forked from osmocom/wireshark
407b7034e3
The format of the API chapter was a bit screwed up, as was the indentation level of attributes. Also, some functions introduced in 1.11.3 were not documented as being since that version. Change-Id: I7912488c6da5b5ae72933e4c5ce49f8fbf0b0e34 Reviewed-on: https://code.wireshark.org/review/6753 Reviewed-by: Hadriel Kaplan <hadrielk@yahoo.com> Petri-Dish: Hadriel Kaplan <hadrielk@yahoo.com> Reviewed-by: Anders Broman <a.broman58@gmail.com>
676 lines
21 KiB
Text
676 lines
21 KiB
Text
[[wsluarm]]
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// Attributes
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:build_dir: .
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== Lua Support in Wireshark
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[[wsluarm_intro]]
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=== Introduction
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Wireshark has an embedded Lua interpreter. Lua is a powerful light-weight
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programming language designed for extending applications. Lua is designed and
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implemented by a team at PUC-Rio, the Pontifical Catholic University of Rio de
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Janeiro in Brazil. Lua was born and raised at Tecgraf, the Computer Graphics
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Technology Group of PUC-Rio, and is now housed at
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link:http://www.lua.org[Lua.org]. Both Tecgraf and Lua.org are laboratories of
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the Department of Computer Science.
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In Wireshark Lua can be used to write dissectors, taps, and capture file readers
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and writers.
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Wireshark's Lua interpreter starts by loading `init.lua` that is located in the
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global configuration directory of Wireshark. Lua is enabled by default. To
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disable Lua the line variable _$$disable_lua$$_ should be set to _true_ in
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`init.lua`.
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After loading _init.lua_ from the data directory if Lua is enabled Wireshark
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will try to load a file named `init.lua` in the user's directory.
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Wireshark will also load all files with `.lua` suffix from both the global and
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the personal plugins directory.
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The command line option _$$-X lua_script:$$++file.lua++_ can be used to load
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Lua scripts as well.
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The Lua code will be executed once after all the protocol dissectors have being
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initialized and before reading any file.
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[[wslua_dissector_example]]
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=== Example of Dissector written in Lua
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[source,lua]
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----
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local p_multi = Proto("multi","MultiProto");
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local vs_protos = {
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[2] = "mtp2",
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[3] = "mtp3",
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[4] = "alcap",
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[5] = "h248",
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[6] = "ranap",
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[7] = "rnsap",
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[8] = "nbap"
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}
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local f_proto = ProtoField.uint8("multi.protocol","Protocol",base.DEC,vs_protos)
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local f_dir = ProtoField.uint8("multi.direction","Direction",base.DEC,{ [1] = "incoming", [0] = "outgoing"})
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local f_text = ProtoField.string("multi.text","Text")
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p_multi.fields = { f_proto, f_dir, f_text }
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local data_dis = Dissector.get("data")
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local protos = {
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[2] = Dissector.get("mtp2"),
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[3] = Dissector.get("mtp3"),
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[4] = Dissector.get("alcap"),
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[5] = Dissector.get("h248"),
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[6] = Dissector.get("ranap"),
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[7] = Dissector.get("rnsap"),
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[8] = Dissector.get("nbap"),
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[9] = Dissector.get("rrc"),
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[10] = DissectorTable.get("sctp.ppi"):get_dissector(3), -- m3ua
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[11] = DissectorTable.get("ip.proto"):get_dissector(132), -- sctp
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}
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function p_multi.dissector(buf,pkt,root)
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local t = root:add(p_multi,buf(0,2))
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t:add(f_proto,buf(0,1))
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t:add(f_dir,buf(1,1))
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local proto_id = buf(0,1):uint()
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local dissector = protos[proto_id]
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if dissector ~= nil then
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dissector:call(buf(2):tvb(),pkt,root)
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elseif proto_id < 2 then
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t:add(f_text,buf(2))
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-- pkt.cols.info:set(buf(2,buf:len() - 3):string())
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else
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data_dis:call(buf(2):tvb(),pkt,root)
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end
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end
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local wtap_encap_table = DissectorTable.get("wtap_encap")
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local udp_encap_table = DissectorTable.get("udp.port")
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wtap_encap_table:add(wtap.USER15,p_multi)
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wtap_encap_table:add(wtap.USER12,p_multi)
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udp_encap_table:add(7555,p_multi)
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----
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[[wslua_tap_example]]
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=== Example of Listener written in Lua
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[source,lua]
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----
