Bob Sneidar wrote:
Not to beat a severely wounded horse, but one reason for implementing
a detailed file function (and probably why it hasn't been tackled) is
that getting the detailed file information from a command shell is
decidedly NOT straightforward.
Shell is great for things we can't do in LiveCode Script yet may not
warrant writing special C-based API interfaces for in LC Builder.
But in addition to the complexity of attempting to rely on such
interprocess communication across platforms, it also carries a certain
impact on memory and performance.
"Why run one process when you can run two at twice the price!" :)
In the enhancement request I cited earlier:
https://quality.livecode.com/show_bug.cgi?id=20384
...Trevor raised a good point about instances where apparently macOS
sometimes disallows access to a folder even while allowing access to
specific files within it. It's hard for me to see how that would not be
a configuration error on any other system, but I trust Apple has a good
reason for that. And in such cases, we're hosed with any current LC
Script solution that needs access to the whole folder's content.
But for the other 99.9% of cases, using a scripted handler reduces the
task to a one-liner, here made even more convenient by allowing either
the detailed info returned in its LC-native comma-delimited format or as
an array if preferred:
on mouseUp
put specialFolderPath("desktop")&"/test/Thisisafilename1000" into tPath
put fwFileInfo( tPath, "Array") into tA
if the result is not empty then
answer the result
else
put the keys of tA
end if
end mouseUp
function fwFileInfo pFile, pArrayFlag
-- Returns info for the file specified in pFile.
-- By default, returns the data in comma-delimited
-- form in the order specified by "detailed files".
-- With any value in the optional pArrayFlag arg
-- it will return an array with descriptive keys.
--
if there is not a file pFile then
return "No such file: "& pFile for error
end if
set the itemdel to "/"
put urlEncode(last item of pFile) into tFileName
put item 1 to -2 of pFile into tPath
put files(tPath, "detailed") into tFiles
if the result is not empty then
return "Error getting file info: "& the result & \
" ("&sysError()&")" for error
end if
put lineoffset(cr& tFileName&",", cr&tFiles) into tLineNum
put line tLineNum of tFiles into tInfo
if pArrayFlag is empty then
return tInfo for value
else
set the itemdel to ","
put 0 into i
put
"name,size,resourceSize,dateCreated,dataModified,dateAccessed,"& \
"dateBackedUp,owner,group,permissions,MacType" into tFields
repeat for each item tItem in tInfo
add 1 to i
if i = 1 then put urlDecode(tItem) into tItem
put tItem into tA[item i of tFields]
end repeat
return tA for value
end if
end fwFileInfo
Performance isn't bad (times shown in ms on Ubuntu 14.04 with Ext4 file
system) - each test was done with the slower form of the function call
that uses the array option:
Folder with 20 files: 0.000072
Folder with 5,000 files: 0.024766
Folder with 10,000 files: 0.042299
I'll leave it as an exercise for the reader to compare with benchmarks
for obtaining the same info via shell. But at a fraction of a
millisecond with LC Script even in an insanely large directory, I'll
wager the time to write the test would exceed any time saved over one's
lifetime. :)
--
Richard Gaskin
Fourth World Systems
Software Design and Development for the Desktop, Mobile, and the Web
____________________________________________________________________
[email protected] http://www.FourthWorld.com
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