On 09/02/2023 07:06, Deborah Brouwer wrote:
> Put the trace file into valid JSON format by removing the trailing comma
> from the trace file array.
>
> Signed-off-by: Deborah Brouwer <deborah.brouwer@xxxxxxxxxxxxx>
> ---
> utils/v4l2-tracer/v4l2-tracer.cpp | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/utils/v4l2-tracer/v4l2-tracer.cpp b/utils/v4l2-tracer/v4l2-tracer.cpp
> index ae6f68e4..7adbe04e 100644
> --- a/utils/v4l2-tracer/v4l2-tracer.cpp
> +++ b/utils/v4l2-tracer/v4l2-tracer.cpp
> @@ -346,7 +346,7 @@ int tracer(int argc, char *argv[], bool retrace)
>
> /* Close the json-array and the trace file. */
> trace_file = fopen(trace_filename.c_str(), "a");
> - fseek(trace_file, 0L, SEEK_END);
> + ftruncate(fileno(trace_file), lseek(fileno(trace_file), 0, SEEK_END) - 2);
> fputs("\n]\n", trace_file);
ftruncate seems overkill to me. Wouldn't it be enough to just do
fseek(trace_file, -2, SEEK_END);
since the fputs afterwards will overwrite those last two characters anyway?
(I think it is -2 for SEEK_END, I'm not 100% certain though, it could be 2)
Regards,
Hans
> fclose(trace_file);
>