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-- This program will register a menu that will open a window with a count of occurrences
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-- of every address in the capture
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local function menuable_tap()
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-- Declare the window we will use
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local tw = TextWindow.new("Address Counter")
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-- This will contain a hash of counters of appearances of a certain address
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local ips = {}
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-- this is our tap
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local tap = Listener.new();
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function remove()
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-- this way we remove the listener that otherwise will remain running indefinitely
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tap:remove();
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end
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-- we tell the window to call the remove() function when closed
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tw:set_atclose(remove)
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-- this function will be called once for each packet
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function tap.packet(pinfo,tvb)
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local src = ips[tostring(pinfo.src)] or 0
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local dst = ips[tostring(pinfo.dst)] or 0
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ips[tostring(pinfo.src)] = src + 1
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ips[tostring(pinfo.dst)] = dst + 1
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end
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-- this function will be called once every few seconds to update our window
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function tap.draw(t)
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tw:clear()
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for ip,num in pairs(ips) do
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tw:append(ip .. "\t" .. num .. "\n");
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end
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end
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-- this function will be called whenever a reset is needed
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-- e.g. when reloading the capture file
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function tap.reset()
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tw:clear()
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ips = {}
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end
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end
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-- using this function we register our function
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-- to be called when the user selects the Tools->Test->Packets menu
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register_menu("Test/Packets", menuable_tap, MENU_TOOLS_UNSORTED)
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----
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[[wsluarm_modules]]
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== Wireshark's Lua API Reference Manual
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This Part of the User Guide describes the Wireshark specific functions in the embedded Lua.
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include::{build_dir}/wsluarm_src/wslua_dumper.asciidoc[]
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include::{build_dir}/wsluarm_src/wslua_field.asciidoc[]
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include::{build_dir}/wsluarm_src/wslua_gui.asciidoc[]
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include::{build_dir}/wsluarm_src/wslua_listener.asciidoc[]
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include::{build_dir}/wsluarm_src/wslua_pinfo.asciidoc[]
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include::{build_dir}/wsluarm_src/wslua_proto.asciidoc[]
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include::{build_dir}/wsluarm_src/wslua_tree.asciidoc[]
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include::{build_dir}/wsluarm_src/wslua_tvb.asciidoc[]
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include::{build_dir}/wsluarm_src/wslua_file.asciidoc[]
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include::{build_dir}/wsluarm_src/wslua_dir.asciidoc[]
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include::{build_dir}/wsluarm_src/wslua_util.asciidoc[]
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include::{build_dir}/wsluarm_src/wslua_int64.asciidoc[]
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include::{build_dir}/wsluarm_src/wslua_struct.asciidoc[]
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[[lua_module_GRegex]]
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=== GLib Regular Expressions
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Lua has its own native 'pattern' syntax in the string library, but sometimes a
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real regex engine is more useful. Wireshark comes with GLib's Regex
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implementation, which itself is based on Perl Compatible Regular Expressions
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(PCRE). This engine is exposed into Wireshark's Lua engine through the
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well-known Lrexlib library, following the same syntax and semantics as the
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Lrexlib PCRE implementation, with a few differences as follows:
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* There is no support for using custom locale/chartables
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* 'dfa_exec()' doesn't take 'ovecsize' nor 'wscount' arguments
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* 'dfa_exec()' returns boolean true for partial match, without subcapture info
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* Named subgroups do not return name-keyed entries in the return table (i.e., in
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match/tfind/exec)
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* The 'flags()' function still works, returning all flags, but two new functions
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'compile_flags()' and 'match_flags()' return just their respective flags,
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since GLib has a different and smaller set of such flags, for regex compile
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vs. match functions
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* Using some assertions and POSIX character classes against strings with
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non-ASCII characters might match high-order characters, because glib always
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sets PCRE_UCP even if G_REGEX_RAW is set. For example, '[:alpha;]' matches
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certain non-ASCII bytes. The following assertions have this issue: '\b', '\B',
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'\s', '\S', '\w', '\W'. The following character classes have this issue:
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[:alpha:], [:alnum:], [:lower:], [:upper:], [:space:], [:word:], and
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[:graph:].
