determine file type

[Mark Gibson]

Is there an equivalent to the unix 'file' command?

[mark tmp]$ file min.txt
min.txt: ASCII text
[mark tmp]$ file trunk
trunk: directory
[mark tmp]$ file compliance.tgz
compliance.tgz: gzip compressed data, from Unix

What I really want to do is determine if a file is 1) a directory, 2) a
text file 3) a binary file.

Is there a way to do this?

Mark

[James Stroud]

Re: determine file type

Mark Gibson wrote:[color=blue]
> Is there an equivalent to the unix 'file' command?
>
> [mark tmp]$ file min.txt
> min.txt: ASCII text
> [mark tmp]$ file trunk
> trunk: directory
> [mark tmp]$ file compliance.tgz
> compliance.tgz: gzip compressed data, from Unix
>
> What I really want to do is determine if a file is 1) a directory, 2) a
> text file 3) a binary file.
>
> Is there a way to do this?
>
> Mark[/color]

import os
def test_file(filen ame, maxread=1024):
if os.path.isdir(f ilename):
return 'directory'
afile = open(filename) # open as text
for achar in afile.read(maxr ead):
if ord(achar) > 127:
return 'binary'
return 'text'


James



--
James Stroud
UCLA-DOE Institute for Genomics and Proteomics
Box 951570
Los Angeles, CA 90095

http://www.jamesstroud.com/

[Mark Gibson]

Re: determine file type

[color=blue]
>
>
> import os
> def test_file(filen ame, maxread=1024):
> if os.path.isdir(f ilename):
> return 'directory'
> afile = open(filename) # open as text
> for achar in afile.read(maxr ead):
> if ord(achar) > 127:
> return 'binary'
> return 'text'
>
>[/color]

Pefect, thanks!

[Steven D'Aprano]

Re: determine file type

On Sun, 26 Mar 2006 19:52:32 -0700, Mark Gibson wrote:
[color=blue]
>[color=green]
>>
>>
>> import os
>> def test_file(filen ame, maxread=1024):
>> if os.path.isdir(f ilename):
>> return 'directory'
>> afile = open(filename) # open as text
>> for achar in afile.read(maxr ead):
>> if ord(achar) > 127:
>> return 'binary'
>> return 'text'
>>
>>[/color]
>
> Pefect, thanks![/color]

Not only is it not perfect, as given it isn't even correct.
[color=blue][color=green][color=darkred]
>>> open("lots_of_n ulls.bin", "w").write( "\0" * 1024)
>>> test_file("lots _of_nulls.bin")[/color][/color][/color]
'text'

However, with a more careful algorithm for deciding what's text and what's
not, the general approach is fine.


--
Steven.