TrFile_GetFileHash (function reference)

By January 1, 2021January 26th, 2021Online Help, Troi File Plug-in
Troi File Plug-in > Functions reference > TrFile_GetFileHash
Troi File Plug-in for FileMaker Pro

TrFile_GetFileHash

Returns the MD5 or SHA1 hash value (checksum) of a file.

SyntaxFunction badge

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 19

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 functionsFunction badge

TrFile_Exists
TrFile_GetCodeSignInfo
TrFile_GetFileSize
TrFile_GetTypeOfItem

Related topics

Troi File Plug-in online help (overview)


Online Help Page for Troi File Plug-in for 16 to 19 –> TrFile_GetFileHash (filep4301) 2021-0126 10:49:56