Re: [Tutor] Looking for something similar to du...
Marc Tompkins [EMAIL PROTECTED] wrote Can you explain what you mean by the diffrence between the size used versus the size of the image? Disk space is allocated in large units (in DOS/Windows they're called clusters, *nixes call them blocks). Ah yes, indeed it is. And in a previous life I even used to care about such things! Nowadays I've gotten used to disk space being so cheap and plentiful I confess I'd forgotten all about the diffrences and their significance. Thanks for the reminder Marc. As to finding disk usage on Windows I found this snippet on an MSDN forum: -- If you want the size of the file on disk when compressed or sparse then you have to use Platform/Invoke to call GetCompressedFileSize as I don't believe .NET exposes this method directly. Furthermore this doesn't give you the actual size on disk if it isn't compressed. For that I believe you'd have to determine how many clusters it takes up and multiply that by the cluster size. I don't believe there is any direct way in Windows to do that but WMI might provide a way. Nevertheless this is not what you'd want to use as it'll also contain unused bytes of data. - Which is rather scary... Alan G ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Looking for something similar to du...
On Mon, May 5, 2008 at 11:55 PM, Alan Gauld [EMAIL PROTECTED] wrote: As to finding disk usage on Windows I found this snippet on an MSDN forum: -- If you want the size of the file on disk when compressed or sparse then you have to use Platform/Invoke to call GetCompressedFileSize as I don't believe .NET exposes this method directly. Furthermore this doesn't give you the actual size on disk if it isn't compressed. For that I believe you'd have to determine how many clusters it takes up and multiply that by the cluster size. I don't believe there is any direct way in Windows to do that but WMI might provide a way. Nevertheless this is not what you'd want to use as it'll also contain unused bytes of data. - Which is rather scary... Not really, just written by someone who 1) had something else in mind, or 2) is unclear on the concept. Because _of course_ this number will include unused bytes (not of data, though, just of disk space). It's called slack space, I believe - all those extra bytes between the end of the file and the end of the last cluster allocated to the file. Even with FAT32, NTFS, and many highly-advanced file systems in the *nix world, it adds up to a surprisingly large proportion of most peoples' disk space. (More if you have lots of tiny files, less if you have lots of big files.) That being said, I've recently been buying 500GB hard drives for $100. (And yes, I'm sure there are even hotter deals out there. Don't rub it in if you've found one, though - it'll only make me miserable.) At 20 cents a gig, it's hard to work up any real anxiety over slack space. I'm curious - what does the OP do with this info? Does it have some deeper significance I don't know about, or is it just a cool statistic to track? -- www.fsrtechnologies.com ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Looking for something similar to du...
Marc Tompkins [EMAIL PROTECTED] wrote As to finding disk usage on Windows I found this snippet on an MSDN forum: -- I don't believe there is any direct way in Windows to do that but WMI might provide a way. Nevertheless this is not what you'd want to Which is rather scary... Not really, just written by someone who 1) had something else in mind, I just meant the fact that Microsoft didn't appear to provide an API function to find it directly was scary - especially since its something they report in Explorer as you noted earlier. That being said, I've recently been buying 500GB hard drives for $100. The cost of disk space is frighteningly cheap. I remember buying a Terabyte of storage for a mainframe about 20 years ago and it cost over $2 million. Now I can buy a Terabyte of NAS for $200! That's why I've stopped worrying about lost space due to block sizes! :-) Alan G. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Looking for something similar to du...
Spencer Parker [EMAIL PROTECTED] wrote I am wondering if there is a way to do something that du does in Linux. I have several disk images and I need a way to get the size used...not the size of the image. If you type in du and the disk image path it gives you this number. is there anyway to do this in python? Probably but I'm not totally clear what you are looking for. Can you explain what you mean by the diffrence between the size used versus the size of the image? Surely the size of the image is the space it uses? Or are you expanding compressed files? Can you give an example of the two measures so that we(I?) can better understand the distinction Meantime try looking at the os.walk function and the os.fstat function. That may be all you need. -- Alan Gauld Author of the Learn to Program web site http://www.freenetpages.co.uk/hp/alan.gauld ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Looking for something similar to du...
On Mon, May 5, 2008 at 5:21 PM, Alan Gauld [EMAIL PROTECTED] wrote: Probably but I'm not totally clear what you are looking for. Can you explain what you mean by the diffrence between the size used versus the size of the image? Surely the size of the image is the space it uses? Or are you expanding compressed files? Disk space is allocated in large units (in DOS/Windows they're called clusters, *nixes call them blocks). A one-byte file still uses an entire cluster, whose size depends on the size of the disk and the number of chunks it can be divided into. So just knowing the size of the file is not quite enough information if you need to know how much room is left on the disk... If you use Windows, you can see this very easily - right-clicking on a JPEG file and selecting Properties, I get: Size: 35.1 KB (35,997 bytes) Size on disk: 48.0 KB (49,152 bytes) From the os.stat() docs: On some Unix systems (such as Linux), the following attributes may also be available: st_blocks (number of blocks allocated for file), st_blksize(filesystem blocksize), st_rdev (type of device if an inode device). st_flags (user defined flags for file). So apparently os.stat() can get this info from *nix, but not Windows... maybe behind the scenes, it runs du? -- www.fsrtechnologies.com ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Looking for something similar to du...
Mark is right...in that I don't want the actual size of the file itself...that I can get from another way in Python which i am already doing. I was mainly wondering if there was a way to do it and I was just missing something. I looked though stat() and that is basically what I wanted. I wasn't sure if that was actually it until Mark spelled it out for me. I do love using du...since I am learning..I just wanted make sure I wasn't missing anything...thank you guys as always... On Mon, May 5, 2008 at 6:57 PM, Marc Tompkins [EMAIL PROTECTED] wrote: On Mon, May 5, 2008 at 5:21 PM, Alan Gauld [EMAIL PROTECTED] wrote: Probably but I'm not totally clear what you are looking for. Can you explain what you mean by the diffrence between the size used versus the size of the image? Surely the size of the image is the space it uses? Or are you expanding compressed files? Disk space is allocated in large units (in DOS/Windows they're called clusters, *nixes call them blocks). A one-byte file still uses an entire cluster, whose size depends on the size of the disk and the number of chunks it can be divided into. So just knowing the size of the file is not quite enough information if you need to know how much room is left on the disk... If you use Windows, you can see this very easily - right-clicking on a JPEG file and selecting Properties, I get: Size: 35.1 KB (35,997 bytes) Size on disk: 48.0 KB (49,152 bytes) From the os.stat() docs: On some Unix systems (such as Linux), the following attributes may also be available: st_blocks (number of blocks allocated for file), st_blksize(filesystem blocksize), st_rdev (type of device if an inode device). st_flags (user defined flags for file). So apparently os.stat() can get this info from *nix, but not Windows... maybe behind the scenes, it runs du? -- www.fsrtechnologies.com ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor -- Spencer Parker ___ if you can't go to heaven, may you at least die in Ireland. ___ ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
