Write more redbean unit tests

- Fix DescribeSigset()
- Introduce new unix.rmrf() API
- Fix redbean sigaction() doc example code
- Fix unix.sigaction() w/ more than two args
- Improve redbean re module API (non-breaking)
- Enhance Lua with Python string multiplication
- Make third parameter of unix.socket() default to 0

test/tool/net/lre_test.lua

@@ -0,0 +1,40 @@
+-- Copyright 2022 Justine Alexandra Roberts Tunney
+--
+-- Permission to use, copy, modify, and/or distribute this software for
+-- any purpose with or without fee is hereby granted, provided that the
+-- above copyright notice and this permission notice appear in all copies.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+-- WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+-- WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+-- AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+-- DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+-- PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+-- TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+-- PERFORMANCE OF THIS SOFTWARE.
+
+m,a,b,c,d = assert(re.search([[^([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})$]], "127.0.0.1"))
+assert(m == "127.0.0.1")
+assert(a == "127")
+assert(b == "0")
+assert(c == "0")
+assert(d == "1")
+
+p = assert(re.compile[[^([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})$]])
+m,a,b,c,d = assert(p:search("127.0.0.1"))
+assert(m == "127.0.0.1")
+assert(a == "127")
+assert(b == "0")
+assert(c == "0")
+assert(d == "1")
+
+m,a,b,c,d = assert(re.search([[\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)]], "127.0.0.1", re.BASIC))
+assert(m == "127.0.0.1")
+assert(a == "127")
+assert(b == "0")
+assert(c == "0")
+assert(d == "1")
+
+p,e = re.compile("[{")
+assert(e:errno() == re.EBRACK)
+assert(e:doc() == "Missing ']'")