ACF Libraries

From Alpine Linux
Revision as of 18:19, 8 July 2008 by Ttrask (talk | contribs) (session.lua)
Jump to: navigation, search

ACF Libraries

Because of using lua, a very small language, the need arises to build everything from scratch. This can lead to some confusion, apprehension, or just feeling overwhelmed. Here is documentation on what we have now in the form of libraries and common functions. We hope to build some more and use this information to get the juices flowing in regard to ACF.

Some of these are lua libs or ones written for ACF. We are also using as a standard the lposix library which is documented here LPOSIX


Date and time functions To be used with os.time() and

  • date_to_seconds - Takes a date table and converts it to seconds from 1970
  • seconds_to_date - Takes table of seconds values and converts to a date sorted smallest to largest
  • date_diff - Takes two values of seconds and gives back the difference
  • num_month_name - Month number to name of month
  • num_month_name_abr - Month number to abr of month
  • name_month_num -Month name to number
  • abr_month_num -Month abbreviation to number
  • num_dow_name -Day of Week number to name
  • num_dow_abr - Day of week number to abbreviation
  • name_dow_num -Day of Week full name to number
  • name_dow_num -Day of week abbreviation to number
  • what_tz - Checks to see what timezone the box is set to; /etc/TZ
  • change_tz - Changes the timezone
    • Tables are included with this information
      • Timezones
      • Days of Week
      • Months of the Year


Used for various filesystem specific functions

  • is_dir - test if the a directory
  • is_file - test if is a file
  • is_link - test if file is a link
  • read_file / read_file_as_array - will read a file as a string / array
  • write_file - replace contents of a file
  • write_line_file - appends lines to a file
  • find - Give a path and a filename and search for it
  • md5sum_file - give a hash, md5sum of a file


Used to format table,string,input,output ...

  • dostounix - converts dos line endings to unix
  • remove_blanks_comments - takes out the blank and commented lines
  • table_to_string - formally the join.lua takes a table and makes into a string with delimiter
  • string_to_table - formally split.lua. takes a delimited string and turns it into a table
  • search_replace - will go through a file or table and search and replace
  • search_for_lines - will go through a file and return a table with matches
  • cap_begin_word - will capitalize beginning of words


Functions used by web_elements.lua. Written by nangel for ACF.

  • cookie.set -creates a cookie to be used with ACF
  • html_escape - will escape html encoded strings
  • nv_pair - returns name value pairings as string
  • entity
  • link
  • cfe_unpack - returns the whole of a cfe as a string. Great for troubleshooting.
  • Form setup functions - also are the "types" of cfe. See ACF_core_principles
    • form.text
    • form.longtext
    • form.passwd
    • form.hidden
    • form.submit
    • form.action
    • form.file
    • form.image
    • form.checkbox
    • form.start
    • form.stop


Written by nangel for ACF



find the process ID of a running program



  • program

OUTPUT returns the PID's of running program or nil if there are none.


require "pidof"
if pidof.pidof("mini_httpd") ~= nil then
  print("mini_httpd is running")
  print("mini_httpd is not running")



Drop privileges while allowing a few functions still have root permissions.

privsep.drop_privs(user, group, functable)

Depends on posix and json.


  • user
  • group
  • functable
    • a table of functions that will run as root

OUTPUT: returns a table identical to functable, except the funcs are wrapped and runs in a separate process with root permissions.


#!/usr/bin/env lua

require "posix" 
require "privsep"

-- register those as privileged funcs 
a = {}
function a.getuid()
        return posix.getpid().euid

-- main ---------------------------------------------------------
priv = privsep.drop_privs("nobody", "nogroup", a)
if priv == nil then
        error("failed to drop privileges")

print("current uid:", posix.getpid().euid)
print("privileged uid:", priv.getuid())


Written by nangel for ACF.

  • random_hash - will create a bash64-like hash from /dev/urandom
  • hash_ip_addr - create a hash encoded ip address
  • ip_addr_from_hash - take the hash encoded ip and give me the ip
  • serialize - go through a table or set of tables and serialize
  • save_session - save the session table
  • load_session - load a saved session table
  • unlink_session - delete a saved session table
  • record_event - record an invalid login attempt
  • count_events - check if there are too many invalid attempts
  • expired_events - delete the expired invalid attempts and saved sessions


This contains multiple different functions that each will validate input in there own way.

  • is_ipv4 - test if this is a valid ipv4 address
  • is_mac - test to see if this is a valid mac address
  • is_integer - is the number and int
  • is_integer_in_range - is the int in the range of numbers
  • is_port - the the number in the ip port range


Written by nangel for ACF.

  • render_table -walks through a table rendered for a template
  • render_mainmenu - will render the side menu
  • render_submenu - will render all the sub menu items

split.lua put in format.lua

join.lua put in format.lua