NET::FTP put()/append() error handling

Viki@Stag has asked for the wisdom of the Perl Monks concerning the following question:

Hi monks, I need help on this. I have read the documentation of Net::FTP, it says for put() " NOTE: If for some reason the transfer does not complete and an error is returned then the contents that had been transferred will not be remove automatically. " What is the error returned? And how can I check it in the code? I currently call put() in a loop with retries, here is a part of the code:

my $ftp_obj = get_ftp_obj();
my $put_try = 0;
my $cflag = 0;
my $MAX_RETRIES = 5;
while ($put_try < $MAX_RETRIES) {
        my $ret;
    $ret = $ftp_obj->put("$file_name") if ($put_try == 0);
    $ret = $ftp_obj->append("$file_name") if ($put_try > 0);
    last if (!$ret);  # is this correct????
    $put_try++;
    print "Retrying to append $file_name, $put_try\n";
    if ($put_try == $MAX_RETRIES) {
         die "Not able to copy $file_name\n";
    }
}
[download]

Am i checking the return value of the put()/append() properly?
Thanks in advance

Comment on NET::FTP put()/append() error handling Download Code

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Re: NET::FTP put()/append() error handling by pc88mxer (Vicar) on Jul 02, 2008 at 05:24 UTC
For starters, declaring `my $ret` twice in the same scope isn't going to work as expected. Consider this: `sub myohmy { my $y = shift; my $x = "true" if ($y); my $x = "not true" if (!$y); return $x; } print "myohmy(0) = ", myohmy(0), "\n"; print "myohmy(1) = ", myohmy(1), "\n"; __END__ # outputs: myohmy(0) = not true myohmy(1) =` [download] `use warnings` will catch this problem. To fix it you'll need to re-write it as: `my $ret; $ret = ... if ($put_try == 0); $ret = ... if ($put_try > 0);` [download] but I'd probably just use an `if...else...` construct. Another issue with your retry logic is that if you want to recover from a failed `put` by appending data, you need to: figure out how much data was transfered by the `put` operation. open the source file and seek to that location perform an `append` operation using the opened file handle (as opposed to the source file's name) It might be easier just to re-`put` the file (depending on its size.)	[reply] [d/l] [select]
Re^2: NET::FTP put()/append() error handling by Viki@Stag (Sexton) on Jul 02, 2008 at 07:00 UTC
Thanks for the logic... ++	[reply]
Re^2: NET::FTP put()/append() error handling by Viki@Stag (Sexton) on Jul 02, 2008 at 07:06 UTC
since this file is a binary file, should i use binmode(FILEHANDLE)?	[reply]
Re^3: NET::FTP put()/append() error handling by pc88mxer (Vicar) on Jul 02, 2008 at 13:43 UTC
It wouldn't hurt, especially if you are on a Windows system. `Net::FTP` uses `read()` to read from the local file during a `put`.	[reply] [d/l] [select]
Re^4: NET::FTP put()/append() error handling by Viki@Stag (Sexton) on Jul 07, 2008 at 06:31 UTC
Re: NET::FTP put()/append() error handling by Mr. Muskrat (Canon) on Jul 02, 2008 at 18:18 UTC
What is the error returned? And how can I check it in the code? Use `$ftp->message` to get the error. See the Net::FTP synopsis for an example.	[reply] [d/l]