Windows paths in glob

[Dmitry]

OK, so there's a well-known difficulty with handling Windows-style paths in glob: it doesn't
like backslashes, nor does it like spaces. One solution to that is to use Unix-style paths:

glob('C:\Documents and Settings\*'); # Doesn't work
glob('C:/Documents\ and\ Settings/*'); # Works

Problem is, the rest of Perl's built-in file-handling functionality behaves the other way around.
For instance, with -d:

-d 'C:\Documents and Settings'; # Works
-d 'C:/Documents\ and\ Settings'; # Doesn't work

Question: is there any way to use the same path string with glob and with the rest of Perl,
without having to convert them back and forth?

 

[John W. Krahn]

OK, so there's a well-known difficulty with handling Windows-style paths in glob: it doesn't
like backslashes, nor does it like spaces. One solution to that is to use Unix-style paths:

glob('C:\Documents and Settings\*'); # Doesn't work
glob('C:/Documents\ and\ Settings/*'); # Works

Problem is, the rest of Perl's built-in file-handling functionality behaves the other way around.
For instance, with -d:

-d 'C:\Documents and Settings'; # Works
-d 'C:/Documents\ and\ Settings'; # Doesn't work

Question: is there any way to use the same path string with glob and with the rest of Perl,
without having to convert them back and forth?

perldoc File:osGlob
perldoc File::Spec
perldoc File::Basename


John

 

[Martijn Lievaart]

OK, so there's a well-known difficulty with handling Windows-style paths
in glob: it doesn't like backslashes, nor does it like spaces. One
solution to that is to use Unix-style paths:

glob('C:\Documents and Settings\*'); # Doesn't work glob('C:/Documents\
and\ Settings/*'); # Works

Problem is, the rest of Perl's built-in file-handling functionality
behaves the other way around. For instance, with -d:

-d 'C:\Documents and Settings'; # Works -d 'C:/Documents\ and\
Settings'; # Doesn't work

Question: is there any way to use the same path string with glob and
with the rest of Perl, without having to convert them back and forth?

I don't have Windows to test here, but I recall that using either a
forward slash '/' or a backward slash -- properly escaped -- '\\' works
either way in both situations.

In the examples you gave, the versions with backslashes cannot work, the
backslashes are not escaped.

M4

 

[Gunnar Hjalmarsson]

OK, so there's a well-known difficulty with handling Windows-style paths in glob: it doesn't
like backslashes, nor does it like spaces. One solution to that is to use Unix-style paths:

glob('C:\Documents and Settings\*'); # Doesn't work
glob('C:/Documents\ and\ Settings/*'); # Works

Problem is, the rest of Perl's built-in file-handling functionality behaves the other way around.
For instance, with -d:

-d 'C:\Documents and Settings'; # Works
-d 'C:/Documents\ and\ Settings'; # Doesn't work

Question: is there any way to use the same path string with glob and with the rest of Perl,
without having to convert them back and forth?

A long time ago I decided to use opendir() and readdir() instead of
glob(). It may not be as 'elegant', but it works flawlessly without
escaping spaces.

 

[Peter J. Holzer]

I didn't expect that but on second thought it makes sense.

I don't have Windows to test here, but I recall that using either a
forward slash '/' or a backward slash -- properly escaped -- '\\' works
either way in both situations.

You misunderstood the problem. The problem is that glob patterns, like
regexps are mini-languages where some characters (or sequences of
characters) have a special meaning. Just as you cannot just use any
string as a regexp and expect it to match itself (or even be a
well-formed regexp) you cannot use any filename as a glob pattern and
expect it to expand to itself. Actually, for globs the situation is
worse: While any string can be converted to a regexp matching that
string, this is not true for globs. Spaces can be escaped with a
backslash, but I didn't find any way to escape an asterisk or question
mark.

So I guess Gunnar's advice is the best: If you need to deal with
arbitrary file and directory names, avoid glob and use opendir/readdir.
Or maybe File::Find or a similar module (which uses opendir/readdir
internally).

hp

 

[Ben Morrow]

A long time ago I decided to use opendir() and readdir() instead of
glob(). It may not be as 'elegant', but it works flawlessly without
escaping spaces.

To save Uri the trouble of pointing it out , File::Slurp now has a
read_dir function.

Ben

 

[Uri Guttman]

BM> To save Uri the trouble of pointing it out , File::Slurp now has a
BM> read_dir function.

it has always had a read_dir function! its advantages are a simpler API
(no need for a handle, opendir, closedir calls) and it filters out . and
... for you. a minor disadvantage (and very minor IMO) is that it can't
iterate in scalar mode so you get one dir entry at a time. that would
only matter if your dir was enormous and i mean very big.

future plans include passing in a regex or code ref to filter for
you. yeah, you can use grep on the output but it is slightly shorter
that way.

uri

 

[Dmitry]

perldoc File:osGlob
perldoc File::Spec
perldoc File::Basename

I tried DosGlob, but when I passed it 'C:\Documents and Settings\*' it bugged out with an
error somewhere in the module...

