sfdisk, stderr/stdout output order

sfdisk, stderr/stdout output order

[Rüdiger Meier]

Hi,

I've found such test diffs with musl libc. Maybe it needs some fflush(3) 
calls.

 --- /home/rudi/devel/util-linux/tests/expected/sfdisk/dos-read-dump
+++ /tmp/build-musl/tests/output/sfdisk/dos-read-dump
@@ -1,5 +1,3 @@
-Partition 5 does not start on physical sector boundary.
-Partition 6 does not start on physical sector boundary.
 Checking that no-one is using this disk right now ... OK

 Disk <removed>: 50 MiB, 52428800 bytes, 102400 sectors
@@ -23,7 +21,9 @@
 <removed>1  *     2048   8191    6144   3M 83 Linux
 <removed>2        8192  14335    6144   3M 82 Linux swap / Solaris
 <removed>3       14336  20479    6144   3M 83 Linux
-<removed>4       20480 102399   81920  40M  5 Extended
+<removed>4       Partition 5 does not start on physical sector boundary.
+Partition 6 does not start on physical sector boundary.
+20480 102399   81920  40M  5 Extended
 <removed>5       20481  26624    6144   3M 83 Linux
 <removed>6       26626 102399   75774  37M 83 Linux


cu,
Rudi

Re: sfdisk, stderr/stdout output order

[Karel Zak]

On Thu, Mar 10, 2016 at 11:40:50AM +0100, Rüdiger Meier wrote:
> Hi,
> 
> I've found such test diffs with musl libc. Maybe it needs some fflush(3) 
> calls.

 Yes, good point. I'll fix it.

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com

Re: sfdisk, stderr/stdout output order

[Bernhard Voelker]

On 03/10/2016 12:16 PM, Karel Zak wrote:
> On Thu, Mar 10, 2016 at 11:40:50AM +0100, Rüdiger Meier wrote:
>> I've found such test diffs with musl libc. Maybe it needs some fflush(3)
>> calls.
>
>   Yes, good point. I'll fix it.

I don't think you can enforce stdout/stderr to be synchronous.
Well, you can try with "stdbuf(1)", but only having coreutils >v7.5
(2009).  Why not check the output of both streams separately?

Have a nice day,
Berny

Re: sfdisk, stderr/stdout output order

[Karel Zak]

On Thu, Mar 10, 2016 at 03:08:28PM +0100, Bernhard Voelker wrote:
> On 03/10/2016 12:16 PM, Karel Zak wrote:
> >On Thu, Mar 10, 2016 at 11:40:50AM +0100, Rüdiger Meier wrote:
> >>I've found such test diffs with musl libc. Maybe it needs some fflush(3)
> >>calls.
> >
> >  Yes, good point. I'll fix it.
> 
> I don't think you can enforce stdout/stderr to be synchronous.
> Well, you can try with "stdbuf(1)", but only having coreutils >v7.5
> (2009).  Why not check the output of both streams separately?

Well, it's not about tests (although check both streams separately
will be improvement). The problem is that we write to stderr and
stdout in fdisks, fflush(stdout) before warnings will make things 
more deterministic.

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com

Re: sfdisk, stderr/stdout output order

[Rüdiger Meier]

On Thursday 10 March 2016 15:24:50 Karel Zak wrote:
> On Thu, Mar 10, 2016 at 03:08:28PM +0100, Bernhard Voelker wrote:
> > On 03/10/2016 12:16 PM, Karel Zak wrote:
> > >On Thu, Mar 10, 2016 at 11:40:50AM +0100, R=FCdiger Meier wrote:
> > >>I've found such test diffs with musl libc. Maybe it needs some
> > >> fflush(3) calls.
> > >
> > >  Yes, good point. I'll fix it.
> >
> > I don't think you can enforce stdout/stderr to be synchronous.
> > Well, you can try with "stdbuf(1)", but only having coreutils >v7.5
> > (2009).  Why not check the output of both streams separately?
>
> Well, it's not about tests (although check both streams separately
> will be improvement). The problem is that we write to stderr and=20
> stdout in fdisks, fflush(stdout) before warnings will make things
> more deterministic.

Yep, I had found more problems like in rename below. For rename we
should probably fix the test rather than adding fflush().

=2D-- /home/rudi/devel/util-linux/tests/expected/rename/exit_codes
+++ /tmp/build-musl/tests/output/rename/exit_codes=20
@@ -2,6 +2,6 @@
 `rename_exit_codes.1' -> `rename_exit_values.1'
 `rename_exit_codes.2' -> `rename_exit_values.2'
 EXIT_SUCCESS: 0
=2Drename: rename_exit_values.2: rename to rename_exit_codes.2 failed: Is a=
 directory
 `rename_exit_values.1' -> `rename_exit_codes.1'
+rename: rename_exit_values.2: rename to rename_exit_codes.2 failed: Is a d=
irectory
 RENAME_EXIT_SOMEOK: 2

cu,
Rudi