Re: [Qemu-devel] [RISU PATCH v5 10/13] risu: handle trace through stdin/stdout

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

Peter Maydell <peter.maydell@linaro.org> writes:

> On 19 June 2017 at 11:46, Alex Bennée <alex.bennee@linaro.org> wrote:
>> Trace files can get quite large so it would be useful to be able to
>> just capture the trace stream with stdin/stdout for processing in a
>> pipe line. The sort of case where this is useful is for building
>> static binaries where zlib support is missing for whatever reason.
>>
>> It can also be used in testing pipelines.
>>
>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>> ---
>>  risu.c | 12 ++++++++++--
>>  1 file changed, 10 insertions(+), 2 deletions(-)
>>
>> diff --git a/risu.c b/risu.c
>> index 93c274b..e94b54b 100644
>> --- a/risu.c
>> +++ b/risu.c
>> @@ -312,7 +312,11 @@ int main(int argc, char **argv)
>>
>>      if (ismaster) {
>>          if (trace) {
>> -            master_fd = open(trace_fn, O_WRONLY|O_CREAT, S_IRWXU);
>> +            if (strncmp(trace_fn, "-", strlen(trace_fn))==0) {
>
> Why not just strcmp() ?

Years of habit...

>
>> +                master_fd = fileno(stdout);
>
>    = STDOUT_FILENO;

heh , the original version used that. I'll put it back.

>
>> +            } else {
>> +                master_fd = open(trace_fn, O_WRONLY|O_CREAT, S_IRWXU);
>> +            }
>>          } else {
>>              fprintf(stderr, "master port %d\n", port);
>>              master_fd = master_connect(port);
>> @@ -320,7 +324,11 @@ int main(int argc, char **argv)
>>          return master();
>>      } else {
>>          if (trace) {
>> -            apprentice_fd = open(trace_fn, O_RDONLY);
>> +            if (strncmp(trace_fn, "-", strlen(trace_fn))==0) {
>> +                apprentice_fd = fileno(stdin);
>
>  = STDIN_FILENO;
>
>> +            } else {
>> +                apprentice_fd = open(trace_fn, O_RDONLY);
>> +            }
>>          } else {
>>              fprintf(stderr, "apprentice host %s port %d\n", hostname, port);
>>              apprentice_fd = apprentice_connect(hostname, port);
>> --
>> 2.13.0
>>
>
> thanks
> -- PMM


--
Alex Bennée