On Thu, Jun 16, 2016 at 5:37 AM, Jeff King <p...@peff.net> wrote: > We already have capture_command(), which captures the stdout > of a command in a way that avoids deadlocks. But sometimes > we need to do more I/O, like capturing stderr as well, or > sending data to stdin. It's easy to write code that > deadlocks racily in these situations depending on how fast > the command reads its input, or in which order it writes its > output. > > Let's give callers an easy interface for doing this the > right way, similar to what capture_command() did for the > simple case. > > The whole thing is backed by a generic poll() loop that can > feed an arbitrary number of buffers to descriptors, and fill > an arbitrary number of strbufs from other descriptors. This > seems like overkill, but the resulting code is actually a > bit cleaner than just handling the three descriptors > (because the output code for stdout/stderr is effectively > duplicated, so being able to loop is a benefit). > > Signed-off-by: Jeff King <p...@peff.net> > --- > diff --git a/run-command.h b/run-command.h > @@ -79,17 +79,34 @@ int run_command_v_opt(const char **argv, int opt); > /** > - * Execute the given command, capturing its stdout in the given strbuf. > + * Execute the given command, sending "in" to its stdin, and capturing its > + * stdout and stderr in the "out" and "err" strbufs. Any of the three may > + * be NULL to skip processing. > + * > * Returns -1 if starting the command fails or reading fails, and otherwise > - * returns the exit code of the command. The output collected in the > - * buffer is kept even if the command returns a non-zero exit. The hint field > - * gives a starting size for the strbuf allocation. > + * returns the exit code of the command. Any output collected in the
Did you mean s/returns/Returns/ ? > + * buffers is kept even if the command returns a non-zero exit. The hint > fields > + * gives starting sizes for the strbuf allocations. > * > * The fields of "cmd" should be set up as they would for a normal > run_command > - * invocation. But note that there is no need to set cmd->out; the function > - * sets it up for the caller. > + * invocation. But note that there is no need to set the in, out, or err > + * fields; capture_command handles that automatically. s/capture_command/pipe_command/ > + */ > +int pipe_command(struct child_process *cmd, > + const char *in, size_t in_len, > + struct strbuf *out, size_t out_hint, > + struct strbuf *err, size_t err_hint); > + -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
