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| BOOL VerifyFile( |
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LPCTSTR lpszLocalFile, |
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LPCTSTR lpszRemoteFile, |
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DWORD dwOptions |
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The VerifyFile method attempts to verify that the contents
of a file on the local system are the same as the specified file on
the server.
Parameters
- lpszLocalFile
- A pointer to a string that specifies the name
of file on the local system.
- lpszRemoteFile
- A pointer to a string that specifies the name
of the file on the server.
- dwOptions
- Specifies the options that may be used when comparing the
files. This parameter may be one or more of the following
values:
| Value |
Description |
| FTP_VERIFY_DEFAULT |
File verification should use the best option available
based on the available server features. If the server supports
the XMD5 command, the class will calculate an MD5 hash of the
local file contents and compare the value with the file on the
server. If the server does not support the XMD5 command, but it
does support the XCRC command, the class will calculate a CRC32
checksum of the local file contents and compare the value with
the file on the server. If the server does not support either
the XMD5 or XCRC commands, the class will compare the size of
the local and remote files. |
| FTP_VERIFY_SIZE |
Files are verified by comparing the number of bytes of data
in the local and remote files. This is the least reliable
method, and should only be used if the server does not support
either the XMD5 or XCRC commands. |
| FTP_VERIFY_CRC32 |
Files are verified by calculating a CRC32 checksum of the
local file contents and comparing it with the value returned by
the server in response to the XCRC command. This method should
only be used if the server does not support the XMD5
command. |
| FTP_VERIFY_MD5 |
Files are verified by calculating an MD5 hash of the local
file contents and comparing it with the value returned by the
server in response to the XMD5 command. This is the preferred
method for performing file verification. |
Return Value
If the method succeeds, the return value is non-zero. If the
method fails, the return value is zero. To get extended error
information, call GetLastError.
Remarks
The VerifyFile method will attempt to verify that the
contents of the local and remote files are identical using one of
several methods, based on the features that the server supports.
Preference will be given to the most reliable method available, using
either an MD5 hash, a CRC32 checksum or comparing the size of the
file, in that order.
It is not recommended that you use this method with text files
because of the different end-of-line conventions used by different
operating systems. For example, a text file on a Windows system uses
a carriage-return and linefeed pair to indicate the end of a line of
text. However, on a UNIX system, a single linefeed is used to
indicate the end of a line. This can cause the VerifyFile
method to indicate the files are not identical, even though the only
difference is in the end-of-line characters that are used.
Requirements
Minimum Desktop Platform: Windows 7 (Service Pack 1)
Minimum Server Platform: Windows Server 2008 R2 (Service Pack 1)
Header File: cstools10.h
Import Library: csftpv10.lib
Unicode: Implemented as Unicode and ANSI versions.
See Also
DeleteFile,
GetFile, PutFile
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