Merge pull request #364 from lunarmodules/cleanup

1 files changed, 141 insertions, 0 deletions

diff --git a/samples/get.lua b/samples/get.lua
new file mode 100644
index 0000000..d53c465
--- /dev/null
+++ b/samples/get.lua
@@ -0,0 +1,141 @@
+-----------------------------------------------------------------------------
+-- Little program to download files from URLs
+-- LuaSocket sample files
+-- Author: Diego Nehab
+-----------------------------------------------------------------------------
+local socket = require("socket")
+local http = require("socket.http")
+local ftp = require("socket.ftp")
+local url = require("socket.url")
+local ltn12 = require("ltn12")
+
+-- formats a number of seconds into human readable form
+function nicetime(s)
+    local l = "s"
+    if s > 60 then
+        s = s / 60
+        l = "m"
+        if s > 60 then
+            s = s / 60
+            l = "h"
+            if s > 24 then
+                s = s / 24
+                l = "d" -- hmmm
+            end
+        end
+    end
+    if l == "s" then return string.format("%5.0f%s", s, l)
+    else return string.format("%5.2f%s", s, l) end
+end
+
+-- formats a number of bytes into human readable form
+function nicesize(b)
+    local l = "B"
+    if b > 1024 then
+        b = b / 1024
+        l = "KB"
+        if b > 1024 then
+            b = b / 1024
+            l = "MB"
+            if b > 1024 then
+                b = b / 1024
+                l = "GB" -- hmmm
+            end
+        end
+    end
+    return string.format("%7.2f%2s", b, l)
+end
+
+-- returns a string with the current state of the download
+local remaining_s = "%s received, %s/s throughput, %2.0f%% done, %s remaining"
+local elapsed_s =   "%s received, %s/s throughput, %s elapsed                "
+function gauge(got, delta, size)
+    local rate = got / delta
+    if size and size >= 1 then
+        return string.format(remaining_s, nicesize(got),  nicesize(rate),
+            100*got/size, nicetime((size-got)/rate))
+    else
+        return string.format(elapsed_s, nicesize(got),
+            nicesize(rate), nicetime(delta))
+    end
+end
+
+-- creates a new instance of a receive_cb that saves to disk
+-- kind of copied from luasocket's manual callback examples
+function stats(size)
+    local start = socket.gettime()
+    local last = start
+    local got = 0
+    return function(chunk)
+        -- elapsed time since start
+        local current = socket.gettime()
+        if chunk then
+            -- total bytes received
+            got = got + string.len(chunk)
+            -- not enough time for estimate
+            if current - last > 1 then
+                io.stderr:write("\r", gauge(got, current - start, size))
+                io.stderr:flush()
+                last = current
+            end
+        else
+            -- close up
+            io.stderr:write("\r", gauge(got, current - start), "\n")
+        end
+        return chunk
+    end
+end
+
+-- determines the size of a http file
+function gethttpsize(u)
+    local r, c, h = http.request {method = "HEAD", url = u}
+    if c == 200 then
+        return tonumber(h["content-length"])
+    end
+end
+
+-- downloads a file using the http protocol
+function getbyhttp(u, file)
+    local save = ltn12.sink.file(file or io.stdout)
+    -- only print feedback if output is not stdout
+    if file then save = ltn12.sink.chain(stats(gethttpsize(u)), save) end
+    local r, c, h, s = http.request {url = u, sink = save }
+    if c ~= 200 then io.stderr:write(s or c, "\n") end
+end
+
+-- downloads a file using the ftp protocol
+function getbyftp(u, file)
+    local save = ltn12.sink.file(file or io.stdout)
+    -- only print feedback if output is not stdout
+    -- and we don't know how big the file is
+    if file then save = ltn12.sink.chain(stats(), save) end
+    local gett = url.parse(u)
+    gett.sink = save
+    gett.type = "i"
+    local ret, err = ftp.get(gett)
+    if err then print(err) end
+end
+
+-- determines the scheme
+function getscheme(u)
+    -- this is an heuristic to solve a common invalid url poblem
+    if not string.find(u, "//") then u = "//" .. u end
+    local parsed = url.parse(u, {scheme = "http"})
+    return parsed.scheme
+end
+
+-- gets a file either by http or ftp, saving as <name>
+function get(u, name)
+    local fout = name and io.open(name, "wb")
+    local scheme = getscheme(u)
+    if scheme == "ftp" then getbyftp(u, fout)
+    elseif scheme == "http" then getbyhttp(u, fout)
+    else print("unknown scheme" .. scheme) end
+end
+
+-- main program
+arg = arg or {}
+if #arg < 1 then
+    io.write("Usage:\n  lua get.lua <remote-url> [<local-file>]\n")
+    os.exit(1)
+else get(arg[1], arg[2]) end