`pdfcompress`

pdfcompress batch-compresses PDF files and keeps the originals.

What It Does

takes one or more PDF filenames as arguments
shows the file list and a count, then waits for confirmation before doing anything
compresses each PDF via qpdf --linearize piped into pdftk ... compress
moves the original (pre-compression) copies into an orig/ subfolder

Install qpdf and pdftk via your package manager first, then run against one or more files:

pdfcompress file1.pdf file2.pdf

Compress every PDF in the current directory:

pdfcompress *.pdf

Compress a single file:

pdfcompress report.pdf

Requires at least one filename argument — running it with none prints a short message and exits.
Prompts once with a file list and count, then waits for Enter (or Ctrl+C to cancel) before compressing.
Originals end up in ./orig/ (created if it doesn't exist yet); the compressed file replaces the original filename in place.

Compression happens via a temporary .uncompressed copy of each file in the current directory before the move into orig/ — don't rely on filenames matching *.pdf.uncompressed for anything else while this is running.
No dry-run mode; review the file list shown at the confirmation prompt before pressing Enter.