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digitalmars.D.learn - Get files from directory sorted by name

reply Dr.No <jckj33 gmail.com> writes:
Is there something implemented already to get the files from 
directory by name using D or I'm on my own and I have to write it 
myself? I didn't find how do that with dirEntries()
Apr 25 2018
next sibling parent reply Jonathan M Davis <newsgroup.d jmdavisprog.com> writes:
On Wednesday, April 25, 2018 17:34:41 Dr.No via Digitalmars-d-learn wrote:

 Is there something implemented already to get the files from
 directory by name using D or I'm on my own and I have to write it
 myself? I didn't find how do that with dirEntries()


There is nothing in the standard library for doing it, though maybe someone
has something on code.dlang.org. However, the underlying OS API doesn't
exactly conform well to that particular use case. AFAIK, given how the C
APIs work, the only option is to get the list of files and then sort it,
which could be done easily enough with dirEntries. Something as simple as

auto files = dirEntries(dir, SpanMode.shallow).array();
sort!((a, b) => a.name < b.name)(files);

would give you a sorted DirEntry[] of all of the directories and files
directly in the directory. SpanMode.depth or SpanMode.breadth could be used
instead if you want sub-directories, and std.algorithm.iteration.filter
could be used if you want to do something like filter out directories.
std.algorithm.iteration.map could be used if you just want the file names.
So, if you wanted just the names, you could do

auto files = dirEntries(dir, SpanMode.shallow).map!(a => a.name)().array();
sort(files);

though you'd need to use std.path.baseName if you didn't want the full path
- e.g. map!(a => a.name.baseName)(). If you wanted just files, you could do
something like

auto files = dirEntries(dir, SpanMode.shallow).
             filter!(a => a.isFile()).array();
sort!((a, b) => a.name < b.name)(files);

or

auto files = dirEntries(dir, SpanMode.shallow).
             filter!(a => a.isFile()).map!(a => a.name).array();
sort(files);

Exactly which combination of functions you use depends on what you want for
the end result. But the key thing is that you use std.array.array to convert
the forward range into a dynamic array so that std.algorithm.sorting.sort
can sort it (since it requires a random-access range). I really don't think
that you're going to find any other way to do this other than someone who
has written a function that just ends up doing the same thing by wrapping a
call to dirEntries or the underlying C API.

- Jonathan M Davis
Apr 25 2018
parent Dr.No <jckj33 gmail.com> writes:
On Wednesday, 25 April 2018 at 18:06:07 UTC, Jonathan M Davis 
wrote:

 On Wednesday, April 25, 2018 17:34:41 Dr.No via 
 Digitalmars-d-learn wrote:

 Is there something implemented already to get the files from 
 directory by name using D or I'm on my own and I have to write 
 it myself? I didn't find how do that with dirEntries()


 There is nothing in the standard library for doing it, though 
 maybe someone has something on code.dlang.org. However, the 
 underlying OS API doesn't exactly conform well to that 
 particular use case. AFAIK, given how the C APIs work, the only 
 option is to get the list of files and then sort it, which 
 could be done easily enough with dirEntries. Something as 
 simple as

 auto files = dirEntries(dir, SpanMode.shallow).array();
 sort!((a, b) => a.name < b.name)(files);

 would give you a sorted DirEntry[] of all of the directories 
 and files directly in the directory. SpanMode.depth or 
 SpanMode.breadth could be used instead if you want 
 sub-directories, and std.algorithm.iteration.filter could be 
 used if you want to do something like filter out directories. 
 std.algorithm.iteration.map could be used if you just want the 
 file names. So, if you wanted just the names, you could do

 auto files = dirEntries(dir, SpanMode.shallow).map!(a => 
 a.name)().array();
 sort(files);

 though you'd need to use std.path.baseName if you didn't want 
 the full path
 - e.g. map!(a => a.name.baseName)(). If you wanted just files, 
 you could do
 something like

 auto files = dirEntries(dir, SpanMode.shallow).
              filter!(a => a.isFile()).array();
 sort!((a, b) => a.name < b.name)(files);

 or

 auto files = dirEntries(dir, SpanMode.shallow).
              filter!(a => a.isFile()).map!(a => a.name).array();
 sort(files);

 Exactly which combination of functions you use depends on what 
 you want for the end result. But the key thing is that you use 
 std.array.array to convert the forward range into a dynamic 
 array so that std.algorithm.sorting.sort can sort it (since it 
 requires a random-access range). I really don't think that 
 you're going to find any other way to do this other than 
 someone who has written a function that just ends up doing the 
 same thing by wrapping a call to dirEntries or the underlying C 
 API.

