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-rw-r--r--lualibs-io.lua105
1 files changed, 77 insertions, 28 deletions
diff --git a/lualibs-io.lua b/lualibs-io.lua
index 66e2793..a9269ab 100644
--- a/lualibs-io.lua
+++ b/lualibs-io.lua
@@ -6,7 +6,10 @@ if not modules then modules = { } end modules ['l-io'] = {
license = "see context related readme files"
}
-local byte, find, gsub = string.byte, string.find, string.gsub
+local io = io
+local byte, find, gsub, format = string.byte, string.find, string.gsub, string.format
+local concat = table.concat
+local type = type
if string.find(os.getenv("PATH"),";") then
io.fileseparator, io.pathseparator = "\\", ";"
@@ -14,16 +17,14 @@ else
io.fileseparator, io.pathseparator = "/" , ":"
end
-function io.loaddata(filename,textmode)
+function io.loaddata(filename,textmode) -- return nil if empty
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
+ if #data > 0 then
+ return data
+ end
end
end
@@ -31,19 +32,59 @@ 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 ""))
+ f:write(concat(data,joiner or ""))
elseif type(data) == "function" then
data(f)
else
f:write(data or "")
end
f:close()
+ io.flush()
return true
else
return false
end
end
+function io.loadlines(filename,n) -- return nil if empty
+ local f = io.open(filename,'r')
+ if f then
+ if n then
+ local lines = { }
+ for i=1,n do
+ local line = f:read("*lines")
+ if line then
+ lines[#lines+1] = line
+ else
+ break
+ end
+ end
+ f:close()
+ lines = concat(lines,"\n")
+ if #lines > 0 then
+ return lines
+ end
+ else
+ local line = f:read("*line") or ""
+ assert(f:close())
+ if #line > 0 then
+ return line
+ end
+ end
+ end
+end
+
+function io.loadchunk(filename,n)
+ local f = io.open(filename,'rb')
+ if f then
+ local data = f:read(n or 1024)
+ f:close()
+ if #data > 0 then
+ return data
+ end
+ end
+end
+
function io.exists(filename)
local f = io.open(filename)
if f == nil then
@@ -66,12 +107,19 @@ function io.size(filename)
end
function io.noflines(f)
- local n = 0
- for _ in f:lines() do
- n = n + 1
+ if type(f) == "string" then
+ local f = io.open(filename)
+ local n = f and io.noflines(f) or 0
+ assert(f:close())
+ return n
+ else
+ local n = 0
+ for _ in f:lines() do
+ n = n + 1
+ end
+ f:seek('set',0)
+ return n
end
- f:seek('set',0)
- return n
end
local nextchar = {
@@ -97,8 +145,6 @@ local nextchar = {
function io.characters(f,n)
if f then
return nextchar[n or 1], f
- else
- return nil, nil
end
end
@@ -107,40 +153,42 @@ local nextbyte = {
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,
+ [3] = function(f)
+ local a, b, c = f:read(1,1,1)
+ if b then
+ return byte(a), byte(b), byte(c)
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,
+ [-3] = function(f)
+ local a, b, c = f:read(1,1,1)
+ if b then
+ return byte(c), byte(b), byte(a)
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
}
@@ -157,12 +205,13 @@ function io.ask(question,default,options)
while true do
io.write(question)
if options then
- io.write(string.format(" [%s]",table.concat(options,"|")))
+ io.write(format(" [%s]",concat(options,"|")))
end
if default then
- io.write(string.format(" [%s]",default))
+ io.write(format(" [%s]",default))
end
- io.write(string.format(" "))
+ io.write(format(" "))
+ io.flush()
local answer = io.read()
answer = gsub(answer,"^%s*(.*)%s*$","%1")
if answer == "" and default then