1 files changed, 186 insertions, 0 deletions
diff --git a/luaextra-io.lua b/luaextra-io.lua
new file mode 100644
index 0000000..5a126da
--- /dev/null
+++ b/luaextra-io.lua
@@ -0,0 +1,186 @@
+if not modules then modules = { } end modules ['l-io'] = {
+    version   = 1.001,
+    comment   = "companion to luat-lib.mkiv",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+local byte, find, gsub = string.byte, string.find, string.gsub
+
+if string.find(os.getenv("PATH"),";") then
+    io.fileseparator, io.pathseparator = "\\", ";"
+else
+    io.fileseparator, io.pathseparator = "/" , ":"
+end
+
+function io.loaddata(filename,textmode)
+    local f = io.open(filename,(textmode and 'r') or 'rb')
+    if f then
+    --  collectgarbage("step") -- sometimes makes a big difference in mem consumption
+        local data = f:read('*all')
+    --  garbagecollector.check(data)
+        f:close()
+        return data
+    else
+        return nil
+    end
+end
+
+function io.savedata(filename,data,joiner)
+    local f = io.open(filename,"wb")
+    if f then
+        if type(data) == "table" then
+            f:write(table.join(data,joiner or ""))
+        elseif type(data) == "function" then
+            data(f)
+        else
+            f:write(data or "")
+        end
+        f:close()
+        return true
+    else
+        return false
+    end
+end
+
+function io.exists(filename)
+    local f = io.open(filename)
+    if f == nil then
+        return false
+    else
+        assert(f:close())
+        return true
+    end
+end
+
+function io.size(filename)
+    local f = io.open(filename)
+    if f == nil then
+        return 0
+    else
+        local s = f:seek("end")
+        assert(f:close())
+        return s
+    end
+end
+
+function io.noflines(f)
+    local n = 0
+    for _ in f:lines() do
+        n = n + 1
+    end
+    f:seek('set',0)
+    return n
+end
+
+local nextchar = {
+    [ 4] = function(f)
+        return f:read(1,1,1,1)
+    end,
+    [ 2] = function(f)
+        return f:read(1,1)
+    end,
+    [ 1] = function(f)
+        return f:read(1)
+    end,
+    [-2] = function(f)
+        local a, b = f:read(1,1)
+        return b, a
+    end,
+    [-4] = function(f)
+        local a, b, c, d = f:read(1,1,1,1)
+        return d, c, b, a
+    end
+}
+
+function io.characters(f,n)
+    if f then
+        return nextchar[n or 1], f
+    else
+        return nil, nil
+    end
+end
+
+local nextbyte = {
+    [4] = function(f)
+        local a, b, c, d = f:read(1,1,1,1)
+        if d then
+            return byte(a), byte(b), byte(c), byte(d)
+        else
+            return nil, nil, nil, nil
+        end
+    end,
+    [2] = function(f)
+        local a, b = f:read(1,1)
+        if b then
+            return byte(a), byte(b)
+        else
+            return nil, nil
+        end
+    end,
+    [1] = function (f)
+        local a = f:read(1)
+        if a then
+            return byte(a)
+        else
+            return nil
+        end
+    end,
+    [-2] = function (f)
+        local a, b = f:read(1,1)
+        if b then
+            return byte(b), byte(a)
+        else
+            return nil, nil
+        end
+    end,
+    [-4] = function(f)
+        local a, b, c, d = f:read(1,1,1,1)
+        if d then
+            return byte(d), byte(c), byte(b), byte(a)
+        else
+            return nil, nil, nil, nil
+        end
+    end
+}
+
+function io.bytes(f,n)
+    if f then
+        return nextbyte[n or 1], f
+    else
+        return nil, nil
+    end
+end
+
+function io.ask(question,default,options)
+    while true do
+        io.write(question)
+        if options then
+            io.write(string.format(" [%s]",table.concat(options,"|")))
+        end
+        if default then
+            io.write(string.format(" [%s]",default))
+        end
+        io.write(string.format(" "))
+        local answer = io.read()
+        answer = gsub(answer,"^%s*(.*)%s*$","%1")
+        if answer == "" and default then
+            return default
+        elseif not options then
+            return answer
+        else
+            for _,v in pairs(options) do
+                if v == answer then
+                    return answer
+                end
+            end
+            local pattern = "^" .. answer
+            for _,v in pairs(options) do
+                if find(v,pattern) then
+                    return v
+                end
+            end
+        end
+    end
+end