[bash] Remote file existence check

danket · 01-14-2008, 12:55 PM

Hi!
Would anyone have an idea how (using bash script) to check if remote file exists? I'd need to know if file ftp://user:pass@server.com/dir/somefile.txt has already been created, if so, wget would down it. I just need a command which would return 'true' or 'false'.
I have experimented with test and wget, but it's a wrong path, I guess. I'm getting kinda confused :/
Thanks in advance,
Dan

bigrigdriver · 01-14-2008, 01:28 PM

Maybe something like

Code:

if [ -e ftp://user:pass@server.com/dir/somefile.txt ]; then
     wget ftp://user:pass@server.com/dir/somefile.txt
fi

danket · 01-14-2008, 01:36 PM

Quote:

Originally Posted by bigrigdriver

Maybe something like

Code:

if [ -e ftp://user:pass@server.com/dir/somefile.txt ]; then
     wget ftp://user:pass@server.com/dir/somefile.txt
fi

Thanks for the tip, but 'test -e' works only on local file system, I'd have remote fs mounted locally, which is immposible as of today.

anomie · 01-14-2008, 02:49 PM

What's wrong with just attempting to wget it? If it's not there, wget errors out...

To test for the presence of the file you'd have to authenticate anyway (based on what you've shown here).

danket · 01-14-2008, 03:32 PM

There's nothing wrong with wget :) But thanks anyway, you put me on right track :)

colucix · 01-14-2008, 05:39 PM

You may also consider the following options to wget:

Quote:

--tries=number
Set number of retries to number. Specify 0 or inf for infinite retrying.
The default is to retry 20 times, with the exception of fatal errors like
"connection refused" or "not found" (404), which are not retried.

--waitretry=seconds
If you don’t want Wget to wait between every retrieval, but only between
retries of failed downloads, you can use this option. Note that this option
is turned on by default in the global wgetrc file.