Re: redirecting output to a file with g_spawn_async

[Chris Vine <chris cvine freeserve co uk>]

On Thursday 06 October 2005 19:16, Colossus wrote:

> thanks for replying. I don not read with the Unix "read" function but
> with G_IO_Channel glib functions:
>
> static gboolean ExtractToDifferentLocation (GIOChannel *ioc,
> GIOCondition cond, gpointer data)
> {
>       if (cond & (G_IO_IN | G_IO_PRI) )
>       {
>               //while (gtk_events_pending() )
>                       //gtk_main_iteration();
>               gchar *line = NULL;
>               g_io_channel_read_line ( ioc, &line, NULL, NULL, NULL );
>               if (line != NULL )
>               {
>                       //Write the content the bzip extracted file, line after line, to
> the file choosen by the user
>                       fwrite ( line, 1, strlen(line) , fd );
>                       g_free (line);
>               }
>               return TRUE;
>       }
>       else if (cond & (G_IO_ERR | G_IO_HUP | G_IO_NVAL) )
>       {
>               fclose ( fd );
>               g_io_channel_unref (ioc);
>               g_io_channel_shutdown ( ioc,TRUE,NULL );
>               g_spawn_close_pid ( child_pid );
>               return FALSE;
>       }
> }

The following things come to mind in relation to your code:

1.  Have you set the GIOChannel encoding to null (necessary to read binary 
data rather than text)?  (Read the documentation for 
g_io_channel_unix_new().)

2.  If it is binary data you are reading, then you should not use 
g_io_channel_read_line() (whether there are line marker characters in the 
data stream would be entirely arbitrary in that case).  If you insist on 
using GIOChannel then use g_io_channel_read_chars() (after turning off code 
conversion).

3.  You are not doing any error checking, and in particular you are not 
checking the return value of the GIOChannel read function.

Chris