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lua-scripting: Revised examples for Lua 5.0. And other updates.

Use admonishment elements, especially WARNING for insecure temporary files.
Don't say anything about enabling system functions.
Linuxgames.com no longer uses <CENTER>.
AppWatch.com was shut down on 2001-08-31.
This commit is contained in:
Kalle Olavi Niemitalo 2007-04-19 00:14:13 +03:00 committed by Kalle Olavi Niemitalo
parent 689d80fada
commit e27a3c3f58
1 changed files with 72 additions and 69 deletions

View File

@ -146,7 +146,7 @@ goto_url_hook (url, current_url)::
that ELinks should follow, or `nil` to cancel the operation.
follow_url_hook (url)::
This hook is passed the URL that Links is about to follow. It should
This hook is passed the URL that ELinks is about to follow. It should
return a string (the URL modified or unmodified), or `nil` to stop
ELinks following the URL
@ -173,7 +173,7 @@ lua_console_hook (string)::
`someprogram`.
- `return "eval", "somefunction(1+2)"` will attempt to call the Lua
function `somefunction` with an argument, 3.
- `return "goto_url", "http://www.bogus.com"` will ask Links to visit
- `return "goto_url", "http://www.bogus.com"` will ask ELinks to visit
the URL "http://www.bogus.com".
- `return nil` will do nothing.
@ -188,7 +188,7 @@ Functions
As well as providing hooks, ELinks provides some functions in addition to the
standard Lua functions.
Note: The standard Lua function `os.setlocale` affects ELinks' idea of
NOTE: The standard Lua function `os.setlocale` affects ELinks' idea of
the system locale, which ELinks uses for the "System" charset, for the
"System" language, and for formatting dates. This may however have to
be changed in a future version of ELinks, in order to properly support
@ -219,21 +219,28 @@ current_document_formatted ([width])::
pipe_read (command)::
Executes `command` and reads in all the data from stdout, until there
is no more. This is a hack, because for some reason the standard Lua
function `read` seems to crash ELinks when used in pipe-reading mode.
function `file:read` seems to crash ELinks when used in pipe-reading
mode.
execute (string)::
Executes shell commands `string` without waiting for it to exit. Beware
that you must not read or write to stdin and stdout. And unlike the
standard Lua function of the same name, the return value is
meaningless.
standard Lua function `os.execute`, the return value is meaningless.
tmpname ()::
Returns a unique name for a temporary file, or `nil` if no
such name is available. The returned string includes the
directory name. This function does not create the file and
does not guarantee exclusive access to it: the caller must
handle the possibility that another process creates the file
and begins using it while this function is returning.
directory name. Unlike the standard Lua function
`os.tmpname`, this one generates ELinks-related names
(currently with "elinks" at the beginning of the name).
+
WARNING: The `tmpname` function does not create the file and does not
guarantee exclusive access to it: the caller must handle the
possibility that another process creates the file and begins
using it while this function is returning. Failing to do this
may expose you to symlink attacks by other users. To avoid
the risk, use `io.tmpfile` instead; unfortunately, it does not
tell you the name of the file.
bind_key (keymap, keystroke, function)::
Currently, `keymap` must be the string `"main"`. Keystroke is a
@ -329,49 +336,48 @@ dialog box, and it will convert them to the URL I actually want to visit. As
a bonus, it allows me perform some searches on sites like Google without
loading up the front page first.
TIP: The ``URI rewriting'' feature of ELinks handles many of the same
tasks as the Lua hook shown here, and you can conveniently configure
it via the option manager. It is not quite as versatile, though.
-------------------------------------------------------------------------------
function match (prefix, url)
return strsub (url, 1, strlen (prefix)) == prefix
return string.sub (url, 1, string.len (prefix)) == prefix
end
function strip (str)
return gsub (str, "^%s*(.-)%s*$", "%1")
return string.gsub (str, "^%s*(.-)%s*$", "%1")
end
function plusify (str)
return gsub (str, "%s", "+")
return string.gsub (str, "%s", "+")
end
function goto_url_hook (url, current_url)
-- Google search (e.g. ,gg unix browsers).
if match (",gg", url) then
url = plusify (strip (strsub (url, 4)))
url = plusify (strip (string.sub (url, 4)))
return "http://www.google.com/search?q="..url.."&btnG=Google+Search"
-- Freshmeat search.