 

[Dmitry]

I don't have Windows to test here, but I recall that using either a
forward slash '/' or a backward slash -- properly escaped -- '\\' works
either way in both situations.

In the examples you gave, the versions with backslashes cannot work, the
backslashes are not escaped.

M4

Spaces are a more serious problem than slashes. But anyway, the examples work,
because I used single quotes. BTW, current core glob seems to ignore backslashes
altogether, unless they escape something other than a backslash.

 

[Dmitry]

A long time ago I decided to use opendir() and readdir() instead of
glob(). It may not be as 'elegant', but it works flawlessly without
escaping spaces.

OK, thanks. I guess if I wanted to process wildcards in the file name, I would pass them
through grep?

 

[szr]

OK, so there's a well-known difficulty with handling Windows-style
paths in glob: it doesn't like backslashes, nor does it like spaces.
One solution to that is to use Unix-style paths:

glob('C:\Documents and Settings\*'); # Doesn't work
glob('C:/Documents\ and\ Settings/*'); # Works

Problem is, the rest of Perl's built-in file-handling functionality
behaves the other way around. For instance, with -d:

-d 'C:\Documents and Settings'; # Works
-d 'C:/Documents\ and\ Settings'; # Doesn't work

Question: is there any way to use the same path string with glob and
with the rest of Perl, without having to convert them back and forth?

I find, just as in geenral under Win32, putting double quotes around the
path gets around problems like this:

C:\>perl -e "my @d = glob('"""C:/Documents and Settings"""/*'); print
qq{\n}, join(qq{\n}, @d), qq{\n};"

C:/Documents and Settings/Administrator
C:/Documents and Settings/All Users
[...]

*** Note that """, when used in a double quoted string, under the
cmd.exe shell yields a literal ", so the glob statement is effectively:

glob('"C:/Documents and Settings"/*');

*** This is only because the command was run from the command line; in
an actual script you would of course use a normal double quote around
the path (just like in the linux examples below.)


And this works for tests like -d as well:

C:\>perl -e "print int (-d """C:/Documents and Settings""")"
1
C:\>perl -e "print int (-d """C:/123Documents and Settings""")"
0


And this form works under linux as well:

$ perl -e 'my @d = glob(q{"/mnt/samba/win_hd/Documents and
Settings"/*}); print qq{\n}, join(qq{\n}, @d), qq{\n};'

/mnt/samba/win_hd/Documents and Settings/Administrator
/mnt/samba/win_hd/Documents and Settings/All Users

$ perl -e 'print int (-d "/mnt/samba/win_hd/Documents and Settings")'
1
$ perl -e 'print int (-d "/mnt/samba/win_hd/123Documents and Settings")'
0

This was tested under ActivePerl 5.6.1 and 5.8.7, and under linux using
5.10.0, 5.8.8, and 5.6.1.


So if you want to do it in a way that works on most platforms (at the
very least windows and *nix),

1) Use a forward slash, not a back slash, as a path delimiter.
I.E., C:/path to/somewhere/file.ext, and

2) Surround the path with quotes.
I.E., "C:/path to/somewhere/a long filename.ext", or
"C:/path to/somewhere"/file.ext, or
"C:/Documents and Settings/"

and you should be fine.

Hope this helps.

 

[Bart Lateur]

Question: is there any way to use the same path string with glob and with the rest of Perl,
without having to convert them back and forth?

Is a simple conversion acceptable?

If you put double quotes aroudn the path *in* the string for glob, then
it'll work.

($\, $,) = ("\n", "\t");
chdir 'c:/temp';
foreach('C:/Documents and Settings', 'C:\\Documents and Settings') {
print $_, glob(qq("$_")), -d $_ || 0;
}

Result:

C:/Documents and Settings C:/Documents and Settings 1
C:\Documents and Settings C:./Documents and Settings 1

Well, ok... the response of glob to a backslash *is* weird. But at
least, it seems to work.

 

[Ben Morrow]

Result:

C:/Documents and Settings C:/Documents and Settings 1
C:\Documents and Settings C:./Documents and Settings 1

Well, ok... the response of glob to a backslash *is* weird. But at
least, it seems to work.

Not just weird: wrong. Win32 has a notion of 'current directory on a
given drive'; C:./Documents and Settings is a path relative to the
current directory on drive C:.

Ben