add tool hsfgrep.lua

luahs-dev-1.rockspec

@@ -19,6 +19,7 @@ Hyperscan is high-performanceregular expression matching library.
 }
 dependencies = {
     "lua >= 5.1",
+    "argparse",
 }
 external_dependencies = {
     HS = {

spec/hsfgrep_spec.lua

@@ -0,0 +1,28 @@
+-- luahs, Lua bindings to hyperscan
+-- Copyright (C) 2016 Boris Nagaev
+-- See the LICENSE file for terms of use.
+
+local luahs = require 'luahs'
+
+describe("hsfgrep.lua", function()
+
+    it("look for multiple expressions in multiple files",
+    function()
+        local expected = [[
+LICENSE	Copyright	9
+LICENSE	20.6	18
+src/luahs/luahs.h	Copyright	48
+src/luahs/luahs.h	20.6	57
+]]
+        local cmd = table.concat({
+            'lua', 'src/bin/hsfgrep.lua',
+            '-p', 'Copyright', '20.6',
+            '-i', 'LICENSE', 'src/luahs/luahs.h',
+        }, ' ')
+        local f = io.popen(cmd, 'r')
+        local observed = f:read('*a')
+        f:close()
+        assert.equal(expected, observed)
+    end)
+
+end)

src/bin/hsfgrep.lua

@@ -0,0 +1,48 @@
+-- luahs, Lua bindings to hyperscan
+-- Copyright (C) 2016 Boris Nagaev
+-- See the LICENSE file for terms of use.
+
+local argparse = require 'argparse'
+local luahs = require 'luahs'
+
+local parser = argparse('hsfgrep', 'Match multiple patterns with Hyperscan')
+parser:option('-p --patterns', 'Patterns'):args('+'):count(1)
+parser:option('-i --input', 'Input files'):args('+'):count(1)
+local args = parser:parse()
+
+local expressions = {}
+for i, pattern in ipairs(args.patterns) do
+    expressions[i] = {
+        expression = pattern,
+        id = i,
+    }
+end
+local db = luahs.compile {
+    expressions = expressions,
+    flags = luahs.pattern_flags.HS_FLAG_DOTALL,
+    mode = luahs.compile_mode.HS_MODE_STREAM,
+}
+local scratch = db:makeScratch()
+local stream = db:makeStream()
+
+for _, filename in ipairs(args.input) do
+
+    local function printHits(hits)
+        local fmt = '%s\t%s\t%d'
+        for _, hit in ipairs(hits) do
+            print(fmt:format(filename, args.patterns[hit.id], hit.to))
+        end
+    end
+
+    local file = io.open(filename, 'r')
+    while true do
+        local chunk = file:read(8192)
+        if not chunk then
+            break
+        end
+        local hits = stream:scan(chunk, scratch)
+        printHits(hits)
+    end
+    local hits = stream:reset(scratch)
+    printHits(hits)
+end