Alex Chen Alex Chen - 14 days ago 7
Linux Question

Getting sudo and nohup to work together

Linux newbie here.

I have a perl script which takes two command line inputs. I tried to run it in the background but this is what I got:

[~user]$ nohup sudo ./ascii_loader_script.pl 20070502 ctm_20070502.csv &
[2] 19603
[~user]$ nohup: appending output to `nohup.out'


after the system returns "nohup: appending output to `nohup.out'", no new prompt will appear. Then as long as I type in some other command, the shell will tell me that the process is stopped:

[~user]$ nohup sudo ./ascii_loader_script.pl 20070502 ctm_20070502.csv &
[2] 19603
[~user]$ nohup: appending output to `nohup.out'
ls
ascii_loader_script.pl format_wrds_trd.txt nohup.out norm_wrds_trd.cfg
[2]+ Stopped nohup sudo ./ascii_loader_script.pl 20070502 ctm_20070502.csv


I've looked at this post and tried to do "sudo date" before executing the command. Still got the same thing.
http://www.sudo.ws/pipermail/sudo-users/2003-July/001648.html

Answer

The problem here, imho, is not nohup, but background processing sudo.

You are putting the process in background (& at end of command) but probably sudo needs password authentication, and that is why the process stops.

Try one of these:

1) remove the ampersand from end of command, reply to passord prompt and afterwords put it in background (by typing CTRL-Z - which stops the process and issuing the bg command to send it to background)

2) Change the /etc/sudoers to not ask for users password by including the line: myusername ALL=(ALL) NOPASSWD: ALL

If besides the password reply your application waits for other input, then you can pipe the input to the command like this: $ cat responses.txt|sudo mycommand.php

hth

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