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* The compile flag G_REGEX_RAW is always set/used, even if you didn't specify
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it. This is because GLib runs PCRE in UTF-8 mode by default, whereas Lua
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strings are not UTF-aware.
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Since: 1.11.3
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This page is based on the full documentation for Lrexlib at
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link:http://rrthomas.github.io/lrexlib/manual.html[http://rrthomas.github.io/lrexlib/manual.html]
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The GLib Regular expression syntax (which is essentially PCRE syntax) can be
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found at
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link:https://developer.gnome.org/glib/2.38/glib-regex-syntax.html[https://developer.gnome.org/glib/2.38/glib-regex-syntax.html]
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[[lua_class_GRegex]]
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==== GRegex
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GLib Regular Expressions based on PCRE.
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Since: 1.11.3
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[[lua_class_GRegex_notes]]
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===== Notes
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All functions that take a regular expression pattern as an argument will
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generate an error if that pattern is found invalid by the regex library.
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All functions that take a string-type regex argument accept a compiled regex
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too. In this case, the compile flags argument is ignored (should be either
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supplied as nils or omitted).
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The capture flag argument 'cf' may also be supplied as a string, whose
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characters stand for compilation flags. Combinations of the following characters
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(case sensitive) are supported:
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* '__i__' = G_REGEX_CASELESS - Letters in the pattern match both upper- and
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lowercase letters. This option can be changed within a pattern by a ``(?i)''
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option setting.
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* '__m__' = G_REGEX_MULTILINE - By default, GRegex treats the strings as
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consisting of a single line of characters (even if it actually contains
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newlines). The ``start of line'' metacharacter (``^'') matches only at the start
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of the string, while the ``end of line'' metacharacter (``$'') matches only at
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the end of the string, or before a terminating newline (unless
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G_REGEX_DOLLAR_ENDONLY is set). When G_REGEX_MULTILINE is set, the ``start of
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line'' and ``end of line'' constructs match immediately following or
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immediately before any newline in the string, respectively, as well as at the
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very start and end. This can be changed within a pattern by a ``(?m)'' option
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setting.
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* '__s__' = G_REGEX_DOTALL - A dot metacharater (``.'') in the pattern matches
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all characters, including newlines. Without it, newlines are excluded. This
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option can be changed within a pattern by a ("?s") option setting.
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* '__x__' = G_REGEX_EXTENDED - Whitespace data characters in the pattern are
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totally ignored except when escaped or inside a character class. Whitespace
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does not include the VT character (code 11). In addition, characters between
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an unescaped ``$$#$$'' outside a character class and the next newline character,
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inclusive, are also ignored. This can be changed within a pattern by a
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``(?x)'' option setting.
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* '__U__' = G_REGEX_UNGREEDY - Inverts the ``greediness'' of the quantifiers so
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that they are not greedy by default, but become greedy if followed by ``?''.
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It can also be set by a ``(?U)'' option setting within the pattern.
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[[lua_fn_GRegex_new_pattern_]]
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===== GRegex.new(pattern)
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Compiles regular expression pattern into a regular expression object whose
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internal representation is corresponding to the library used. The returned
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result then can be used by the methods, e.g. match, exec, etc. Regular
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expression objects are automatically garbage collected.
