pager.awk

pager.awk

#!/usr/local/bin/gawk -f

BEGIN {
    for (i in ARGV) {
        if (ARGV[i] == "--sep") {
            sep = ARGV[i + 1];
            "echo \'" sep "\'" | getline sep
        }
        ARGV[i] = "";
    }
}
{ 
    for (i = 1; i <= NF; i++) {
        if (field_length[i] < length($i)) {
            field_length[i] = length($i);
        }
    }
    lines[NR] = $0;
}

END {
    "tput cols" | getline cols
    
    if (!sep) {
        longest_line += reduce(field_length, 0, "add");
        gaps = length(field_length) - 1
        excess = cols - longest_line
        sep = sprintf("%-" trunc(excess / gaps) "s", " ")
    }

    for (l in lines) {
        len = split(lines[l], arr, / +/);
        for (i = 1; i <= len; i++) {
            if (i == len) {
                printf "%s", arr[i]
            } else {
                pad = field_length[i];
                printf ("%-" pad "s" sep), arr[i], sep 
            }
        }
        print "";
    }
}

function reduce(arr, initial, f) {
    for (i = 1; i <= length(arr); i++) {
        initial = @f(initial, arr[i])
    }
    return initial;
}

function add(a, b) {
    return a + b;
}

function trunc(num) {
    return sprintf("%.0f", ((num * 10) - ((num * 10) % 10)) / 10) + 0
}