Checking if a file is in a S3 bucket using the s3cmd

Question

I having a program that successfully uploads all of the files that I need. I have new files everyday that I need to upload. After I have uploaded the files I no longer need

Answer 1

Assuming that bar.txt and bar.txt.bak exist in a bucket s3://foo, "s3cmd ls s3://foo/bar.txt" shows a following output.

$ s3cmd ls s3://foo/bar.txt
2013-11-11 11:11    5   s3://foo/bar.txt
2013-11-11 11:11    5   s3://foo/bar.txt.bak

Since we should remove 2nd line from the command result, we use "awk" command to filter unnecessary lines.

$ filename=s3://foo/bar.txt
$ s3cmd ls ${filename} | awk "\$4 == \"${filename}\" { print \$4 }"
2013-11-11 11:11    5   s3://foo/bar.txt

Finally, we build up all commands.

filename=s3://foo/bar.txt
count=$(s3cmd ls ${filename} | awk "\$4 == \"${filename}\" { print \$4 }" | wc -l)

if [ $count -eq 0 ]; then
  echo "file does not exist"
else
  echo "file exists"
fi