s3cmd Elaborated…

Use –rr option (reduced redundancy) for every put and sync commands !!!. 
Use –bucket-location option to mention nearest geographical location to avoid latency.
To view contents inside a bucket
#s3cmd ls s3://bucketname
To copy/sync a directory into a bucket
#s3cmd sync Desktop/check s3://bucket_name
To view all contents of all buckets one level down (only non empty buckets)
#s3cmd la -H
To sync contents of a local dir in a buckter under an existing directory (s3 object)
#s3cmd sync Desktop/checkunni/ s3://writingz/check/
To sync remote s3 contents to a local directory
#s3cmd sync s3://writingz/check/ Desktop/checkunni/
To sync contents of a local dir in a bucket under a new directory name
#s3cmd sync Desktop/checkunni/ s3://homie/newname/
Here newname directory is created on the fly and files of checkunni are copied inside s3://homie/newname
Copy a non-empty directory (on s3) from one bucket to another bucket
#s3cmd -r cp s3://homie/newname s3://writingz/
Copy a non-empty directory (on s3) from one bucket to another bucket under a new name
#s3cmd -r cp s3://homie/newname s3://writingz/newname2/
To find the size of a bucket/directory
#s3cmd du -H s3://writingz
To download only a single file
#s3cmd get s3://homie/dirname/filename .
To download a remote directory locally.
#s3cmd get -rf s3://writingz/checkunni .
use a / (forward slash) after checkunni to download only the files in it.
To upload a single file
#s3cmd put PSY.mp3 s3://homie/newname/
To upload a local dir to bucket
#s3cmd put -rf s3test s3://homie/newname/
Delete a file
#s3cmd del s3://writingz/abc.jpg
Delete a directory
#s3cmd del -rf s3://writingz/check/
Move a file (can also be used for rename with files only)
#s3cmd mv s3://writingz/abc.png s3://haye/
Move a directory to another bucket 
#s3cmd mv -rf s3://writingz/newname2 s3://haye/
Know the s3cmd version
#s3cmd –version
Make a file public using
#s3cmd put –acl-public hangover3.jpg s3://viewzz/abc.jpg
Make a file private using
#s3cmd setacl –acl-private s3://viewzz/hangover3.jpg
Set all files in a bucket to public/private
#s3cmd setacl –acl-public -r s3://writingz/
If an md5 checksum is need to verify files integrity use
#sudo s3cmd info s3://viewzz/hangover3.jpg (an amazon s3 object)
#md5sum hangover3.jpg (locally downloaded file from s3)
and compare the checksum value.
To delete a bucket (bucket has to be empty use s3cmd del – to delete all files)
#s3cmd rb s3://logix.cz-test (use -f option if bucket is non-empty)
Get various information about Buckets or Files
#s3cmd info s3://BUCKET[/OBJECT]
Other useful options
–delete-removed Delete remote objects with no corresponding local file
[sync]
–no-delete-removed Don’t delete remote objects.
–skip-existing Skip over files that exist at the destination (only
for [get] and [sync] commands).
–continue Continue getting a partially downloaded file (only for
[get] command).
–reduced-redundancy, –rr
Store object with ‘Reduced redundancy’. Lower per-GB
price. [put, cp, mv, sync]
–acl-public Store objects with ACL allowing read for anyone.
–acl-private Store objects with default ACL allowing access for you
only.
–bucket-location=BUCKET_LOCATION Datacentre to create bucket in. Eg :  ap-northeast-1  (Tokyo)
The ACL (Access Control List) of a file can be set at the time of upload using –acl-public or –acl-private options with ‘s3cmd put’ or s3cmd sync’ commands (see below).
Alternatively the ACL can be altered for existing remote files with ‘s3cmd setacl –acl-public’ (or –acl-private) command.
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