# pdftotext is a command line program that converts PDF files into text files
# first get the pdftotext installer package from http://www.bluem.net/downloads/pdftotext_en/
# pdftotext code written by Glyph & Cog, LLC: http://www.glyphandcog.com/Xpdf.html

which pdftotext     # /usr/local/bin/pdftotext

pdftotext -h
pdftotext example.pdf
pdftotext example.pdf example.txt
pdftotext example.pdf -
pdftotext -layout -eol unix -enc UTF-8 /path/to/file.pdf /path/to/file.txt

Using utilities from the standard teTeX distribution, it's possible to quickly and easily concatenate multiple pdfs together from the command line.

To concatenate 1.pdf, 2.pdf, 3.pdf into a single file 123.pdf you can use the command

texexec --pdfarrange --result 123.pdf 1.pdf 2.pdf 3.pdf

To concatenate all pdf files in a directory into a single file all.pdf you can use

texexec --pdfarrange --result all.pdf *.pdf