Re: question on non interactive execution

[Gearoid Murphy <gearoid.murphy@xxxxxx>]

If you could post a small, self-contained example which demonstrates 
this issue, it would help immensely in diagnosing the problem.

On 29/02/12 06:43, Snoke, Nancy Meares 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.
>
> Can anyone offer any advice on what to change so that I can get this 
> function to work appropriately on multiple calls? On secondary calls, 
> ssh_channel_request_exec(channel, cmd) does not return SSH_OK.
>
> Any help would be appreciated.
>
> Nan