Re: question on non interactive execution

[Andreas Schneider <asn@xxxxxxxxxxxxxx>]

On Wednesday 29 February 2012 06:43:36 you wrote:
> So I wrote a function that takes a channel, command and filename and runs a
> ssh_channel_remote_exec on the channel with the command, and dumps the
> output in the given file.
> 
> int ssh_library_remote_cmd_to_file(ssh_channel channel, const char *cmd,
>                                                    const char *filename)
> {
>     char buffer[256];
>     int nbytes;
>     int rc;
> 
>     if (!filename || !cmd || !ssh_channel_is_open(channel))
>         return SSH_ERROR;
> 
>     rc = ssh_channel_request_exec(channel, cmd);
>     if (rc == SSH_OK) {
>         FILE *fp = fopen(filename, "w");
> 
>         if (!fp)
>             return SSH_ERROR;
> 
>         nbytes = ssh_channel_read(channel, buffer, sizeof(buffer), 0);
> 
>         while (nbytes > 0 && ssh_channel_is_open(channel) &&
>                nbytes != SSH_ERROR && !ssh_channel_is_eof(channel))
>         {
>             write(1, buffer, nbytes);
>             fwrite(buffer, sizeof(buffer[0]),
> sizeof(buffer)/sizeof(buffer[0]),$ nbytes = ssh_channel_read(channel,
> buffer, sizeof(buffer), 0); }
>         fclose(fp);
>         if (nbytes < 0)
>             return SSH_ERROR;
>     }
>     return SSH_OK;
> }
> 
> 
> It works fine the first time it is called, but does not work when called a
> second time.  I have tried using the same channel, using different channels
> that are part of the same session, and using different channels on
> different sessions.   The last instance really surprises me.

After you have successfully executed the command you have to close the 
channel. See our tutorial at:

http://api.libssh.org/stable/libssh_tutor_command.html

Cheers,

	-- andreas

-- 
Andreas Schneider                   GPG-ID: F33E3FC6
www.cryptomilk.org                asn@xxxxxxxxxxxxxx