Re: cmp (or echo) bug?

[Houder <houder at xs4all dot nl>]

On 2015-12-25 22:32, David BalaÅic wrote:
> Hi!
>
> In Cygwin terminal (bash) I typed:
>
> cmp  <(echo echo1)  <(echo echo2)
>
> This does not print anything.
> Not even with -b.
>
> On Linux (Ubuntu 12.04 in VMWare) it reports that the inputs are 
> different.
>
> Bug?
> Or am I missing something?

@@ uname -a
CYGWIN_NT-6.1-WOW Seven 2.3.1(0.291/5/3) 2015-11-14 12:42 i686 Cygwin
@@ ./cmp <(echo echo1) <(echo echo2)
/dev/fd/63 /dev/fd/62 differ: byte 5, line 1
@@ ./cmp <(echo echo1) <(echo echo2)
/dev/fd/63 /dev/fd/62 differ: byte 5, line 1
@@ ./cmp <(echo echo1) <(echo echo2)
/dev/fd/63 /dev/fd/62 differ: byte 5, line 1
@@ ./cmp <(echo echo1) <(echo echo2)
/dev/fd/63 /dev/fd/62 differ: byte 5, line 1
@@ ./cmp <(echo echo1) <(echo echo2)
/dev/fd/63 /dev/fd/62 differ: byte 5, line 1
@@ ./cmp <(echo echo1) <(echo echo2)
/dev/fd/63 /dev/fd/62 differ: byte 5, line 1

etc.

But only after I had modified cmp.c (diffutils) as follows:

int
main (int argc, char **argv)
{
...

#if 0
      if (file_desc[f1] < 0 || fstat (file_desc[f1], stat_buf + f1) != 
0)
#else
      if (file_desc[f1] < 0 || f1 ? ( stat (file[1], stat_buf + f1) != 0 
)
                                  : ( stat (file[0], stat_buf + f1) != 0 
) ) // Henri: suspect fstat
#endif
        {
          if (file_desc[f1] < 0 && comparison_type == type_status)
            exit (EXIT_TROUBLE);
          else
            error (EXIT_TROUBLE, errno, "%s", file[f1]);
        }
    }

  /* If the files are links to the same inode and have the same file 
position,
     they are identical.  */

  if (0 < same_file (&stat_buf[0], &stat_buf[1])
      && same_file_attributes (&stat_buf[0], &stat_buf[1])
      && file_position (0) == file_position (1))
{ // Henri: diagnostics
#if 0
    printf("same_file = %d\n", same_file (&stat_buf[0], &stat_buf[1]) );
    printf("same_file_attributes = %d\n", same_file_attributes 
(&stat_buf[0], &stat_buf[1]) );
    printf("same file pos = %d\n", file_position (0) == file_position 
(1) );
#endif
    printf("file[0] = %s, file[1] = %s\n", file[0], file[1]);
    printf("file_desc[0] = %d, file_desc[1] = %d\n", file_desc[0], 
file_desc[1]);
    printf("bailing out: same file.\n");
    return EXIT_SUCCESS;
}

Regards,
Henri


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