Re: [Qemu-devel] [PATCH v4 06/11] qemu-log: support simple pid substitution in logfile

[Aurelien Jarno <aurelien@aurel32.net>]

On 2015-08-03 10:14, Alex Bennée wrote:
> When debugging stuff that occurs over several forks it would be useful
> not to keep overwriting the one logfile you've set-up. This allows a
> simple %d to be included once in the logfile parameter which is
> substituted with getpid().
> 
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Reviewed-by: Leandro Dorileo <l@dorileo.org>
> ---
>  qemu-log.c | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/qemu-log.c b/qemu-log.c
> index 7036076..77ed7bc 100644
> --- a/qemu-log.c
> +++ b/qemu-log.c
> @@ -70,11 +70,24 @@ void do_qemu_set_log(int log_flags, bool use_own_buffers)
>          qemu_log_close();
>      }
>  }
> -
> +/*
> + * Allow the user to include %d in their logfile which will be
> + * substituted with the current PID. This is useful for debugging many
> + * nested linux-user tasks but will result in lots of logs.
> + */
>  void qemu_set_log_filename(const char *filename)
>  {
>      g_free(logfilename);
> -    logfilename = g_strdup(filename);
> +    if (g_strrstr(filename, "%d")) {
> +        /* if we are going to format this we'd better validate first */
> +        if (g_regex_match_simple("^[^%]+%d[^%]+$", filename, 0, 0)) {
> +            logfilename = g_strdup_printf(filename, getpid());
> +        } else {
> +            g_error("Bad logfile format: %s", filename);
> +        }
> +    } else {
> +        logfilename = g_strdup(filename);
> +    }
>      qemu_log_close();
>      qemu_set_log(qemu_loglevel);
>  }

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>


-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                 http://www.aurel32.net