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Since: 1.11.3
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[float]
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===== Arguments
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pattern:: A Perl-compatible regular expression pattern string
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[float]
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===== Returns
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The compiled regular expression (a userdata object)
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[float]
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===== Errors
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* A malformed pattern generates a Lua error
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[[lua_fn_GRegex_flags__table__]]
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===== GRegex.flags([table])
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Returns a table containing the numeric values of the constants defined by the
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regex library, with the keys being the (string) names of the constants. If the
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table argument is supplied then it is used as the output table, otherwise a new
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table is created. The constants contained in the returned table can then be used
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in most functions and methods where compilation flags or execution flags can be
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specified. They can also be used for comparing with return codes of some
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functions and methods for determining the reason of failure.
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Since: 1.11.3
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[float]
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===== Arguments
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table (optional):: A table for placing results into
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[float]
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===== Returns
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A table filled with the results.
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[[lua_fn_GRegex_compile_flags__table__]]
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===== GRegex.compile_flags([table])
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Returns a table containing the numeric values of the constants defined by the
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regex library for compile flags, with the keys being the (string) names of the
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constants. If the table argument is supplied then it is used as the output
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table, otherwise a new table is created.
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Since: 1.11.3
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[float]
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===== Arguments
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table (optional):: A table for placing results into
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[float]
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===== Returns
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A table filled with the results.
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[[lua_fn_GRegex_match_flags__table__]]
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===== GRegex.match_flags([table])
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Returns a table containing the numeric values of the constants defined by the
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regex library for match flags, with the keys being the (string) names of the
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constants. If the table argument is supplied then it is used as the output
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table, otherwise a new table is created.
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Since: 1.11.3
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[float]
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===== Arguments
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table (optional):: A table for placing results into
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[float]
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===== Returns
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A table filled with the results.
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[[lua_fn_GRegex_match_subject__pattern___init____cf____ef__]]
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===== GRegex.match(subject, pattern, [init], [cf], [ef])
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Searches for the first match of the regexp pattern in the string subject,
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starting from offset init, subject to flags cf and ef. The pattern is compiled
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each time this is called, unlike the class method 'match' function.
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Since: 1.11.3
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[float]
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===== Arguments
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subject:: Subject string to search
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pattern:: A Perl-compatible regular expression pattern string or GRegex object
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init (optional):: start offset in the subject (can be negative)
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cf (optional):: compilation flags (bitwise OR)
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ef (optional):: match execution flags (bitwise OR)
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[float]
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===== Returns
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On success, returns all substring matches ("captures"), in the order they appear
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in the pattern. false is returned for sub-patterns that did not participate in
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the match. If the pattern specified no captures then the whole matched substring
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is returned. On failure, returns nil.
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[[lua_fn_GRegex_find_subject__pattern___init____cf____ef__]]
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===== GRegex.find(subject, pattern, [init], [cf], [ef])
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Searches for the first match of the regexp pattern in the string subject,
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starting from offset init, subject to flags ef. The pattern is compiled each
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time this is called, unlike the class method 'find' function.
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Since: 1.11.3
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[float]
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===== Arguments
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subject:: Subject string to search
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pattern:: A Perl-compatible regular expression pattern string or GRegex object
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init (optional):: start offset in the subject (can be negative)
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cf (optional):: compilation flags (bitwise OR)
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ef (optional):: match execution flags (bitwise OR)
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[float]
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===== Returns
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On success, returns the start point of the match (a number), the end point of
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the match (a number), and all substring matches ("captures"), in the order they
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appear in the pattern. false is returned for sub-patterns that did not
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participate in the match. On failure, returns nil.
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[[lua_fn_GRegex_gmatch_subject__pattern___init____cf____ef__]]
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===== GRegex.gmatch(subject, pattern, [init], [cf], [ef])
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Returns an iterator for repeated matching of the pattern patt in the string
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subj, subject to flags cf and ef. The function is intended for use in the
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generic for Lua construct. The pattern can be a string or a GRegex object
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previously compiled with GRegex.new().
