Convert PDF files to plain text format.

# To convert filename.pdf to plain text and print it to standard output:
pdftotext filename.pdf -

# To convert filename.pdf to plain text and save it as filename.txt:
pdftotext filename.pdf

# To convert input.pdf to plain text and save it as output.txt:
pdftotext input.pdf output.txt

# To convert pages 2, 3 and 4 of input.pdf to plain text and save them as output.txt:
pdftotext -f 2 -l 4 input.pdf output.txt