cpdf

Merge PDF files

$ cpdf [input1.pdf] [input2.pdf] -o [output.pdf]

$ cpdf [input.pdf] [1-10] -o [output.pdf]

$ cpdf -rotate [90] [input.pdf] -o [output.pdf]

$ cpdf -encrypt [128bit] [owner_password] [user_password] [input.pdf] -o [output.pdf]

$ cpdf -decrypt [input.pdf] owner=[password] -o [output.pdf]

$ cpdf -split [input.pdf] -o [page%%%.pdf]

$ cpdf -scale-page "[2.0 2.0]" [input.pdf] -o [output.pdf]

cpdf [options] input.pdf [pages] -o output.pdf

cpdf (Coherent PDF) is a command-line tool for manipulating PDF files. It can merge, split, encrypt, decrypt, rotate, scale, and perform many other operations on PDF documents without requiring a GUI.
The tool provides precise control over PDF manipulation with support for page ranges, encryption levels, metadata editing, and transformations. It's designed for batch processing, automation, and scenarios where graphical PDF tools are impractical.
cpdf is particularly useful for server-side PDF processing, shell scripts, and workflows requiring reliable, scriptable PDF operations. It handles complex operations like adding watermarks, stamping pages, and manipulating bookmarks.

-o file

Output file path.

Encrypt with specified bit level and passwords.

Decrypt a PDF.

Rotate pages by degrees.

Split into individual pages.

Scale pages by factors.

Merge multiple PDFs.

pdftk(1), qpdf(1), gs(1)