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Since: 1.11.3
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[float]
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===== Arguments
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subject:: Subject string to search
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pattern:: A Perl-compatible regular expression pattern string or GRegex object
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init (optional):: start offset in the subject (can be negative)
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cf (optional):: compilation flags (bitwise OR)
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ef (optional):: match execution flags (bitwise OR)
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[float]
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===== Returns
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The iterator function is called by Lua. On every iteration (that is, on every
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match), it returns all captures in the order they appear in the pattern (or the
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entire match if the pattern specified no captures). The iteration will continue
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till the subject fails to match.
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[[lua_fn_GRegex_gsub_subject__pattern___repl____max____cf____ef__]]
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===== GRegex.gsub(subject, pattern, [repl], [max], [cf], [ef])
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Searches for all matches of the pattern in the string subject and replaces them
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according to the parameters repl and max. The pattern can be a string or a
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GRegex object previously compiled with GRegex.new().
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Since: 1.11.3
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For details see:
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link:http://rrthomas.github.io/lrexlib/manual.html#gsub[http://rrthomas.github.io/lrexlib/manual.html#gsub]
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[float]
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===== Arguments
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subject:: Subject string to search
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pattern:: A Perl-compatible regular expression pattern string or GRegex object
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repl (optional):: Substitution source string, function, table, false or nil
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max (optional):: Maximum number of matches to search for, or control function, or nil
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cf (optional):: Compilation flags (bitwise OR)
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ef (optional):: Match execution flags (bitwise OR)
|
|
|
|
[float]
|
|
===== Returns
|
|
|
|
On success, returns the subject string with the substitutions made, the number
|
|
of matches found, and the number of substitutions made.
|
|
|
|
[[lua_fn_GRegex_split_subject__sep___cf____ef__]]
|
|
|
|
===== GRegex.split(subject, sep, [cf], [ef])
|
|
|
|
Splits a subject string subj into parts (sections). The sep parameter is a
|
|
regular expression pattern representing separators between the sections. The
|
|
function is intended for use in the generic for Lua construct. The function
|
|
returns an iterator for repeated matching of the pattern sep in the string subj,
|
|
subject to flags cf and ef. The sep pattern can be a string or a GRegex object
|
|
previously compiled with GRegex.new(). Unlike gmatch, there will always be at
|
|
least one iteration pass, even if there are no matches in the subject.
|
|
|
|
Since: 1.11.3
|
|
|
|
[float]
|
|
===== Arguments
|
|
|
|
subject:: Subject string to search
|
|
|
|
sep:: A Perl-compatible regular expression pattern string or GRegex object
|
|
|
|
cf (optional):: compilation flags (bitwise OR)
|
|
|
|
ef (optional):: match execution flags (bitwise OR)
|
|
|
|
[float]
|
|
===== Returns
|
|
|
|
The iterator function is called by Lua. On every iteration, it returns a subject
|
|
section (can be an empty string), followed by all captures in the order they
|
|
appear in the sep pattern (or the entire match if the sep pattern specified no
|
|
captures). If there is no match (this can occur only in the last iteration),
|
|
then nothing is returned after the subject section. The iteration will continue
|
|
till the end of the subject.
|
|
|
|
[[lua_fn_GRegex_version__]]
|
|
|
|
===== GRegex.version()
|
|
|
|
Returns a returns a string containing the version of the used library.
|
|
|
|
Since: 1.11.3
|
|
|
|
[float]
|
|
===== Returns
|
|
|
|
The version string
|
|
|
|
[[lua_fn_gregex_match_subject___init____ef__]]
|
|
|
|
===== gregex:match(subject, [init], [ef])
|
|
|
|
Searches for the first match of the regexp pattern in the string subject,
|
|
starting from offset init, subject to flags ef.
