Super simple and fast delimited CSV data normalization with AWK

#!/usr/bin/awk -f

# This block only runs once at the start, before the first line
# Use this to print CSV header on the top
BEGIN {
    FS="|"; # input field separator
    OFS="|"; # output field separator
}

# This block runs at every line
{
    # We will order a new named variable to every column
    line = $0; # variable `$0` stores the entire line
    url = $1;
    title = $2;
    body = $3
    tags = $4;

    if (line ~ /^$/) next; # if line is blank, then skip it
    if (NF != 4) next; # if column count is not equal to 4, then skip the line

    # Skip any line where tags column contains the word "cars"
    if (index(tags, "cars") != 0) { next; }

    # Normalize the url column with regex by only keeping the article id
    # Example input: <a href="https://example.com/article/foo123456">Hello</a>
    gsub(/.*example\.com\/article\/|[\042].*/, "", url); # outputs: foo123456

    # Skip lines that has non-alphanumeric characters in url column (like <>#&@)
    # Skip lines that has empty url column (after gsub normalization)
    # Skip lines where url starts with foo or bar
    if (url !~ /[[:alnum:]]/ ||
        length(url) == 0 ||
        url ~ /^foo|^bar/) {
        next;
    }

    # Replace multiple ; with one (needed for errorless CSV import in Postgres)
    gsub(/[\073]+/, ";", tags);

    # Print the line with OFS, aka: profit! :)
    print url, title, body, tags;
}