Question

LUA中如何获取文件创建时间和修改时间

LUA中如何获取文件创建时间和修改时间
备注：纯LUA语言

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Answer 1

用lua file system 这个库，在lua项目主页可以找到，或者去谷歌。
如果你有安装lua for windows 的话，里面就有。
你可以看这个库的例子，里面有教你查看文件的创建日期与修改日期。

下面是例子：

------------------------------------------------------
local tmp = "/tmp"
local sep = "/"
local upper = ".."

require"lfs"
print (lfs._VERSION)

function attrdir (path)
for file in lfs.dir(path) do
if file ~= "." and file ~= ".." then
local f = path..sep..file
print ("\t=> "..f.." <=")
local attr = lfs.attributes (f)
assert (type(attr) == "table")
if attr.mode == "directory" then
attrdir (f)
else
for name, value in pairs(attr) do
print (name, value)
end
end
end
end
end

-- Checking changing directories
local current = assert (lfs.currentdir())
local reldir = string.gsub (current, "^.*%"..sep.."([^"..sep.."])$", "%1")
assert (lfs.chdir (upper), "could not change to upper directory")
assert (lfs.chdir (reldir), "could not change back to current directory")
assert (lfs.currentdir() == current, "error trying to change directories")
assert (lfs.chdir ("this couldn*t be an actual directory") == nil, "could change to a non-existent directory")

-- Changing creating and removing directories
local tmpdir = current..sep.."lfs_tmp_dir"
local tmpfile = tmpdir..sep.."tmp_file"
-- Test for existence of a previous lfs_tmp_dir
-- that may have resulted from an interrupted test execution and remove it
if lfs.chdir (tmpdir) then
assert (lfs.chdir (upper), "could not change to upper directory")
assert (os.remove (tmpfile), "could not remove file from previous test")
assert (lfs.rmdir (tmpdir), "could not remove directory from previous test")
end

-- tries to create a directory
assert (lfs.mkdir (tmpdir), "could not make a new directory")
local attrib, errmsg = lfs.attributes (tmpdir)
if not attrib then
error ("could not get attributes of file `"..tmpdir.."*:\n"..errmsg)
end
local f = io.open(tmpfile, "w")
f:close()

-- Change access time
local testdate = os.time({ year = 2007, day = 10, month = 2, hour=0})
assert (lfs.touch (tmpfile, testdate))
local new_att = assert (lfs.attributes (tmpfile))
assert (new_att.access == testdate, "could not set access time")
assert (new_att.modification == testdate, "could not set modification time")

-- Change access and modification time
local testdate1 = os.time({ year = 2007, day = 10, month = 2, hour=0})
local testdate2 = os.time({ year = 2007, day = 11, month = 2, hour=0})

assert (lfs.touch (tmpfile, testdate2, testdate1))
local new_att = assert (lfs.attributes (tmpfile))
assert (new_att.access == testdate2, "could not set access time")
assert (new_att.modification == testdate1, "could not set modification time")

local res, err = lfs.symlinkattributes(tmpfile)
if err ~= "symlinkattributes not supported on this platform" then
-- Checking symbolic link information (does not work in Windows)
assert (os.execute ("ln -s "..tmpfile.." _a_link_for_test_"))
assert (lfs.attributes"_a_link_for_test_".mode == "file")
assert (lfs.symlinkattributes"_a_link_for_test_".mode == "link")
assert (os.remove"_a_link_for_test_")
end

if lfs.setmode then
-- Checking text/binary modes (works only in Windows)
local f = io.open(tmpfile, "w")
local result, mode = lfs.setmode(f, "binary")
assert((result and mode == "text") or (not result and mode == "setmode not supported on this platform"))
result, mode = lfs.setmode(f, "text")
assert((result and mode == "binary") or (not result and mode == "setmode not supported on this platform"))
f:close()
end

-- Restore access time to current value
assert (lfs.touch (tmpfile, attrib.access, attrib.modification))
new_att = assert (lfs.attributes (tmpfile))
assert (new_att.access == attrib.access)
assert (new_att.modification == attrib.modification)

-- Remove new file and directory
assert (os.remove (tmpfile), "could not remove new file")
assert (lfs.rmdir (tmpdir), "could not remove new directory")
assert (lfs.mkdir (tmpdir..sep.."lfs_tmp_dir") == nil, "could create a directory inside a non-existent one")

-- Trying to get attributes of a non-existent file
assert (lfs.attributes ("this couldn*t be an actual file") == nil, "could get attributes of a non-existent file")
assert (type(lfs.attributes (upper)) == "table", "couldn*t get attributes of upper directory")

-- Stressing directory iterator
count = 0
for i = 1, 4000 do
for file in lfs.dir (tmp) do
count = count + 1
end
end
print"Ok!"

Answer 2

借花献佛，使用一楼的第一个函数，就可以达到获取文件创建时间和修改时间的目的。
照搬一楼的代码，以下代码实现遍历当前目录及其子目录中文件并打印其属性：
local tmp = "/tmp"
local sep = "/"
local upper = ".."
require"lfs"
print (lfs._VERSION)
function attrdir (path)
for file in lfs.dir(path) do
if file ~= "." and file ~= ".." then
local f = path..sep..file
print ("\t=> "..f.." <=")
local attr = lfs.attributes (f)
assert (type(attr) == "table")
if attr.mode == "directory" then
attrdir (f)
else
for name, value in pairs(attr) do
print (name, value)
end
end
end
end
end
attrdir(".")