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TrFile_GetFileHash |
Returns the MD5 or SHA1 hash value (checksum) of a file.
Syntax
TrFile_GetFileHash ( switches ; sourcefile )
Parameters
| switches | determines the behavior of the function |
| sourcefile | the path to the file of which you want the hash value, or container data |
Switches
Switches must be one of this:
| -MD5 | use the MD5 algorithm to calculate the hash. |
| -SHA1 | use the SHA-1 algorithm to calculate the hash. |
You can also add this switch below:
| -Colons | add colons between the result, for easy human reading |
Returned Result
Data type returned
Text
Result
the hash value, which is a text of 32 or 40 characters.
If the file does not exist or if an error occurs an error code will be returned, starting with $$. Returned error codes can be:
| $$-43 | fnfErr | File or folder not found |
| $$-50 | paramErr | Parameter error |
Originated in
Troi File Plug-in 6.0
Compatibility
FileMaker Pro 16 to FileMaker Pro 2023
Considerations
The function result is also called a message-digest. It provides an easy way to check if a file has not changed (by comparing it to a stored hash). Also you can use this hash to check if two files are identical.
Note: On macOS only the data fork of a file is considered. The resource fork of a file is ignored.
SHA-1 is considered more secure as it is a longer hash (160-bit).
Starting with v12.1: you can also use a container (or a variable with container data) as the source parameter, for example a JPEG in a container field
Example
TrFile_GetFileHash ( "-SHA1" ; "C:\Test.txt" ) ]This will return the SHA1 hash value which looks like this: “65c25a0c4ad167d9394298beaf93d0e630d2767a”
Example 2
Set Variable [ $hash ; TrFile_GetFileHash ( "-MD5 -Colons" ; "filemac:/Mac HD/Users/Smith/report.txt" ) ]This will set the variable $hash to the MD5 hash value of the file. The result will be formatted, for easier reading, with colons between each byte and looks similar to this:
“65:da:d9:97:46:2d:21:95:a7:4e:e8:a1:fd:5f:3c:ed”
Used in example file
Attribute.fmp12
Related functions
| TrFile_Exists |
| TrFile_GetCodeSignInfo |
| TrFile_GetFileSize |
| TrFile_GetTypeOfItem |
Related topics
Troi File Plug-in online help (overview)
