Extract a line-separated list of IPs from a pdf

extract_ips.sh

#!/bin/bash

# Extract a line-separated list of IPs from a pdf
# Assumes the dots are enclosed in square brackets
# -- Cole Hocking

PDF_FILE="$1"
# Reference text file with same basename
FILENAME="$(basename -- "${PDF_FILE}")"
# file extension
EXT="${FILENAME##*.}"
# file name without extension
FILE_HEAD="${FILENAME%.*}"
# Text file conversion
TXT_FILE="${FILE_HEAD}.txt"
# File containing only IPs
IP_FILE="${FILE_HEAD}_ip_list.txt"

# Convert pdf to text file
# requires 'pdftotext'
# (install with: sudo apt install poppler-utils)
convert_pdf(){
    # produces a .txt file with the same name as the pdf
    pdftotext "${PDF_FILE}"
}

# extract IP addresses
extract_ips(){
    # Check to ensure the text file was created
    if [[ -f "${TXT_FILE}" ]]; then
        # Extract only the IPs
        # sed removes the brackets; awk removes the extra line-feed chars
        grep -E '[0-9]{1,3}\[\.\][0-9]{1,3}\[\.\][0-9]{1,3}\[\.\][0-9]{1,3}' "${TXT_FILE}" | sed 's/[][]//g' | awk '/^\014/{sub("\014","")}1' >> "${IP_FILE}"

    else
        echo "${TXT_FILE} -- File not found."
        exit 1
    fi
}

main(){
    if [[ -f ${PDF_FILE} ]]; then
        convert_pdf
        extract_ips
        echo "IP List Created: ${IP_FILE}"
        rm "${TXT_FILE}"
    else
        # check that the pdf file is supplied
        echo "Usage: ./extract_ips.txt <file>.pdf"
        exit 1
    fi
}

main