elseif match (",fm", url) then
url = plusify (strip (strsub (url, 4)))
url = plusify (strip (string.sub (url, 4)))
return "http://www.freshmeat.net/search/?q="..url
-- Appwatch search (e.g. ,aw lynx).
elseif match (",aw", url) then
url = plusify (strip (strsub (url, 4)))
return "http://www.appwatch.com/Linux/Users/find?q="..url
-- Dictionary.com search (e.g. ,dict congenial).
elseif match (",dict", url) then
url = plusify (strip (strsub (url, 6)))
url = plusify (strip (string.sub (url, 6)))
return "http://www.dictionary.com/cgi-bin/dict.pl?db=%2A&term="..url
-- RPM search (e.g. ,rpm links).
elseif match (",rpm", url) then
url = plusify (strip (strsub (url, 5)))
url = plusify (strip (string.sub (url, 5)))
return "http://www.rpmfind.net/linux/rpm2html/search.php?query="
..url.."&submit=Search+..."
-- Netcraft.com search (e.g. ,whatis www.google.com).
elseif match (",whatis", url) then
url = plusify (strip (strsub (url, 8)))
url = plusify (strip (string.sub (url, 8)))
return "http://uptime.netcraft.com/up/graph/?host="..url
-- LinuxToday home page.
@ -380,7 +386,7 @@ function goto_url_hook (url, current_url)
-- Weather forecast for Melbourne, Australia.
elseif match (",forecast", url) then
return "http://www.bom.gov.au/cgi-bin/wrap_fwo.pl?IDF02V00.txt"
return "http://www.bom.gov.au/cgi-bin/wrap_fwo.pl?IDV10450.txt"
-- Unmatched
else
@ -389,9 +395,6 @@ function goto_url_hook (url, current_url)
end
-------------------------------------------------------------------------------
(Note that this was noticably enhanced and rewritten in the ELinks standart
hooks.)
Expanding ~ (tilde)
^^^^^^^^^^^^^^^^^^^
@ -402,21 +405,16 @@ and `~user/zappo`, like in the shell
and other Unix programs.
-------------------------------------------------------------------------------
-- Home directory: If you do not enable system functions, you will need
-- to set the following to your home directory.
home_dir = (getenv and getenv ("HOME")) or "/home/MYSELF"
function goto_url_hook (url, current_url)
.
.
-- Expand ~ to home directories.
elseif match ("~", url) then
if strsub(url, 2, 2) == "/" then -- ~/foo
return home_dir..strsub(url, 2)
else -- ~foo/bar
return "/home/"..strsub(url, 2)
if string.sub(url, 2, 2) == "/" then -- ~/foo
return os.getenv ("HOME")..string.sub(url, 2)
else -- ~foo/bar
return "/home/"..string.sub(url, 2)
end
.
@ -436,16 +434,16 @@ use ELinks Lua support to manipulate the HTML before it reaches the parser.
linuxtoday.com
++++++++++++++
Note: This recipe is out of date.
NOTE: This recipe is out of date for the web site.
Linux Today has two problems when viewed in ELinks: the useless columns on the
left and the right and all the text appears in cyan. Here is a quick recipe
to fix that:
-------------------------------------------------------------------------------
-- Plain strfind (no metacharacters)
-- Plain string.find (no metacharacters)
function sstrfind (s, pattern)
return strfind (s, pattern, 1, 1)
return string.find (s, pattern, 1, true)
end
function pre_format_html_hook (url, html)
@ -453,15 +451,15 @@ function pre_format_html_hook (url, html)
-- and change the font colour to white.
if sstrfind (url, "linuxtoday.com") then
if sstrfind (url, "news_story") then
html = gsub (html, '<TABLE CELLSPACING="0".-</TABLE>', '', 1)
html = gsub (html, '<TR BGCOLOR="#FFF.-</TR></TABLE>', '', 1)
html = string.gsub (html, '<TABLE CELLSPACING="0".-</TABLE>', '', 1)
html = string.gsub (html, '<TR BGCOLOR="#FFF.-</TR></TABLE>', '', 1)
else
html = gsub (html, 'WIDTH="120">\n<TR.+</TABLE></TD>', '>', 1)
html = string.gsub (html, 'WIDTH="120">\n<TR.+</TABLE></TD>', '>', 1)
end
html = gsub (html, '<A HREF="http://www.internet.com.-</A>', '')
html = gsub (html, "<IFRAME.-</IFRAME>", "")
html = string.gsub (html, '<A HREF="http://www.internet.com.-</A>', '')
html = string.gsub (html, "<IFRAME.-</IFRAME>", "")
-- emphasis in text is lost
return gsub (html, 'text="#002244"', 'text="#001133"', 1)
return string.gsub (html, 'text="#002244"', 'text="#001133"', 1)
end
return nil
@ -471,6 +469,8 @@ end
linuxgames.com
++++++++++++++
NOTE: This recipe is out of date for the web site.
