Re: sftp status error/status code

In the last episode (Apr 12), alan.cline@sas.com said:
> Is there a way to receive "sftp status codes" as part of the sftp
> command response message on stdout, when an sftp command is issued on
> stdin.
>
> For instance: Issuing the "get" command interactively to an ftp
> server, I receive the following response on stdout:
>
> 550 filename: No such file or directory.
>
> The same command sent to an OpenSSH sftp server receives the
> following response:
>
> Couldn't stat remote file: No such file or directory. File "/local/abbb/foo" 
> not found.
>
> I need to programmatically extract the status code off the stdout
> output.  However, I haven't found a way to get the "status code" in
> stdout.
>
> Does anyone know of a way to get the "sftp status codes" sent to
> stdout, like ftp servers do?

The answer is that there is no FTP-like status code.  The SFTP protocol
is more like NFS, SMB or other network filesystem protocols.  You stat
a filename to see if it's a directory, if it's not, you open it and get
a filehandle back, then you read small chunks of the file in a loop
until a read returns EOF.  What's happening to you is the stat is
failing, and sftp is printing "Couldn't stat remote file: %s", where %s
is the error string passed by the server in its error packet.

http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-9.1

If you want to transfer files from within a program, check out curl's
library API.  Versions 7.16.1 and newer support the sftp and scp
protocols.

-- 
        Dan Nelson
        dnelson@allantgroup.com