Hackers Magazine 57/CdHackersMagazineNr57.iso/Software/Networking/nmap-5.00-setup.exe/nselib/tab.lua

Text File | 2009-07-06 | 3KB | 126 lines

--- Arrange output into tables.
--
-- This module provides NSE scripts with a way to output structured tables
-- similar to what <code>NmapOutputTable.cc</code> provides.
--
-- Example usage:
-- <code>
-- local t = tab.new(2)
-- tab.add(t, 1, 'A1')
-- tab.add(t, 2, 'A2')
-- tab.nextrow(t)
-- tab.add(t, 1, 'BBBBBBBBB1')
-- tab.add(t, 2, 'BBB2')
-- tab.dump(t)
-- </code>
-- @copyright Same as Nmap--See http://nmap.org/book/man-legal.html

module(... or "tab",package.seeall)

require('strbuf')

--- Create and return a new table with a given number of columns and
-- the row counter set to 1.
-- @param cols The number of columns the table will hold.
-- @return A new table.
function new(cols)
    assert(cols > 0)
    local table ={}

    table['cols'] = cols
    table['rows'] = 1
    setmetatable(table, {__tostring=dump})
    return table
end

--- Add a new string item to a table at a given column position.
--
-- The item will be added to the current row. If <code>nextrow</code> hasn't
-- been called yet that will be row 1.
-- @param t The table.
-- @param v The string to add.
-- @param c The column position at which to add the item.
function add(t, c, v)
    assert(t)
    assert(v)
    assert(t['rows'])
    assert(t['cols'])
    assert(type(v) == "string")

    if c < 1 or c > t['cols'] then
        return false
    end

    -- add a new row if one doesn't exist
    if t[t['rows']] == nil then
        t[t['rows']] = {}
    end

    t[t['rows']][c] = v
    return true
end

--- Add a complete row to the table and move on to the next row.
--
-- Calls <code>add</code> for each argument starting with the second argument
-- and after that calls <code>nextrow</code>.
-- @param t The table.
-- @param ... The elements to add to the row.
function addrow(t, ...)
    for i=1, select("#", ...) do
        add( t, i, tostring( ( select(i, ...)) ) )
    end
    nextrow( t )
end

--- Move on to the next row in the table. If this is not called
-- then previous column values will be over-written by subsequent
-- values.
-- @param t The table.
function nextrow(t)
    assert(t)
    assert(t['rows'])
    t['rows'] = t['rows'] + 1
end

--- Return a formatted string representation of the table.
--
-- The number of spaces in a column is based on the largest element in the
-- column with an additional two spaces for padding.
-- @param t The table.
function dump(t)
    assert(t)
    assert(t['rows'])
    assert(t['cols'])

    local col_len = {}
    local table = strbuf.new()
    local len

    -- find largest string in column
    for i=1, t['cols'] do
        local max = 0
        for x=1, t['rows'] do
            if t[x] == nil then t[x] = {} end
            if t[x][i] ~= nil and string.len(t[x][i]) > max then
                max = string.len(t[x][i])
            end
        end
        col_len[i] = max+2
    end

    -- build table with padding so all column elements line up
    for i=1,t['rows'] do
        for x=1, t['cols'] do
            if t[i][x] ~= nil then
                length = string.len(t[i][x])
                table = table .. t[i][x]
                table = table .. string.rep(' ', col_len[x]-length)
            end
        end
        table = table .. "\n"
    end

    return strbuf.dump(table)
end