Here is a simpler example, for link:http://www.linuxgames.com/[].
-------------------------------------------------------------------------------
@ -478,8 +478,8 @@ function pre_format_html_hook (url, html)
.
.
elseif strfind (url, "linuxgames.com", 1, 1) then
return gsub (html, "<CENTER>.-</center>", "", 1)
elseif string.find (url, "linuxgames.com", 1, true) then
return string.gsub (html, "<CENTER>.-</center>", "", 1)
.
.
@ -489,25 +489,27 @@ function pre_format_html_hook (url, html)
Reading gzipped files
^^^^^^^^^^^^^^^^^^^^^
Note: ELinks already supports gzipped files natively.
NOTE: ELinks already supports gzipped files natively.
Sometimes documents come gzipped in order to save space, but then you need to
uncompress them to read them with ELinks. Here is a recipe to handle gzipped
files on a Unix system.
-------------------------------------------------------------------------------
-- This script requires system functions.
WARNING: This recipe opens a temporary file insecurely.
-------------------------------------------------------------------------------
function pre_format_html_hook (url, html)
.
.
-- Handle gzip'd files within reasonable size.
if strfind (url, "%.gz$") and strlen (html) < 65536 then
local tmp = tmpname ()
writeto (tmp) write (html) writeto ()
html = pipe_read ("(gzip -dc "..tmp.." || cat "..tmp..") 2>/dev/null")
remove (tmp)
if string.find (url, "%.gz$") and string.len (html) < 65536 then
local name = tmpname ()
local file = io.open (name, "wb")
file:write (html)
file:close ()
html = pipe_read ("(gzip -dc "..name.." || cat "..name..") 2>/dev/null")
os.remove (name)
return html
end
@ -530,25 +532,27 @@ using `lpr' or `enscript'. Type `lpr()` or `enscript()` in the Lua Console to
run them. (In the `hooks.lua`, I have also made it so you can just type `lpr`
or `enscript`.)
-------------------------------------------------------------------------------
-- This script requires system functions.
NOTE: The `io.popen` function is not available on all platforms.
function catto (output)
writeto (output)
write (current_document_formatted (79))
writeto ()
-------------------------------------------------------------------------------
function pipe_formatted_to (program)
local lp, errmsg = io.popen (program, "w")
if lp == nil then
error (errmsg)
else
lp:write (current_document_formatted (79))
lp:close ()
end
end
-- Send the current document to `lpr'.
function lpr ()
-- You must compile Lua with `popen' support for pipes to work.
-- See `config' in the Lua distribution.
catto ("|lpr")
pipe_formatted_to ("lpr")
end
-- Send the current document to `enscript'.
function enscript ()
catto ("|enscript -fCourier8")
pipe_formatted_to ("enscript -fCourier8")
end
-------------------------------------------------------------------------------
@ -560,9 +564,9 @@ If you come across a brain-dead web page that is totally unreadable with
ELinks, you'd probably want to open it with a graphical browser. The
following function opens the current document in Netscape.
-------------------------------------------------------------------------------
-- This function requires `execute', a system function.
TIP: You can also use the built-in ``URI passing'' feature for this.
-------------------------------------------------------------------------------
-- When starting Netscape: Set to `nil' if you do not want
-- to open a new window for each document.
netscape_new_window = 1
@ -580,13 +584,12 @@ Alternative bookmark system
^^^^^^^^^^^^^^^^^^^^^^^^^^^
Many people would like to have a bookmark system with categories (note that
ELinks already supports that, marketing name Hiearchical bookmarks), and also
ELinks already supports that, marketing name Hierarchical bookmarks), and also
to be able to view them and search for them in an HTML page. I have written
an alternative bookmark system (for ELinks), which some people may like better
than the standard bookmark system.
More ideas
^^^^^^^^^^