Read pdf files

readpdf.R

setwd("/I/DON\'T/KNOW/YOUR/COMPUTER")


# Install pdftotext from here: 
# http://mac.softpedia.com/get/Word-Processing/pdftotext-Installer-Package.shtml


# Find pdf files in a directory
get_pdf_files <- function(wd="./")
{
	pdfs <- grep(".pdf$", dir(wd), ignore.case=TRUE, value=TRUE)
	return(pdfs)
}

# Run the pdftotext programme on a pdf file
convert_to_txt <- function(pdffile, eol = "mac")
{
	txtfile <- gsub(".pdf$", ".txt", pdffile)

	# run pdftotext and save the return flag - if not 0 then there was an error
	error <- system(paste("pdftotext -enc UTF-8 -eol", eol, pdffile, txtfile))

	# get rid of control characters
	system(paste("tr -cd '\11\12\15\40-\176' < ", txtfile, " > newfile"))
	system(paste("mv newfile", txtfile))

	return(list(error=error, txtfile=txtfile))
}


# Find all pdfs
pdfs <- get_pdf_files()

# Read each txt file as a vector, each element being a line in the pdf stored as string
# Store each txt file as an element in a list
l <- list()
for(i in 1:length(pdfs))
{
	out <- convert_to_txt(pdfs[i], eol="unix")
	if(out$error == 0)   # If there was no error then try reading the file
	{
		l[[i]] <- readLines(out$txtfile)
	} else {
		l[[i]] <- NULL
	}
}