Get a comma-separted list of color pages in PDF

Question

How do I get a comma-separated list of all color pages in my PDF file?

Thanks to this answer I can get a list of all Page numbers and a note for a color page.

gs -o - -sDEVICE=inkcov input.pdf | grep -v "^ 0.00000  0.00000  0.00000" | \
   grep "^ \|^Page"

The output would be:

Page 1
 0.16646  0.16261  0.14122  0.13507 CMYK OK
Page 2
Page 3
 0.48488  0.48728  0.48794  0.16678 CMYK OK
Page 4
 0.47346  0.47703  0.47624  0.46490 CMYK OK
Page 5

How do I modify the output to return just the pages with color in a comma-separated list?

The result should looks something like that:

1, 3, 4

Answer 1

Okay I find a way to generate a comma-separated list of the color pages in a PDF:

gs -o - -sDEVICE=inkcov test.pdf | \
  grep -v "^ 0.00000  0.00000  0.00000" | \
  grep "^ \|^Page" | \
  paste -sd, | \
  grep -Eo '[0-9]{1,3}, ' | \
  tr -d '\n'

Probably not the most elegant way, but it works.

The code does the following:

• takes the same output like in the question above and replaces the new lines with a comma

  paste -sd,
  

• than it look for numbers between 1-999 followed by a comma (the repalced new line) and an empty space, as the color note always starts with an empty space sign

  grep -Eo '[0-9]{1,3}, '`
  

• at the end it removes ones again the new lines from the output.

  tr -d '\n'
  

• The result would be:

  1, 3, 4,