Re: [PATCH 3/7] strbuf: introduce strbuf_read_cmd helper

Eric Sunshine [off-list ref] writes:

On Sun, Mar 22, 2015 at 6:07 AM, Jeff King [off-list ref] wrote:

quoted

Something as simple as reading the stdout from a command
turns out to be rather hard to do right. Doing:

  if (!run_command(&cmd))
        strbuf_read(&buf, cmd.out, 0);

can result in deadlock if the child process produces a large
amount of output. [...]

Let's introduce a strbuf helper that can make this a bit
simpler for callers to do right.

Signed-off-by: Jeff King <redacted>
---
This is really at the intersection of the strbuf and
run-command APIs, so you could argue for it being part of
either It is logically quite like the strbuf_read_file()
function, so I put it there.

It does feel like a layering violation. If moved to the run-command
API, it could given one of the following names or something better:

    run_command_capture()
    capture_command()
    command_capture()
    run_command_with_output()
    capture_output()

Sound like a good suggestion (but I haven't read the users of the
proposed function, after doing which I might change my mind---I'll
see).

Thanks.