cron and shell env variables

lt_wentoncha · 07-13-2005, 08:36 PM

Hi all,

I have this scrip that I wanted cron to run hourly, it's a script that wgets to zoneedit dns servers to update my dynamic IP addy on their dns servers. So I put in the script:

echo wget -o ..
wait
exit

It echoes the command to shell but I don't think it exectutes this, as if it's just echoing the command rather than executing it whenever I do ./script in the shell in the current directory of the script.

I already setup the following in crontab:

59 * * * * * * some_user run-parts /"directory of script"

and it confirms my suspicisons that the script isn't right. How do I go about setting up the script so that it runs the commands in it? Better yet, how do I setup crontab to exec the script only when my IP address from my ISP changes?

Also, hwo do I go about permanently changing environment variables for X Terminal, Konsole, and bash shells?

Many, many thanks.

crabboy · 07-13-2005, 09:53 PM

When setting up cron jobs always assume that cron starts you script in never-never land. You should put full paths in front of all your executables and done use .. as a directory unless you cd there first.

Code:

cd <some dir>
echo /usr/bin/wget ..
wait
exit

Cron can't be setup to run a script when your IP changes. It's not his job to do so. It only executes based on time.

Permanently set env variabels by either putting them in /etc/profile (system wide) or add them to /home/user/.profile or /home/user/.bashrc (.bashrc if you use the bash shell)

lt_wentoncha · 07-13-2005, 11:11 PM

Quote:

Originally posted by crabboy
When setting up cron jobs always assume that cron starts you script in never-never land. You should put full paths in front of all your executables and done use .. as a directory unless you cd there first.

Code:

cd <some dir> echo /usr/bin/wget .. wait exit

Cron can't be setup to run a script when your IP changes. It's not his job to do so. It only executes based on time.

Permanently set env variabels by either putting them in /etc/profile (system wide) or add them to /home/user/.profile or /home/user/.bashrc (.bashrc if you use the bash shell)

Hmmmmm, adding in the cd (cd / or echo cd /) didn't work.

Code:

(change directory)
echo wget -O - --http-user=username --http-passwd=password 'http://dynamic.zoneedit.com/auth/dynamic.html?host=www.mydomain.com' 
wait
exit

Normally, if I just run the command in shell, some processing would be done and something like this gets output to shell:

Code:

--21:48:23-- »https://dynamic.zoneedit.com/auth/dynamic.html..
=> `-'
Resolving dynamic.zoneedit.com... 69.72.142.98
Connecting to dynamic.zoneedit.com[69.72.142.98]:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 101 [text/html]

0% [ ] 0 --.--K/s 
100%[====================================>] 101 --.--K/s

21:48:23 (320.24 KB/s) - `-' saved [101/101]

But if I do ./"script" it just echoes

Code:

wget -O - --http-user=username --http-passwd=password 'http://dynamic.zoneedit.com/auth/dynamic.html?host=www.mydomain.com'

Any other suggestions? Thanks you very much for replying.

crabboy · 07-14-2005, 01:39 PM

The script you posted only has a 'echo wget ' so the output of:

wget -O - --http-user=username --http-passwd=password 'http://dynamic.zoneedit.com/auth/dynamic.html?host=www.mydomain.com'

would be correct. What results do you get without the echo in front of wget?

lt_wentoncha · 07-16-2005, 01:15 PM

Sorry, my DSL was down but now it's back up.

Anyways, when I echo that command, I don't get the ouput I should get. It seems to just litterally write that command in console and not execute it. Any thoughts?

Thanks again.

mhallbiai · 07-16-2005, 01:20 PM

crabboy is correct, echo is doing what it is designed to do 'echo' the string to stdout (unless otherwise specified).

so echo wget with options will return wget with options to stdout.
if you are actually wanting to run wget with option then you won't need to use echo before it in your script.

hope this helps