Re: [Qemu-devel] [PATCH v6 5/9] qemu-log: support simple pid substitution in logfile

["Alex Bennée" <alex.bennee@linaro.org>]

Alex Bennée <alex.bennee@linaro.org> writes:

> 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>
> Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
>
> ---
> v5
>   - add another r-b
> ---
>  util/log.c | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/util/log.c b/util/log.c
> index c89b226..3988b5d 100644
> --- a/util/log.c
> +++ b/util/log.c
> @@ -75,11 +75,24 @@ 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")) {

Just realised I missed the strrstr -> strstr fix. Not that it makes a
lot of difference in this case.

> +        /* 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);
>  }


--
Alex Bennée