ttylynx

#!/bin/bash
#bash wrapper for operating lynx web browser from a hard copy teletype
#also uses wget and jp2a to make ascii art from any jpg images
#alnwlsn 2023

if [[ $# -lt 1 ]]; then
    echo "give URL"
    exit 1
fi
vhist=() #stores visited history, so we can go back
url="$1"
current_url=""
page_content=""
page_size=""
page_lines=""
links_range=""
references=""
last_linknumber=0
url_map=() # Array to store URLs corresponding to numbers
visit() {
    vhist+=("$1")
}
vback() { #go back to last page
    # remove current page
    if [[ ${#vhist[@]} -eq 1 ]]; then
        #echo "at beginning"
        return 1
    fi
    local last_index=$(( ${#vhist[@]} - 1 ))
    unset "vhist[$last_index]"

    #get last page, then remove it (will be added again when we visit the page in a sec)
    if [[ ${#vhist[@]} -eq 0 ]]; then
        #echo "at beginning"
        return 1
    fi
    local last_index=$(( ${#vhist[@]} - 1 ))
    url="${vhist[last_index]}"
    unset "vhist[$last_index]"
    web_update
    echo "$page_size" "$page_lines" "$links_range"
}

web_update(){
    current_url=$url
    if [[ "${url,,}" == *.jpg ]]; then
        #URL is a JPG image. Show ASCII art
        output=$(wget -q "$url" -O- | jp2a --width=60 -)
        visit "$url"
        page_content=$(echo "$output")
        references=""
        links_range="(jpg)"
    else
        output=$(lynx -dump "$url")
        visit "$url"
        # Trim the "References" section from output
        page_content=$(echo "$output" | sed -e '/^References$/,$d')
        #change non-ascii to ?
        page_content=$(echo "$page_content" | LC_ALL=C sed 's/[\x80-\xFF]/?/g')
        # Store the references separately
        references=$(echo "$output" | sed -n -e '/^References$/,$p')
        # Find the greatest number in the references list
        greatest_number=0
        url_map=() # Array to store URLs corresponding to numbers
        while IFS= read -r line; do
            number=$(echo "$line" | awk -F '.' '{print $1}') #get the number from the field
            number=$(echo "$number" | grep -oE '[0-9]+')
            if [ -n "$number" ]; then #make sure it is a number
                if [[ $number -gt $greatest_number ]]; then
                    greatest_number=$number
                fi
                url=$(echo "$line" | grep -oE '[^[:space:]]*://\S+') #add link to table
                url_map[$number]=$url
            fi
        done <<< "$references"

        if [[ $greatest_number -gt 0 ]]; then
            links_range="(1-$greatest_number)"
        else
            links_range=""
        fi
    fi
    page_lines=$(echo -n "$page_content" | grep -c '^')
    page_size=${#page_content}
}
web_update
echo "$page_size" "$page_lines" "$links_range"
while true; do
    read -p ":" input
    if [[ "$input" == "q" ]]; then
        break
    elif [[ "$input" == "p" ]]; then
        echo "$page_content"
    elif [[ "$input" == "r" ]]; then
        echo "$references"
    elif [[ "$input" == "l" ]]; then
        echo "$page_size" "$page_lines" "$links_range"
    elif [[ "$input" == "u" ]]; then
        echo "$current_url"
    elif [[ "$input" == "b" ]]; then
        vback
    elif [[ "$input" == "h" ]]; then
        for value in "${vhist[@]}"
        do
          echo $value
        done
    elif [[ "$input" =~ ^([0-9]+)-([0-9]+)$ ]]; then
        start=${BASH_REMATCH[1]}
        endd=${BASH_REMATCH[2]}
        lenn=$(expr "$start" - "$endd")
        echo "$page_content" | head -n "$endd" | tail -n "$lenn"
    elif [[ "$input" =~ ^[0-9]+$ ]]; then
        if (( input >= 1 && input <= greatest_number )); then
            url="${url_map[$input]}"
            web_update
            echo "$page_size" "$page_lines" "$links_range"
        else
            echo "$links_range"
        fi
    elif [[ "$input" == "?" ]]; then
        echo "Commands:"
        echo "p - print page output"
        echo "(numberA)-(numberB) - print lines of page output between A and B"
        echo "r - print references section"
        echo "l - print page size, number of lines, and range of links "
        echo "u - print current URL"
        echo "(number) - follow link"
        echo "b - go back one link"
        echo "h - show traversal history"
        echo "q - quit"
    fi
done