Question

I have a script that updates a server with some stats once per day. The script works as intended when running from command line, but when running from cron some of the variables are not passed to curl.

Here is an example of the code:

#!/bin/sh
PATH=/bin:/sbin:/usr/bin:/usr/sbin
/bin/sh /etc/profile

MACADDR=$(ifconfig en0 | grep ether | awk '{print $2}')
DISKUSED=$(df / | awk '{print $3}' | tail -n1)
DISKSIZE=$(df / | awk '{print $2}' | tail -n1)

# HTTP GET PARAMS
GET_DELIM="&"
GET_MAC="macaddr"
GET_DS="disk_size"
GET_DU="disk_used"

# Put together the query
QUERY1=$GET_MAC=$MACADDR$GET_DELIM$GET_DS=$DISKSIZE$GET_DELIM$GET_DU=$DISK_USED

curl http://192.168.100.150/status.php?$QUERY1

The result in the cron job is http://192.168.100.150/status.php?macaddr=&disk_size=&disk_used=

I am not sure if it is some problem with the variables, or possibly with awk trying to parse data with no terminal size specified, etc.

Any help is appreciated.

Answer 1

When you’re running into problems like this it’s almost always an environment issue.

Dump the results of “env” to a file and inspect that. You can also run your script with top line of

#!/bin/sh -x

to see what’s happening to all the variables. You might want to use a wrapper script so you can redirect the output this provides for analysis.