I executed the following command:

s3cmd ls s3://some-bucket-backups/Backup/SCTP/AppData/ | more

I encountered the following bug:

Problem: IOError: [Errno 32] Broken pipe
S3cmd:   1.0.0

Traceback (most recent call last):
  File "/usr/bin/s3cmd", line 2006, in <module>
  File "/usr/bin/s3cmd", line 1950, in main
  File "/usr/bin/s3cmd", line 125, in cmd_ls
    subcmd_bucket_list(s3, uri)
  File "/usr/bin/s3cmd", line 183, in subcmd_bucket_list
    "uri": uri.compose_uri(bucket, object["Key"]),
  File "/usr/bin/s3cmd", line 33, in output
    sys.stdout.write(message + "\n")
  File "/usr/lib64/python2.6/codecs.py", line 352, in write
IOError: [Errno 32] Broken pipe

I found that I got 24736 as the result of the command

s3cmd ls s3://some-bucket-backups/Backup/SCTP/AppData/ | grep -c . 

while the real number of files was varying. In the end, the number of files would be about 38000.

I use the name s3://some-bucket-backups of the bucket to hide the real name of the backet, which I don't want to disclose.