split, merge, extract, repeat: taming PDFs with R

tips

Using pdftools package

Let’s be honest: nobody wakes up excited to work with PDFs.

But sooner or later, we all end up needing to split a 100-page PDF, combine a few PDFs into one, or create a new PDF containing only the pages we actually need.

Meet our hero: pdftools!

In this post, I’ll share a handy little cheat sheet for my future self (and anyone else who stumbles upon this).

Because life is too short to manually wrestle with PDFs, let’s make R do the heavy lifting!

Install and load the package

# install the package (only once!)
install.packages("pdftools")

# load the package (every time you start a new R session!)
library(pdftools)

Combining PDFs (the stapler)

Got three separate PDF files that should have been one?

Instead of uploading them to some random free online tool and hoping your files (and metadata) stay private, just use pdf_combine() in R.

# list of PDFs you want to merge (in order!)
files_to_merge <- c("the_fancy_cover.pdf",
                    "the_actually_important_stuff.pdf",
                    "well_just_in_case.pdf")

# staple them together
pdf_combine(files_to_merge, 
            output = "finally_one_cool_file.pdf")

Yay! Three files, one function, zero sketchy online converters.

Subsetting PDFs (the scissors)

Got a 500-page monster PDF but only need pages 17 through 29?

No need to wrestle with the whole beast. Let pdf_subset() come to the rescue!

# get only pages 17 through 29 (password-protected!)
pdf_subset("giant_monster_file.pdf", 
           pages = 17:29, 
           output = "tiny_piece_of_the_monster_01.pdf",
           password = "string_password_to_open_the_file")

# grab non-consecutive pages (e.g., page 2, 25, and 34)
pdf_subset("giant_monster_file.pdf", 
           pages = c(2, 25, 34), 
           output = "tiny_piece_of_the_monster_02.pdf")

Quick Cheat Sheet

Task	Function	Note
split file	`pdf_split(input, output = NULL, password = "")`	split a single pdf into separate files, one for each page
extract pages	`pdf_subset(input, pages = 1, output = NULL, password = "")`	create a new pdf with a subset of the input pages
combine files	`pdf_combine(input, output = NULL, password = "")`	join several pdf files into one
compress file	`pdf_compress(input, output = NULL, linearize = FALSE, password = "")`	compress or linearize a pdf file
rotate pages	`pdf_rotate_pages(input, pages, angle = 90, relative = FALSE, output = NULL, password = "")`	rotate selected pages

Further information

pdftools documentation