Talk:Truncate a file: Difference between revisions
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It's pretty clear that this task assumes unix file system semantics. So, can we ignore other operating systems in this task? --[[User:Rdm|Rdm]] 14:33, 19 July 2011 (UTC) |
It's pretty clear that this task assumes unix file system semantics. So, can we ignore other operating systems in this task? --[[User:Rdm|Rdm]] 14:33, 19 July 2011 (UTC) |
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:Why is it clear the task assumes unix behavior? --[[User:Ledrug|Ledrug]] 14:37, 19 July 2011 (UTC) |
:Why is it clear the task assumes unix behavior? --[[User:Ledrug|Ledrug]] 14:37, 19 July 2011 (UTC) |
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::Quoting http://www.conifersystems.com/2008/10/21/windows-vs-unix-file-system-semantics/ '''The Windows delete and rename model is different.''' You wouldn’t know this from the Win32 APIs, but in order to delete or rename a file in Windows, you first have to open it! Once you’ve opened it can you call NtSetInformationFile with InformationClass of FileDispositionInformation or FileRenameInformation. Setting FileDispositionInformation doesn’t even delete the file; it merely enables delete-on-close for the file, and the delete-on-close request could very well be cancelled later. |
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::As near as I can tell, you have to get rid of the association between a name and a file before you can give another file that name. --[[User:Rdm|Rdm]] 14:43, 19 July 2011 (UTC) |
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Revision as of 14:43, 19 July 2011
So just to be sure, if the actual file size is smaller than the given truncated size, it's an error? It doesn't just leave the file alone? --Mwn3d 14:09, 19 July 2011 (UTC)
- POSIX truncate() and ftruncate() extends the file if specified size is larger than original. It's convenient when you want to reserve some disk space. --Ledrug 14:25, 19 July 2011 (UTC)
Assumes unix
It's pretty clear that this task assumes unix file system semantics. So, can we ignore other operating systems in this task? --Rdm 14:33, 19 July 2011 (UTC)
- Why is it clear the task assumes unix behavior? --Ledrug 14:37, 19 July 2011 (UTC)
- Quoting http://www.conifersystems.com/2008/10/21/windows-vs-unix-file-system-semantics/ The Windows delete and rename model is different. You wouldn’t know this from the Win32 APIs, but in order to delete or rename a file in Windows, you first have to open it! Once you’ve opened it can you call NtSetInformationFile with InformationClass of FileDispositionInformation or FileRenameInformation. Setting FileDispositionInformation doesn’t even delete the file; it merely enables delete-on-close for the file, and the delete-on-close request could very well be cancelled later.
- As near as I can tell, you have to get rid of the association between a name and a file before you can give another file that name. --Rdm 14:43, 19 July 2011 (UTC)