Re: [Vala] A few newbie's questions

[Sandino Flores Moreno <tigrux gmail com>]

To use PACKAGE and VERSION  declare them as extern in your vala source code.

Sorry, I pasted the man page of gets but FileStream.gets is the
wrapper of fgets.

char *fgets(char *s, int size, FILE *stream);
       fgets() reads in at most one less than size characters from stream  and
       stores  them  into  the buffer pointed to by s.  Reading stops after an
       EOF or a newline.  If a newline is read, it is stored into the  buffer.
       A '\0' is stored after the last character in the buffer.

That means that FileStream.gets will stop reading when the buffer size
is reached.
However, fgets does not know of utf-8.

You will have instead to look at the objects in GIO (the glib
input/output objects/functions).

On Thu, Feb 3, 2011 at 5:33 PM, Giulio Paci <giuliopaci gmail com> wrote:
> Hi Sandino,
>
>    thank you for your very quick reply,
>
>
> Il 03/02/2011 23:23, Sandino Flores Moreno ha scritto:
>
> > On Thu, Feb 3, 2011 at 3:27 PM, Giulio Paci <giuliopaci gmail com> wrote:
> > > 1) I tried to create a gstreamer plugin following the Gstreamer Plugin
> > > Writer's Guide
> > > (http://gstreamer.freedesktop.org/data/doc/gstreamer/head/pwg/html/index.html).
> > > I was able to create the plugin, but I was not able to create it using
> > > vala alone, because I was not able to insert in the generated C output
> > > this code:
> > >
> > > #include <glib.h>
> > > #include <gst/gst.h>
> > > GST_PLUGIN_DEFINE (
> > >     GST_VERSION_MAJOR,
> > >      GST_VERSION_MINOR,
> > >      "my_filter",
> > >      "My filter plugin",
> > >      plugin_init,
> > >      VERSION,
> > >      "LGPL",
> > >      "GStreamer",
> > >      "http://gstreamer.net/";
> > >      )
> > >
> > > At last I decided it was not a big issue to put this code in a C file,
> > > but is there any way to directly inject C code in vala?
> > Regarding question 1:
> > ==================
> >
> > Check the next source code:
> > https://github.com/tigrux/gst-plugin-omap4videodecbin/blob/master/gst/gstomap4videodecbin.vala
> >
> > There you can see a line like these:
> > public const Gst.PluginDesc gst_plugin_desc = {
> > ...
> > }
> >
> > That's what you are missing in your gstreamer plugin.
> This is very close to what I wanted.
> What I'm still missing is the possibility to use PACKAGE and VERSION
> macros.
> > > 2) I tried to read a file, one line at time, using the FileStream
> > > object, but I was not able to get the desired result with the current
> > > API, because I needed the whole line (EOL inclusive), while read_line()
> > > removes it. The work around of adding a new line to each line does not
> > > allow to know if the last character of the file was a new line or not.
> > > Is there any way to (easily) read a file including the EOL character?
> > Regarding question 2:
> > ==================
> >
> > Use the method FileStream.gets which corresponds to fgets.
> > public unowned string FileStream.gets (char[] s);
> >
> > > From the man page of fgets:
> >        gets() reads a line from stdin into the buffer pointed to  by  s  until
> >        either  a  terminating newline or EOF, which it replaces with '\0'.  No
> >        check for buffer overrun is performed (see BUGS below).
> >
> >        gets() reads a line from stdin into the buffer pointed to  by  s  until
> >        either  a  terminating newline or EOF, which it replaces with '\0'.  No
> >        check for buffer overrun is performed (see BUGS below).
> This sounds exactly what I need. As I need to have valid utf-8
> characters, do I have to perform any check for the last returned bytes
> (if the line is longer than the char array) or does FileStream.gets
> guarantee that the last returned character is valid?
>
> By the way, Is there a better documentation than
> http://www.valadoc.org/glib-2.0/GLib.FileStream.html? By reading it I
> avoided even trying FileStream.gets as I thought it was just some sort
> of gets and not fgets.
>
> Bests,
>    Giulio.