagent| grep -v grep | awk '{print $2}' ps aux | grep someagent| grep -v grep | awk '{print $2}' .

You can get a process PID just with pgrep :

In your case it would be:

send "someagent_id=$(pgrep SOMEAGENT)\r" 

Answer 2

try this :

   someagent_id=$(ps aux | grep someagent| grep -v grep | awk '{print $2}'\r)
   send $someagent_id

`` --> previous version $ --> new version. Both do the same thing

Answer 3

try this

send "someagent_id=`ps aux | grep someagent| grep -v grep | awk '{print \$2}'`\r"

and maybe better with this 1 pipe only version

send "someagent_id=`ps aux | awk '/someagent/ && ! /awk/ {print \$2}'`\r"

Answer 4

With ps options

 ps -C someagent -o pid=

 send "someagent_id=$(ps -C someagent -o pid=)"