I wanted to test an external USB HDD 2.5" eIDE drive (WD2500BEVE) which contains a Windows filesystem.
So I issued the following command:
# badblocks -nsv -p2 -o ./badblocksresult_eIDE /dev/sdc

I expected to see the information about the blocks which have already been checked.
Instead, the only output I got is this:
Checking for bad blocks in non-destructive read-write mode
From block 0 to 244198583
Checking for bad blocks (non-destructive read-write test)
Testing with random pattern: 62.97% done, 11:30:00 elapsed

In my original command the -s handle was implicitly specified to show me the blocks which were checked. I also couldn't find out the information by catting the output file, since the output file only specifies the bad blocks.

# fdisk -l
Disk /dev/sdc: 250.1 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders, total 488397168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xbca9bca9

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1   *        2048      206847      102400    7  HPFS/NTFS/exFAT
/dev/sdc2          206848   488394751   244093952    7  HPFS/NTFS/exFAT

# uname -a
Linux lb-U-100 3.0.0-15-generic #26-Ubuntu SMP Fri Jan 20 15:59:53 UTC 2012 i686 i686 i386 GNU/Linux

Is this potential material for a bug report?

Thanks in advance,