 - Jonathan M Davis


I have had just called sort, to later realize the sort wasn't in 
the way humans expect (which is the way Windows Explorer does) so 
I eventually reached 
https://blog.codinghorror.com/sorting-for-humans-natural-sort-order/ but I
failed to call StrCmpLogicalW() from core.sys.windows.shlwapi or link on my own:

pragma(lib, "Shlwapi.lib")
extern(Windows) int StrCmpLogicalW(
   PCWSTR psz1,
   PCWSTR psz2
);

but I got links error so I went to implement StrCmpLogicalW() on 
my own and sorted like this:

auto files = dirEntries(inputDir, SpanMode.shallow).array();
// natural sort
sort!((a, b) => StrCmpLogical(a, b) < 0)(files);

which resulted in the files in same way as Windows 
Explorer/Natural sort.
Apr 26 2018
prev sibling parent reply Jesse Phillips <Jesse.K.Phillips+D gmail.com> writes:
On Wednesday, 25 April 2018 at 17:34:41 UTC, Dr.No wrote:

 Is there something implemented already to get the files from 
 directory by name using D or I'm on my own and I have to write 
 it myself? I didn't find how do that with dirEntries()


I want to add that sorting can be done, if you just call 
std.algorithm.sort you'll find that file names with numbers in 
them will be sorted as a well strings.

Newfile1.txt
Newfile10.txt
Newfile2.txt
Apr 25 2018
parent reply Dr.No <jckj33 gmail.com> writes:
On Wednesday, 25 April 2018 at 19:25:11 UTC, Jesse Phillips wrote:

 On Wednesday, 25 April 2018 at 17:34:41 UTC, Dr.No wrote:

 Is there something implemented already to get the files from 
 directory by name using D or I'm on my own and I have to write 
 it myself? I didn't find how do that with dirEntries()


 I want to add that sorting can be done, if you just call 
 std.algorithm.sort you'll find that file names with numbers in 
 them will be sorted as a well strings.

 Newfile1.txt
 Newfile10.txt
 Newfile2.txt


I've had realized that then implemented natural sort
Apr 26 2018
parent reply Jesse Phillips <Jesse.K.Phillips+D gmail.com> writes:
On Thursday, 26 April 2018 at 16:59:45 UTC, Dr.No wrote:

 On Wednesday, 25 April 2018 at 19:25:11 UTC, Jesse Phillips 
 wrote:

 On Wednesday, 25 April 2018 at 17:34:41 UTC, Dr.No wrote:

 Is there something implemented already to get the files from 
 directory by name using D or I'm on my own and I have to 
 write it myself? I didn't find how do that with dirEntries()


 I want to add that sorting can be done, if you just call 
 std.algorithm.sort you'll find that file names with numbers in 
 them will be sorted as a well strings.

 Newfile1.txt
 Newfile10.txt
 Newfile2.txt


 I've had realized that then implemented natural sort


Thats what it was called. Looks like Rosetta Code has an 
implementation.

https://rosettacode.org/wiki/Natural_sorting#D
Apr 27 2018
parent Dr.No <jckj33 gmail.com> writes:
On Friday, 27 April 2018 at 14:48:00 UTC, Jesse Phillips wrote:

 On Thursday, 26 April 2018 at 16:59:45 UTC, Dr.No wrote:

 On Wednesday, 25 April 2018 at 19:25:11 UTC, Jesse Phillips 
 wrote:

 On Wednesday, 25 April 2018 at 17:34:41 UTC, Dr.No wrote:

 Is there something implemented already to get the files from 
 directory by name using D or I'm on my own and I have to 
 write it myself? I didn't find how do that with dirEntries()


 I want to add that sorting can be done, if you just call 
 std.algorithm.sort you'll find that file names with numbers 
 in them will be sorted as a well strings.

 Newfile1.txt
 Newfile10.txt
 Newfile2.txt


 I've had realized that then implemented natural sort


 Thats what it was called. Looks like Rosetta Code has an 
 implementation.

 https://rosettacode.org/wiki/Natural_sorting#D


I've tried here and that implmentation doesn't yield same result 
as Windows Explorer...
Apr 27 2018