On Donnerstag, 26. November 2009, Erik Faye-Lund wrote:
> This patch adds the possibility to supply a non-0
> file descriptor for communucation, instead of the
> default-created pipe. The pipe gets duplicated, so
> the caller can free it's handles.
>
> This is usefull for async communication over sockets.
>
> Signed-off-by: Erik Faye-Lund <kusmabite@xxxxxxxxx>
> ---
> run-command.c | 5 ++++-
> 1 files changed, 4 insertions(+), 1 deletions(-)
>
> diff --git a/run-command.c b/run-command.c
> index e5a0e06..98771ef 100644
> --- a/run-command.c
> +++ b/run-command.c
> @@ -327,7 +327,10 @@ int start_async(struct async *async)
> {
> int pipe_out[2];
>
> - if (pipe(pipe_out) < 0)
> + if (async->out) {
> + pipe_out[0] = dup(async->out);
> + pipe_out[1] = dup(async->out);
> + } else if (pipe(pipe_out) < 0)
> return error("cannot create pipe: %s", strerror(errno));
> async->out = pipe_out[0];
Hm. If async->out != 0:
pipe_out[0] = dup(async->out);
async->out = pipe_out[0];
This is confusing.
Moreover, you are assigning (a dup of) the same fd to the writable end. This
assumes a bi-directional channel. I don't yet know what I should think about
this (haven't studied the later patches, yet).
It would be great if you could add a few words to
Documentation/technical/api-runcommand.txt.
-- Hannes
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