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2025-12-03T15:49:58Z

Initial page creation.

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[[Category:Lua]]
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'''function''' md5file(''pathToFile'') ''':''' string

Calculates and returns the MD5 checksum of a file's contents. The result is returned as a lowercase hexadecimal string (32 hex characters). This is useful for integrity checks, detecting file changes, or verifying downloads.

=== Function Parameters ===
{|width="85%" cellpadding="10%" cellpadding="5%" cellspacing="0" border="0"
!align="left"|Parameter
!align="left"|Type
!style="width: 80%;" align="left"|Description
|-
| pathToFile
| string
| Path to the file to be hashed. Use an absolute or relative path. On Windows, backslashes (<code>\</code>) are allowed.
|}

=== Returns ===
A string containing the MD5 hash of the file in lowercase hexadecimal (e.g. <code>9e107d9d372bb6826bd81d3542a419d6</code>).

=== Description ===
The function opens the specified file, reads its bytes, computes the MD5 digest over the file contents, and returns the digest formatted as a 32-character hexadecimal string. If the file cannot be opened or read, the function may raise an error.

=== Usage Examples ===

<pre>
-- Simple usage
local hash = md5file("C:\\Games\\mygame.exe")
print("MD5: " .. hash) -- e.g. MD5: 9e107d9d372bb6826bd81d3542a419d6
</pre>

<code>Script Error:Unable to open file "C:\path\to\file.bin"</code>

=== Notes ===

* The function reads the raw bytes of the file; text encoding does not affect the hash.
* For very large files the operation can be slow and use memory depending on implementation.
* MD5 collisions are possible; do not use MD5 when collision resistance is required.
* When comparing MD5 strings, normalize case (lowercase) or use a case-insensitive comparison.

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