LinuxQuestions.org - [SOLVED] bash script syntax fail as root

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bash script syntax fail as root

Hello,
I'm scratching my head over a very simple netcat-based heartbeat monitoring script i wrote.

here we go:

Code:

echo `date --utc "+%Y-%m-%d %H:%M:%SZ"` script started

HOST=$1

SLEEP_TIME=1

LAST_STATE=12345

while [[ 0 == 0 ]]

        do

        heartbeat $HOST

        NEW_STATE=$?

        if [[ $LAST_STATE != $NEW_STATE ]]

                then

                LAST_STATE=$NEW_STATE

                if [[ $NEW_STATE == 0 ]]

                        then

                        echo `date --utc "+%Y-%m-%d %H:%M:%SZ"` Host $HOST up

                else

                        echo `date --utc "+%Y-%m-%d %H:%M:%SZ"` Host $HOST down

                fi

        fi

        sleep $SLEEP_TIME

done

"heartbeat" is just a simple netcat one liner that checks for the "connection established"/ACK.
Now, if i run this script as my user, i get the expected result. However, running it with sudo, out comes:

Code:

2011-04-12 17:13:36Z script started

/usr/local/bin/heartbeat_monitor: 20: [[: not found

I'm completely lost on this one :confused:

It could be that sudo runs the script using a different shell. You could try putting a "shebang" line at the top of the script to ensure it is always run using the nominated shell:

Code:

#! /bin/bash

the root shell is bash, but thanks, i sometimes forget the shebang

The script runs fine when in a root shell, but fails with sudo.
Also, I've added "heartbeat_monitor localhost &" to my rc.local, and "sudo /etc/rc.local" fails with the same error

Code:

goncalopp@kirjava:~$ cat /etc/rc.local

#!/bin/sh -e

/usr/local/bin/heartbeat_monitor cb.goncalopp.com >> /var/log/heartbeat.log &

nc -k -l 23576 &

exit 0

goncalopp@kirjava:~$ heartbeat_monitor localhost

2011-04-12 18:58:21Z script started

2011-04-12 18:58:22Z Host localhost down

^Cgoncalopp@kirjava:~$ sudo heartbeat_monitor localhost

2011-04-12 18:58:33Z script started

/usr/local/bin/heartbeat_monitor: 20: [[: not found

goncalopp@kirjava:~$ sudo su

kirjava:/home/goncalopp# heartbeat_monitor localhost

2011-04-12 18:58:44Z script started

2011-04-12 18:58:44Z Host localhost down

^Ckirjava:/home/goncalopp# sudo heartbeat_monitor localhost

2011-04-12 18:58:47Z script started

/usr/local/bin/heartbeat_monitor: 20: [[: not found

seriously... I'm feeling like a total noob

--edit--
oh, i've put heartbeat and heartbeat_monitor on /usr/local/bin/, if that makes any difference... I'd think not

Did you add a shebang as catkin suggested?

Code:

goncalopp@kirjava:~$ sudo echo $SHELL

/bin/bash

I did that and immediately continued trying other things. My mistake, apparently.

Somehow, sudo manages to ignore both the shell defined in the passwd and the $SHELL environment variable, and was executing the script with dash... No idea why :confused:
But, yeah, that'll remember me to put shebangs everywhere...
Thanks for the help of both

Quote:

Originally Posted by goncalopp (Post 4322491)

Somehow, sudo manages to ignore both the shell defined in the passwd and the $SHELL environment variable, and was executing the script with dash... No idea why :confused:

Confirming: this happens both using sudo script_name and sudo su followed by entering the script name at the command line? In all cases with no options to either sudo or su?

Which distro?

"sudo su" works, "sudo" doesn't.

Tested on Ubuntu (10.10, 9.04) and Debian squeeze.
Reading the sudo manual, there's an "-i" argument that simulates a login; that seems to work, but then you need to specify absolute paths for the command. "-s" to specify a shell also works.
"sudo echo $SHELL" being /bin/bash still baffles me, though.