|
|
|
|
Since: 1.11.3
|
|
|
|
[float]
|
|
===== Arguments
|
|
|
|
subject:: Subject string to search
|
|
|
|
init (optional):: start offset in the subject (can be negative)
|
|
|
|
ef (optional):: match execution flags (bitwise OR)
|
|
|
|
[float]
|
|
===== Returns
|
|
|
|
On success, returns all substring matches (``captures''), in the order they appear
|
|
in the pattern. false is returned for sub-patterns that did not participate in
|
|
the match. If the pattern specified no captures then the whole matched substring
|
|
is returned. nil is returned if the pattern did not match.
|
|
|
|
[[lua_fn_gregex_find_subject___init____ef__]]
|
|
|
|
===== gregex:find(subject, [init], [ef])
|
|
|
|
Searches for the first match of the regexp pattern in the string subject,
|
|
starting from offset init, subject to flags ef.
|
|
|
|
Since: 1.11.3
|
|
|
|
[float]
|
|
===== Arguments
|
|
|
|
subject:: Subject string to search
|
|
|
|
init (optional):: start offset in the subject (can be negative)
|
|
|
|
ef (optional):: match execution flags (bitwise OR)
|
|
|
|
[float]
|
|
===== Returns
|
|
|
|
On success, returns the start point of the match (a number), the end point of
|
|
the match (a number), and all substring matches ("captures"), in the order they
|
|
appear in the pattern. false is returned for sub-patterns that did not
|
|
participate in the match. On failure, returns nil.
|
|
|
|
[[lua_fn_gregex_exec_subject___init____ef__]]
|
|
|
|
===== gregex:exec(subject, [init], [ef])
|
|
|
|
Searches for the first match of the compiled GRegex object in the string
|
|
subject, starting from offset init, subject to the execution match flags ef.
|
|
|
|
Since: 1.11.3
|
|
|
|
[float]
|
|
===== Arguments
|
|
|
|
subject:: Subject string to search
|
|
|
|
init (optional):: start offset in the subject (can be negative)
|
|
|
|
ef (optional):: match execution flags (bitwise OR)
|
|
|
|
[float]
|
|
===== Returns
|
|
|
|
On success, returns the start point of the first match (a number), the end point
|
|
of the first match (a number), and the offsets of substring matches (``captures''
|
|
in Lua terminology) are returned as a third result, in a table. This table
|
|
contains false in the positions where the corresponding sub-pattern did not
|
|
participate in the match. On failure, returns nil. Example: If the whole match
|
|
is at offsets 10,20 and substring matches are at offsets 12,14 and 16,19 then
|
|
the function returns the following: 10, 20, { 12,14,16,19 }.
|
|
|
|
[[lua_fn_gregex_dfa_exec_subject___init____ef__]]
|
|
|
|
===== gregex:dfa_exec(subject, [init], [ef])
|
|
|
|
Matches a compiled regular expression GRegex object against a given subject
|
|
string subj, using a DFA matching algorithm.
|
|
|
|
Since: 1.11.3
|
|
|
|
[float]
|
|
===== Arguments
|
|
|
|
subject:: Subject string to search
|
|
|
|
init (optional):: start offset in the subject (can be negative)
|
|
|
|
ef (optional):: match execution flags (bitwise OR)
|
|
|
|
[float]
|
|
===== Returns
|
|
|
|
On success, returns the start point of the matches found (a number), a table
|
|
containing the end points of the matches found, the longer matches first, and
|
|
the number of matches found as the third return value. On failure, returns nil.
|
|
Example: If there are 3 matches found starting at offset 10 and ending at
|
|
offsets 15, 20 and 25 then the function returns the following: 10, { 25,20,15 },
|
|
3
|
|
|
|
[[lua_fn_gregex___tostring__]]
|
|
|
|
===== gregex:__tostring()
|
|
|
|
Returns a string containing debug information about the GRegex object.
|
|
|
|
Since: 1.11.3
|
|
|
|
[float]
|
|
===== Returns
|
|
|
|
The debug string
|