I am using wget to grab some files from one of our servers once an hour if they have been updated. I would like the script to e-mail an employee when wget downloads the updated file.
When wget does not retrieve the file, the last bit of text wget outputs is
file.exe' -- not retrieving.
<blank line>
How do I watch for that bit of text and only run my mail command if it does not see that text?
I would do it with something like
if ! wget ... 2>&1 | grep -q "not retrieving"; then
# run mail command
fi
wget outputs that "not retrieving" to stderr, not stdout. I edited it to redirect stderr to stdout, so now it should work.What is the exit status of 'wget' when it succeeds, and when it fails? Most likely, it reports the failure with a non-zero exit status, in which case it is largely trivial:
if wget http://example.com/remote/file ...
then mailx -s "File arrived at $(date)" [email protected] < /dev/null
else mailx -s "File did not arrive at $(date)" [email protected] < /dev/null
fi
If you must analyze the output from 'wget' then you capture it and analyze it:
wget http://example.com/remote/file ... >wget.log 2>&1
x=$(tail -2 wget.log | sed 's/.*file.exe/file.exe/')
if [ "$x" = "file.exe' -- not retrieving." ]
then mailx -s "File did not arrive at $(date)" [email protected] < /dev/null
else mailx -s "File arrived at $(date)" [email protected] < /dev/null
fi
However, I worry in this case that there can be other errors that cause other messages which in turn lead to inaccurate mailing.
if ${WGET_COMMAND_AND_ARGUMENTS} | tail -n 2 | grep -q "not retrieving." ; then
echo "damn!" | mail -s "bad thing happened" [email protected]
fi
${} (I think you meant $() which wouldn't work anyway since it would try to execute the results of the wget).
$()? Yes, of course I meant ${}, indeed {} is safe to omit, but it doesn't hurt either.